Isometric force parameters and trunk muscle recruitment strategies in a population with low back pain, Descarreaux M, Lalonde C, Normand MC.

J Manipulative Physiol Ther. 2007 Feb;30(2):91-7.

OBJECTIVE: This study correlates changes in trunk isometric force parameters and trunk muscle recruitment strategies in subjects with low back pain (LBP) and healthy participants. METHODS: A control group study with repeated measures was performed. Study participants included 15 control subjects and 14 patients with LBP. Participants were required to exert 50% and 75% of their maximal trunk flexion and extension. In a learning phase, feedback was provided, after which study participants were asked to perform 10 trials without any feedback. Spatiotemporal parameters of muscular activity and force production were recorded. Dependent variables included time to peak force, peak force variability, absolute error in peak force, electromyogram (EMG) burst duration for agonist muscles, and normalized integrated EMG. RESULTS: Average time to peak force was significantly longer for subjects with LBP than for healthy subjects. Subjects with LBP showed longer burst duration for all 4 muscles recorded. No group difference was noted in normalized integrated EMG. CONCLUSIONS: We suggest that the observed changes in trunk motor control and trunk muscle recruitment strategies are not only mediated by a neurophysiologic adaptation to chronic pain but also by cognitive adaptations modulated by fear of movement and fear of reinjury.

Spinal muscle evaluation in healthy individuals and low-back-pain patients: a literature review, Demoulin C, Crielaard JM, Vanderthommen M.

Joint Bone Spine. 2007 Jan;74(1):9-13. Epub 2006 Nov 13.

Abstract: This article reviews available techniques for spinal muscle investigation, as well as data on spinal muscles in healthy individuals and in patients with low back pain. In patients with chronic low back pain, medical imaging studies show paraspinal muscle wasting with reductions in cross-sectional surface area and fiber density. In healthy individuals, the paraspinal muscles contain a high proportion of slow-twitch fibers (Type I), reflecting their role in maintaining posture. The proportion of Type I fibers is higher in females, leading to better adaptation to aerobic exertion compared to males. Abnormalities seen in paraspinal muscles from patients with chronic low back pain include marked Type II fiber atrophy, conversion of Type I to Type II fibers, and an increased number of nonspecific abnormalities. Limited data are available from magnetic resonance spectroscopy used to investigate muscle metabolism and from near infrared spectroscopy used to measure oxygen uptake by the paraspinal muscles. Surface electromyography in patients with chronic low back pain shows increased paraspinal muscle fatigability, often with abolition of the flexion-relaxation phenomenon.

Comment: This study demonstrates that LBP usually correlates with demonstrable muscle changes that will most likely to produce weakness upon testing.

EMG analysis of shoulder muscle fatigue during resisted isometric shoulder elevation,

Minning S, Eliot CA, Uhl TL, Malone TR.

J Electromyogr Kinesiol. 2006 Mar 16; [Epub ahead of print]

Abstract: The purpose of this study was to determine if a difference existed in the rate of fatigue of select shoulder muscles during isometric shoulder elevation and if the measured rate of fatigue was consistent from day to day. Shoulder muscle fatigue has been associated with alterations in joint mechanics and possibly contributes to shoulder dysfunction. While research exists, there is limited information on an objective and reliable measure of shoulder fatigue. Sixteen asymptomatic subjects were evaluated. The subjects held a weight equivalent to 60% of his/her Maximum Voluntary Isometric Contraction (MVIC) while elevating in the scapular plane. Surface electrodes were applied to collect electromyographic activity from the upper trapezius, middle deltoid, serratus anterior, and lower trapezius muscles while the arm was held at 90 degrees elevation. Data collection ceased when the subject was no longer able to maintain 90 degrees of elevation. The subject then rested and a second trial performed. One week later, the two-trial procedure was repeated. A significant interaction of trialxdayxmuscle was found for the rate of fatigue. Post hoc analysis revealed that the rate of fatigue of the middle deltoid was significantly greater than the other muscles tested. The intraday reliability was good for all muscles but interday reliability was poor except for the middle deltoid. This study suggests that the middle deltoid appears to fatigue faster than the other shoulder muscles tested at the selected level of shoulder elevation. This should be considered in designing a rehabilitation program to develop a sequence that does not overly fatigue the middle deltoid.

Reversible pelvic asymmetry: an overlooked syndrome manifesting as scoliosis, apparent leg-length difference, and neurologic symptoms, Timgren J, Soinila S.

J Manipulative Physiol Ther. 2006 Sep;29(7):561-5.

OBJECTIVE: The objective of this study was to investigate the occurrence of pelvic asymmetry in neurologic patients with symptoms not explained by their neurologic diagnosis. METHODS: We analyzed 150 consecutive neurologic patients referred to physiatric consultation based on their clinical examination findings. RESULTS: We observed pelvic asymmetry associated with either C-type or S-type scoliosis and apparent leg-length difference in 87% of the patients. Symmetry could be reestablished by all patients, although 15% showed immediate or imminent relapse. Maintenance of symmetry showed a highly significant (P < .001) correlation with improvement in functional ability and reduction of pain as evaluated during the last visit to the physiatrist. In the follow-up questionnaire, 78% of the patients reported improvement in functional ability and reduced pain. CONCLUSIONS: Our results support the view that leg-length difference and scoliosis may be more often of reversible nature than previously considered. Acquired postural asymmetry of the sacroiliac joint may be a neglected cause of several neurologic and other pain-related symptoms that can be relieved by a simple and safe treatment.

Effect of Counterstrain on Stretch Reflexes, Hoffmann Reflexes, and Clinical Outcomes in Subjects With Plantar Fasciitis, Wynne MW, Burns JM, Eland DC, Conatser RR, Howell JN.

JAOA Sept 2006;106(9):547-556.

Context: Previous research indicates that osteopathic manipulative treatmentbased on counterstrain produces a decrease in the stretch reflexof the calf muscles in subjects with Achilles tendinitis.Objectives: To study the effects of counterstrain on stretchreflex activity and clinical outcomes in subjects with plantarfasciitis.Methods: In a single-blind, randomized controlled trial of crossover design,the effects of counterstrain were compared with those of placeboin adult subjects (N=20) with plantar fasciitis. The subjectswere led to believe that both the counterstrain and placebowere therapeutic modalities whose effects were being compared.Ten subjects (50%) were assigned to receive 3 weeks of counterstraintreatment during phase 1 of the trial, while the other 10 subjectswere given placebo capsules. After a 2- to 4-week washout period, phase2 of the trial began with the interventions reversed. Clinicaloutcomes were assessed with daily questionnaires. Stretch reflexand H-reflex (Hoffmann reflex) in the calf muscles were assessedtwice during each laboratory visit, before and after treatmentin the counterstrain phase.Results: No significant changes in the electrically recorded reflexesof the calf muscles were observed in response to treatment.However, changes in the mechanical characteristics of the twitchesresulting from the electrical responses were observed. Peakforce and time to reach peak force both increased (P.05) inthe posttreatment measurements, with the increase being significantlymore pronounced in the counterstrain phase (P<.05). A comparisonof pretreatment and posttreatment symptom severity demonstratedsignificant relief of symptoms that was most pronounced immediatelyfollowing treatment and lasted for 48 hours.Conclusions: Clinical improvement occurs in subjects with plantar fasciitisin response to counterstrain treatment. The clinical responseis accompanied by mechanical, but not electrical, changes inthe reflex responses of the calf muscles. The causative relationbetween the mechanical changes and the clinical responses remainsto be explored.

A method for comparing manual muscle strength measurements with joint moments during walking, Fosang A, Baker R.

Gait Posture. 2006 Dec;24(4):406-11. Epub 2006 Jan 18.

Abstract: This paper describes a protocol for dynamometer assisted manual muscle testing of the major muscle groups of the lower extremity and its application to 11 able-bodied children who also had conventional gait analysis to obtain joint kinetics. Data from the manual muscle testing was processed in such a way that the results for maximum muscle strength (grade 5) and resistance against gravity alone (grade 3) were presented in Nm/kg allowing direct comparison with conventional joint kinetics. The strength measurements of the hip muscles and the knee extensors were between two and three times the moments exerted during normal walking. Those of the knee flexors and dorsiflexors were about five times the joint moments. Measured plantarflexor strength was only just greater than the moment exerted during walking. These results, particularly those for the plantarflexors, question how valid it is to use measures of isometric muscle strength as indicators of muscle function during activity. The study also compares grade 3 muscle strength with both grade 5 strength and the maximum joint moments. For all muscle groups tested grade 3 muscle strength was less than the maximum moment exerted during normal walking. For the plantarflexors it was less than 1% of that moment. The study demonstrates that reliable isometric muscle testing is possible in able-bodied children but requires considerable care and is time consuming. More work is required to understand how measurements made in this way relate to how muscles function during activity.

Comment:Many studies have compared the findings of MMT with dynamometer tests favorably, however dynamometers are not as sensitive to changes in strength nor to strength measurements below 3 during the MMT. The human examiner is the most sensitive of all instruments in relationship to interpreting the MMT.

Physiopathology of respiratory muscles, Close P, Dang MN, Bury T.

(Article in French)

Rev Med Liege. 2006 Apr;61(4):227-32.

Abstract: Different factors can have deleterious effect the inspiratory muscles: increased intrinsic mechanical loading of the inspiratory muscles, functional inspiratory muscle weakness, increased ventilatory demand related to capacity...These muscle changes influence exercise tolerance and contribute to dyspnea.

Conservative chiropractic management of recalcitrant foot pain after fasciotomy: a retrospective case review, Wyatt LH.

J Manipulative Physiol Ther. 2006 Jun;29(5):398-402.

OBJECTIVE: The objective of this study was to describe the safety and potential therapeutic benefit of joint mobilization and manipulation in the conservative management of patients with recalcitrant foot pain after plantar fasciotomy. METHODS: The study design was a retrospective review of outcomes of 15 patients seen in a multidisciplinary office setting. All patients had undergone plantar fasciotomy within the 9 months before their admission and had developed lateral foot pain after operation. Each patient had exhibited suboptimal improvement with at least a 4- to 6-week trial of nonsteroidal anti-inflammatory drugs, shoe padding, and rest as prescribed by the attending podiatric surgeon. Manual therapy consisted of either grade III or grade IV joint mobilization and/or high-velocity, low-amplitude chiropractic manipulation to the affected joints in the foot and ankle, and home-based exercise. Outcome criteria were empirically defined as significant improvement, moderate improvement, or no change as assessed by each patient based on a verbal rating scale. RESULTS: There was no long-lasting complication associated with any of the procedures, although a common pattern of transient pain migration over the dorsum of the foot into the ankle was noted in some patients; this resolved by the time of discharge. Of the patients with pain in the calcaneocuboid and/or fifth tarsometatarsal articulation, 11 noted significant improvement, 3 experienced moderate improvement, and 1 reported no change. Patients who complied with home care instructions responded better to therapy in most instances. CONCLUSIONS: These preliminary findings suggest that joint mobilization and manipulation are safe conservative procedures to use in the treatment of patients with lateral column foot pain in status post plantar fasciotomy.

Comment: When muscles fail to support the arch of the foot the ligaments can be stretched, and the medial longitudinal arch of the foot is lost. The many causes of foot pronation, which produces plantar fascitis in many cases, are evaluated in AK including the ligaments, muscles, and joints of the foot and leg.

The effect of chiropractic adjustments on movement time: a pilot study using Fitts Law, Smith DL, Dainoff MJ, Smith JP.

J Manipulative Physiol Ther. 2006 May;29(4):257-66.

OBJECTIVE: To investigate the effect of chiropractic adjustments on movement time using Fitts Law. METHODS: This was a prospective, randomized controlled trial. Ten patients from a private chiropractic practice participated. Participants in the treatment group received high-velocity, low-amplitude chiropractic adjustments to areas of joint dysfunction (chiropractic subluxation). A nonintervention group was used to control for improvement resulting from time and practice effects. Movement time was measured as participants moved a cursor onto a target appearing on a computer screen. A range of target widths and target distances were used to vary the index of difficulty. RESULTS: All participants in the experimental group had significantly improved movement times following spinal adjustments compared with only 1 participant in the control group. The average improvement in movement time for the experimental group was 183 ms, a 9.2% improvement, whereas the average improvement in movement time for the control group was 29 ms, a 1.7% improvement. The difference (improvement) scores after the intervention were significantly greater for the chiropractic group compared with the control group as measured by a 2-tailed independent samples t test (P < .05). CONCLUSION: The results of this study demonstrated a significant improvement in movement time with chiropractic care. These results suggest that spinal adjustments may influence motor behavior.

Comment: Movement time (MT) is an important variable influencing how people control their movements. At the elite sport level even small changes in MT can have a large effect. For instance, differences between the personal best times of the top sprinters in the world in the 100 yard dash can differ by only 1% (i.e. Greene 9.79 seconds, Bailey 9.84 s, and Christie 9.87 s). MT improvement following treatment has been related to Parkinson’s disease severity also. This study demonstrates another investigation into the potential motor control and functional improvements in chiropractic patients.

Improvement in paraspinal muscle tone, autonomic function and quality of life in four children with cerebral palsy undergoing subluxation based chiropractic care: Four retrospective case studies and review of the literature, McCoy M, Malakhova E, Safronov Y, Kent C, Scire P.

J Vertebral Subluxation Research, June 21, 2006:1-15.

Objective: To review the literature and present results experienced by four children with cerebral palsy who underwent chiropractic care to reduce vertebral subluxation. Clinical Features: Four children previously diagnosed with cerebral palsy secondary to birth trauma. All four demonstrated objective evidence of vertebral subluxation. Intervention and Outcomes: Chiropractic care directed at reduction of subluxation was undertaken. Paraspinal surface electromyography and thermography readings were taken prior to the initiation of care and approximately one month (12 visits) later. The mothers and care providers in each case monitored changes in activities of daily living and quality of life. All four children showed improvement in paraspinal muscle tone (improved symmetry and decreased amplitude) as well as a decrease in the number of levels of abnormal thermography readings. All four children showed improvement in activities of daily living including mobility, feeding, and postural control. Conclusion: Improvement in muscle tone and autonomic function coupled with improvement in activities of daily living occurred in these four patients undergoing chiropractic care for reduction of vertebral subluxation. It is suggested that larger studies of this nature be carried out.

The effect of sacroiliac joint manipulation on feed-forward activation times of the deep abdominal musculature,
Marshall P, Murphy B.

J Manipulative Physiol Ther. 2006 Mar-Apr;29(3):196-202.

OBJECTIVES: To determine the incidence of delayed feed-forward activation (FFA) times in a group of healthy young males; to retest those subjects who showed delayed FFA after 6 months to determine the reliability of the measure in the absence of treatment or injury in the intervening period; and to determine the effect of sacroiliac joint manipulation on delayed FFA times. METHODS: Ninety young males were assessed for the FFA of their deep abdominal muscles in relation to rapid upper limb movements. Those who met the criteria for delayed FFA (failure of deep abdominal activation within 50 milliseconds of deltoid activation) were then reassessed 6 months later. These subjects then underwent sacroiliac joint manipulation on the side demonstrating decreased joint movement during hip flexion and lateral flexion. Feed-forward activation times were then reassessed after joint manipulation. RESULTS: Seventeen (18.9%) of 90 subjects met the criteria of impaired FFA. Thirteen of 17 were available to be remeasured at 6-month follow-up. The intraclass correlation coefficient for FFA at this time was greater than 0.70 for all movement directions. There was a significant improvement (38.4%) in FFA times for this group when remeasured immediately after the sacroiliac joint manipulation. CONCLUSIONS: Delayed FFA is a highly reproducible measure at long-term follow-up. This technique appears to be a sensitive marker of the neural effects of sacroiliac joint manipulation. Future prospective studies are needed to determine if delayed FFA times are a marker for those at risk for developing back pain.

Comment: This study demonstrates that an immediately measurable change in muscle function and synergism with other muscles in the body occurs after SI joint manipulation.

Whiplash injury and oculomotor dysfunctions: clinical-posturographic correlations, Storaci R, Manelli A, Schiavone N, Mangia L, Prigione G, Sangiorgi S.

Eur Spine J. 2006 Mar 22

Abstract: Oculomotor dysfunctions are hidden causes of invalidity following whiplash injury. Many patients with whiplash injury grade II present oculomotor dysfunctions related to input disturbances of cervical or vestibular afferents. We used static posturography to investigate 40 consecutive patients with whiplash injury grade II and oculomotor dysfunctions. We demonstrated a relation between length and surface of body sway: the surface value (A) was higher than the length value (L) and this led to an open graph of body sway in the statokinesigram. Oculomotor rehabilitation can resolve the impairment of vestibular function but if therapy is delayed or the patient has been wearing an orthopaedic neck collar, more therapeutic sessions are required. In conclusion, without rehabilitation of the oculomotor muscles other therapies are not sufficient to recover the impairment caused by whiplash injury.

Comment: Patients who have experienced cervical trauma from whiplash dynamics often have perplexing symptoms. The standard orthopedic and neurologic examination often does not find a cause for the bizarre symptoms about which some patients complain. Manual muscle testing is a method for evaluating the function of the nervous system; it often reveals the cause, giving an understanding of the patient's many complaints. Failure to recognize problems in the motor system in whiplash patients, and failure to correct it is often the reason a patient is labeled as being a malingerer or having a psychoneurotic overlay to his condition, and is one of the reasons why symptoms from whiplash injuries can persist for many years. In this report oculomotor dysfunction was present in 62% of the patients affected by whiplash injury. The opening of this paper’s Abstract states the problem: “Oculomotor dysfunctions are hidden causes of invalidity following whiplash injury.” In applied kinesiology chiropractic methodology, a means for testing the integration of the muscles in the body with the visual reflexes has been termed ocular lock.  Ocular lock testing demonstrates the failure of the eyes to work together on a binocular basis through the cardinal fields of gaze.  This is usually not gross pathology of cranial nerves III, IV, and VI; rather it is poor functional organization. The ocular lock phenomenon is theorized to be a consequence, most frequently, to cranial faults.  Diagnosis of the oculomotor function in patients with post-whiplash syndromes has been expedited by AK testing.

Diagnostic accuracy of the neurological upper limb examination I: inter-rater reproducibility of selected findings and patterns, Jepsen JR, Laursen LH, Hagert CG, Kreiner S, Larsen AI.

BMC Neurol. 2006 Feb 16;6:8.

BACKGROUND: We have previously assessed the reproducibility of manual testing of the strength in 14 individual upper limb muscles in patients with or without upper limb complaints. This investigation aimed at additionally studying sensory disturbances, the mechanosensitivity of nerve trunks, and the occurrence of physical findings in patterns which may potentially reflect a peripheral neuropathy. The reproducibility of this part of the neurological examination has never been reported. METHODS: Two blinded examiners performed a semi-quantitative assessment of 82 upper limbs (strength in 14 individual muscles, sensibility in 7 homonymous territories, and mechanosensitivity of nerves at 10 locations). Based on the topography of nerves and their muscular and cutaneous innervation we defined 10 neurological patterns each suggesting a focal neuropathy. The individual findings and patterns identified by the two examiners were compared. RESULTS: Strength, sensibility to touch, pain and vibration, and mechanosensitivity were predominantly assessed with moderate to very good reproducibility (median kappa-values 0.54, 0.69, 0.48, 0.58, and 0.53, respectively). The reproducibility of the defined patterns was fair to excellent (median correlation coefficient = 0.75) and the overall identification of limbs with/without pattern(s) was good (kappa = 0.75). CONCLUSION: This first part of a study on diagnostic accuracy of a selective neurological examination has demonstrated a promising inter-rater reproducibility of individual neurological items and patterns. Generalization and clinical feasibility require further documentation: 1) Reproducibility in cohorts of other composition, 2) validity with comparison to currently applied standards, and 3) potential benefits that can be attained by the examination.

Disorders of breathing and continence have a stronger association with back pain than obesity and physical activity,
Smith MD Russell A, Hodges PW.

Aust J Physiother. 2006;52(1):11-6.

Abstract: Although obesity and physical activity have been argued to predict back pain, these factors are also related to incontinence and breathing difficulties. Breathing and continence mechanisms may interfere with the physiology of spinal control, and may provide a link to back pain. The aim of this study was to establish the association between back pain and disorders of continence and respiration in women. We conducted a cross-sectional analysis of self-report, postal survey data from the Australian Longitudinal Study on Women's Health. We used multinomial logistic regression to model four levels of back pain in relation to both the traditional risk factors of body mass index and activity level, and the potential risk factors of incontinence, breathing difficulties, and allergy. A total of 38,050 women were included from three age-cohorts. When incontinence and breathing difficulties were considered, obesity and physical activity were not consistently associated with back pain. In contrast, odds ratios (OR) for often having back pain were higher for women often having incontinence compared to women without incontinence (OR were 2.5, 2.3 and 2.3 for young, mid-age and older women, respectively). Similarly, mid-aged and older women had higher odds of having back pain often when they experienced breathing difficulties often compared to women with no breathing problems (OR of 2.0 and 1.9, respectively). Unlike obesity and physical activity, disorders of continence and respiration were strongly related to frequent back pain. This relationship may be explained by physiological limitations of co-ordination of postural, respiratory and continence functions of trunk muscles.

Comment: This study confirms a frequent clinical finding in AK, i.e. that problems with respiration involving the phrenic and intercostals nerves affect may produce incontinence in patients. Correction of problems that produce an elevated level of CO₂ in the blood, using AK methods of treatment, can improve the management and outcome of patients with incontinence.

A pilot study comparing the effects of spinal manipulative therapy with those of extra-spinal manipulative therapy on quadriceps muscle strength, Hillermann B, Gomes AN, Korporaal C, Jackson D.

J Manipulative Physiol Ther, 2006 Feb;29(2):145-9.

OBJECTIVE: The objective of this study was to assess whether tibiofemoral joint manipulation is as effective as sacroiliac (SI) joint manipulation in increasing quadriceps muscle strength. DESIGN AND SETTING: Twenty subjects were divided into two groups of 10. After all base measurements of the maximum voluntary force of the quadriceps muscles were taken, subjects in group A received tibiofemoral joint manipulation and those in group B received ipsilateral SI joint manipulation. After these treatments, the maximum voluntary forces of the subjects' quadriceps muscles were retested. RESULTS: A significant improvement (P = .05) in quadriceps muscle strength was noted in the subjects who received an SI joint manipulation. CONCLUSION: This study showed a significant change within the SI joint manipulation group before and after the manipulation but did not show any significant difference between the groups (tibiofemoral joint vs. SI joint manipulation) in increasing quadriceps muscle strength.

Comment: This study demonstrates that an immediately measurable change in muscle strength, from inhibition to strength, occurs after SI joint manipulation. A weakness in this study’s design is that the manipulation of the tibiofemoral joint was a long-axis manipulation of the joint. There was no evaluation done as to whether this joint had any mechanical problem or subluxation present within it. A more specific design would have been to compose group B of subjects who had knee pain in the area of the tibiofemoral joint. Better yet would have been to find subjects for group B who had specific dysfunctions of the tibiofemoral joint. After manipulating the subluxated tibiofemoral joint into proper position, an evaluation of the inhibited quadriceps muscle might have found an improvement in it strength upon testing. In AK, adjustment of the articulations of the knee frequently improves the function of the quadriceps muscle, as does adjustment of the SI joint when it is subluxated.

A prospective randomized controlled trial of spinal manipulation and ultrasound in the treatment of chronic low back pain, Mohammad A, Mohseni-Bandpei, Critchley J, Staunton T, Richardson B

Physiotherapy 92(1) March 2006, Pages 34-42

Objectives. To assess the short- and long-term effectiveness of spinal manipulation therapy, and to identify the effect of manipulation on lumbar muscle endurance in patients with chronic low back pain (LBP). Design. A randomized controlled trial comparing manipulation and exercise treatment with ultrasound and exercise treatment. Setting An outpatient physiotherapy department. Participants One hundred and twenty patients with chronic LBP were allocated at random into the manipulation/exercise group or the ultrasound/exercise group. Interventions Both groups were given a program of exercises. In addition, one group received spinal manipulation therapy and the other group received therapeutic ultrasound. Main outcome measures Pain intensity, functional disability, lumbar movements and muscle endurance were measured shortly before treatment, at the end of the treatment program and 6 months after randomization using surface electromyography. Results Following treatment, the manipulation/exercise group showed a statistically significant improvement (P = 0.001) in pain intensity [mean 16.4 mm, 95% confidence interval (CI) 6.1–26.8], functional disability (mean 8%, 95% CI 2–13) and spinal mobility (flexion: mean 9.4 mm, 95% CI 5.5–13.4; extension: mean 3.4 mm, 95% CI 1.0–5.8). There was no significant difference (P = 0.068) between the two groups in the median frequency of surface electromyography (multifidus: mean 6.8 Hz, 95% CI 1.24–14.91; iliocostalis: mean 2.4 Hz, 95% CI 2.5–7.1), although a significant difference (P = 0.013) was found in the median frequency slope of surface electromyography in favor of spinal manipulation for multifidus alone (mean 0.3, 95% CI 0.1–0.5). A significant difference was also found between the two groups in favor of the manipulation/exercise group at 6-month follow-up. Conclusions Although improvements were recorded in both groups, patients receiving manipulation/exercise showed a greater improvement compared with those receiving ultrasound/exercise at both the end of the treatment period and at 6-month follow-up.

Reliability of techniques to assess human neuromuscular function in vivo, Clark BC, Cook SB, Ploutz-Snyder LL

J Electromyogr Kinesiol. 2006 Jan 18

Abstract: The purpose of this study was to comprehensively evaluate the reliability of a large number of commonly utilized experimental tests of in vivo human neuromuscular function separated by 4-weeks. Numerous electrophysiological parameters (i.e., voluntary and evoked electromyogram [EMG] signals), contractile properties (i.e., evoked forces and rates of force development and relaxation), muscle morphology (i.e., MRI-derived cross-sectional area [CSA]) and performance tasks (i.e., steadiness and time to task failure) were assessed from the plantarflexor muscle group in 17 subjects before and following 4-weeks where they maintained their normal lifestyle. The reliability of the measured variables had wide-ranging levels of consistency, with coefficient of variations (CV) ranging from approximately 2% to 20%, and intraclass correlation coefficients (ICC) between 0.53 and 0.99. Overall, we observed moderate to high-levels of reliability in the vast majority of the variables we assessed (24 out of the 29 had ICC>0.70 and CV<15%). The variables demonstrating the highest reliability were: CSA (ICC=0.93-0.98), strength (ICC=0.97), an index of nerve conduction velocity (ICC=0.95), and H-reflex amplitude (ICC=0.93). Conversely, the variables demonstrating the lowest reliability were: the amplitude of voluntary EMG signal (ICC=0.53-0.88), and the time to task failure of a sustained submaximal contraction (ICC=0.64). Additionally, relatively little systematic bias (calculated through the limits of agreement) was observed in these measures over the repeat sessions. In conclusion, while the reliability differed between the various measures, in general it was rather high even when the testing sessions are separated by a relatively long duration of time.

Evaluation of Apparent and Absolute Supraspinatus Strength in Patients With Shoulder Injury Using the Scapular Retraction Test, Kibler WB, Sciascia A, Dome D.

Am J Sports Med. 2006 May 30; [Epub ahead of print]

BACKGROUND: Physical examination of patients with shoulder injury not involving actual rotator cuff tears frequently demonstrates decreased rotator cuff strength on manual muscle testing. This decrease has been attributed to supraspinatus muscle weakness, but it may be owing to alterations in scapular position. HYPOTHESIS: The position of stabilized scapular retraction, by minimizing proximal kinetic chain factors and providing a stable base of muscle origin, positively influences demonstrated supraspinatus strength. STUDY DESIGN: Controlled laboratory study. METHODS: Supraspinatus strength was tested in 20 injured patients and 10 healthy controls in both the empty-can arm position and a position of scapular retraction using a handheld dynamometer. Pain in both maneuvers was measured by use of a visual analog scale. RESULTS: Paired t tests indicated the scapular retraction position resulted in statistically significantly (P = .001) higher supraspinatus strength values within both groups. There was no significant difference between the 2 positions in visual analog scale scores. CONCLUSION: This study shows that demonstrated apparent supraspinatus weakness on clinical examination in symptomatic patients may be dependent on scapular position. The weakness may be owing to other factors besides supraspinatus muscle weakness, such as a lack of a stable base in the kinetic chain or scapula. CLINICAL RELEVANCE: The clinical examination that addresses scapular posture and includes scapular retraction will allow more accurate determination of absolute supraspinatus muscle strength and allow efficacious rehabilitation protocols to address the source of the demonstrated weakness.

Comment: In AK, precise positioning of the patient is critical to consistently dependable findings in MMT. There are many synergistic muscles to the muscle being primarily evaluated during MMT, and these muscles must be correlated to make final determination of the muscle’s function. Proper muscle testing is the key to an effective examination. Poor or inexact testing may result in misinformation or in the wrong choice of therapies.

The visceromotor responses to colorectal distension and skin pinch are inhibited by simultaneous jejunal distension, Shafton AD, Furness JB, Ferens D, Bogeski G,  Koh SL, Lean NP, Kitchener PD.

Pain. 2006 Jul;123(1-2):127-36. Epub 2006 May 16.

Abstract: Noxious stimuli that are applied to different somatic sites interact; often one stimulus diminishes the sensation elicited from another site. By contrast, inhibitory interactions between visceral stimuli are not well documented. We investigated the interaction between the effects of noxious distension of the colorectum and noxious stimuli applied to the jejunum, in the rat. Colorectal distension elicited a visceromotor reflex, which was quantified using electromyographic (EMG) recordings from the external oblique muscle of the upper abdomen. The same motor units were activated when a strong pinch was applied to the flank skin. Distension of the jejunum did not provoke an EMG response at this site, but when it was applied during colorectal distension it blocked the EMG response. Jejunal distension also inhibited the response to noxious skin pinch. The inhibition of the visceromotor response to colorectal distension was prevented by local application of tetrodotoxin to the jejunum, and was markedly reduced when nicardipine was infused into the local jejunal circulation. Chronic sub-diaphragmatic vagotomy had no effect on the colorectal distension-induced EMG activity or its inhibition by jejunal distension. The nicotinic antagonist hexamethonium suppressed phasic contractile activity in the jejunum, had only a small effect on the inhibition of visceromotor response by jejunal distension. It is concluded that signals that arise from skin pinch and colorectal distension converge in the central nervous system with pathways that are activated by jejunal spinal afferents; the jejunal signals strongly inhibit the abdominal motor activity evoked by noxious stimuli.

Measurement of electrical skin impedance of dermal-visceral zones as a diagnostic tool for inner organ pathologies: a blinded preliminary evaluation of a new technique, Zimlichman E,

Lahad A, Aron-Maor A Kanevsky A, Shoenfeld Y.

Isr Med Assoc J. 2005 Oct;7(10):631-4

BACKGROUND: As complementary and alternative medicine is gaining popularity among health consumers, diagnostic screening tools based on neuroreflexology are also being developed. These techniques, which are based on the rationale that measurement of electrical impedance of specific dermatomes reflects corresponding internal organ pathologies, have not yet been the subject of conventional scientific research. OBJECTIVES: To determine the effectiveness of a neuroreflexology-based screening test, specifically the Medex device (Medex Screen Ltd.), for diagnosing patients undergoing conventional internal organ assessment, in a hospital setting. METHODS: Patients admitted to an internal medicine department, who met the inclusion criteria and agreed to participate, underwent conventional medical evaluation that included past medical history and physical examination. Another examination was conducted by a second physician using the Medex device to determine internal organ pathologies. A third researcher compared the actual "conventional" diagnosis with the Medex device output using standard statistical analysis. RESULTS: Overall, 150 patients participated in the study. Correlation was significant for all categories (P < 0.01) except for blood and lymphatic disease. A high sensitivity (>70%) was measured for cardiovascular, respiratory, gastrointestinal and genitourinary diseases. The highest measure of agreement, as represented by the Cohen-Kappa factor, was found for respiratory disease (0.57). CONCLUSIONS: Although the exact mechanism is not entirely clear, measurement of electroskin impedance of dermal-visceral zones has the potential to serve as a screening tool for inner organ pathologies. Further research should be conducted to create more evidence to support or dispute the use of this technique as a reliable diagnostic tool.

Comment: This study demonstrates a small part of the potentiality of the AK technique called Therapy Localization or TL. In AK, TL is a simple, non-invasive technique to find out where a problem in the body exists. TL doesn’t show the physician what the problem is but shows that something under the hand that is contacting the patient’s body is disturbing the nervous system.

Modulation of intracortical excitability in human hand motor areas. The effect of cutaneous stimulation and its topographical arrangement, Ridding MC, Pearce SL, Flavel SC.

Exp Brain Res. 2005 Jun;163(3):335-43. Epub 2005 Jan 15

Abstract: Changes in afferent input can alter the excitability of intracortical inhibitory systems. For example, using paired transcranial magnetic stimulation (TMS), both electrical digital stimulation and muscle vibration have been shown to reduce short-interval intracortical inhibition (SICI). The effects following muscle vibration are confined to the corticospinal projection to the vibrated muscles. The results following digital stimulation are less clear and the relative timing of the cutaneous stimulation and TMS is critical. Here we investigated further whether changes in SICI following digit stimulation exhibit topographic specificity. Eleven normal subjects were investigated (age 28.2+/-7.5 years, mean+/-SD). Electromyographic recordings were made from the right first dorsal interosseous (FDI), abductor digiti minimi (ADM) and abductor pollicis brevis (APB) muscles. SICI was measured, with and without preceding electrical digit II or digit V cutaneous stimulation. The interval between the digital nerve stimulus and test magnetic stimulus was independently set for each subject and established by subtracting the onset latency of the motor evoked potential (MEP) from the latency of the E2 component of the cutaneomuscular reflex. Therefore, measures of intracortical excitability were made at a time at which it is known that cutaneous input is capable of modulating cortical excitability. Single digital nerve stimuli applied to digit II significantly reduced SICI in FDI but not in ADM. Single digital nerve stimuli applied to digit V significantly reduced SICI in ADM but not in FDI or APB. There was a more generalised effect on intracortical facilitation (ICF) with both digit II and digit V stimulation significantly increasing ICF in FDI and ADM. Digital stimulation (either DII or DV) did not significantly affect SICI/ICF in APB. These findings show that appropriately timed cutaneous stimuli are capable of modulating SICI in a topographically specific manner. We suggest that the selective decrease in SICI seen with cutaneous stimulation may be important for focusing of muscle activation during motor tasks.

Comment: This study demonstrates also a small part of the potentiality of the AK technique called Therapy Localization or TL. The cutaneomuscular reflexes have been extensively investigated in the scientific literature, and they are part of the mechanism for what is found clinically with TL testing.

Delayed trunk muscle reflex responses increase the risk of low back injuries, Cholewicki J, Silfies SP, Shah R, Greene HS, Reeves NP, Alvi K, Goldberg B

Spine. 2005 Dec 1;30(23):2614-20.

STUDY DESIGN: Prospective observational study with a 2- to 3-year follow-up. OBJECTIVES: To determine whether delayed muscle reflex response to sudden trunk loading is a result of or a risk factor for sustaining a low back injury (LBI). SUMMARY OF BACKGROUND DATA: Differences in motor control have been identified in individuals with chronic low back pain and in athletes with a history of LBI when compared with controls. However, it is not known whether these changes are a risk for or a result of LBI. METHODS: Muscle reflex latencies in response to a quick force release in trunk flexion, extension, and lateral bending were measured in 303 college athletes. Information was also obtained regarding their personal data, athletic experience, and history of LBI. The data were entered into a binary logistic regression model to identify the predictors of future LBI. RESULTS: A total of 292 athletes were used for the final analysis (148 females and 144 males). During the follow-up period, 31 (11%) athletes sustained an LBI. The regression model, consisting of history of LBI, body weight, and the latency of muscles shutting off during flexion and lateral bending load releases, predicted correctly 74% of LBI outcomes. The odds of sustaining LBI increased 2.8-fold when a history of LBI was present and increased by 3% with each millisecond of abdominal muscle shut-off latency. On average, this latency was 14 milliseconds longer for athletes who sustained LBI in comparison to athletes who did not sustain LBI (77 [36] vs. 63 [31]). There were no significant changes in any of the muscle response latencies on retest following the injury. CONCLUSIONS: The delayed muscle reflex response significantly increases the odds of sustaining an LBI. These delayed latencies appear to be a preexisting risk factor and not the effect of an LBI.

Trunk muscle recruitment patterns in specific chronic low back pain populations, Silfies SP, Squillante D, Maurer P, Westcott S, Karduna AR.

Clin Biomech (Bristol, Avon). 2005 Jun;20(5):465-73.

BACKGROUND: It is hypothesized that injury or degeneration of osteoligamentous spinal structures would require compensation by trunk musculature and alterations in motor control to maintain spine stability. While, biomechanical modeling has supported this hypothesis, studies of muscle recruitment patterns in chronic low back pain patients both with and without significant osteoligamentous damage have been limited. This study utilized a non-randomized case-control design to investigate trunk muscle recruitment patterns around the neutral spine position between subgroups of patients with chronic mechanical low back pain and asymptomatic controls. METHODS: Twenty subjects with chronic low back pain attributed to clinical lumbar instability were matched to 20 asymptomatic controls. In addition 12 patients with non-specific chronic low back pain were studied. Surface EMG from five trunk muscles was analyzed to determine activation levels and patterns of recruitment during a standing reach under two different loading conditions. FINDINGS: The chronic low back pain group with symptoms attributed to clinical instability demonstrated significantly higher activation levels of the external oblique and rectus abdominus muscles and lower abdominal synergist ratios than the control group. No significant differences were found between patient subgroups. INTERPRETATION: While these data demonstrate altered muscle recruitment patterns in patients with chronic low back pain, the changes are not consistent with Panjabi's theory suggesting that these alterations are driven by passive subsystem damage. However, the higher activation of global abdominal musculature and altered synergist patterns may represent a motor control pattern that has consequences for continued dysfunction and chronic pain.

Comment: In this compendium of evidence for the AK approach to health care there have been more than 20 studies documenting that motor control does not function properly in patients with chronic LBP and neck pain. This type of muscular dysfunction, recognized as critical in patients with LBP and neck pain, involves the disruption of the what Dr. Panjabi terms the stability system of the spine, leading to the suggestion that improper stabilization responses may serve as a perpetuating factor in patients. It would therefore be beneficial for clinicians to have at their disposal simple, reliable, and accurate tests that are capable of detecting the disturbance of these motor control responses and of monitoring the effectiveness of treatment measures designed to correct this dysfunction. AK MMT provides this type of simple, reliable, repeatable physical test.

A model of dynamic sacro–iliac joint instability from malrecruitment of gluteus maximus and biceps femoris muscles resulting in low back pain, Hossain M, Nokes LDM.

Medical Hypotheses, 2005;65(2):278-281.

Effect of gaze direction on neck muscle activity during cervical rotation, Bexander CS, Mellor R, Hodges PW.

Exp Brain Res. 2005 Dec;167(3):422-32. Epub 2005 Sep 29.

Abstract: Control of the neck muscles is coordinated with the sensory organs of vision, hearing and balance. For instance, activity of splenius capitis (SC) is modified with gaze shift. This interaction between eye movement and neck muscle activity is likely to influence the control of neck movement. The aim of this study was to investigate the effect of eye position on neck muscle activity during cervical rotation. In eleven subjects we recorded electromyographic activity (EMG) of muscles that rotate the neck to the right [right obliquus capitis inferior (OI), multifides (MF), and SC, and left sternocleidomastoid (SCM)] with intramuscular or surface electrodes. In sitting, subjects rotated the neck in each direction to specific points in range that were held statically with gaze either fixed to a guide (at three different positions) that moved with the head to maintain a constant intra-orbit eye position or to a panel in front of the subject. Although right SC and left SCM EMG increased with rotation to the right, contrary to anatomical texts, OI EMG increased with both directions and MF EMG did not change from the activity recorded at rest. During neck rotation SCM and MF EMG was less when the eyes were maintained with a constant intra-orbit position that was opposite to the direction of rotation compared to trials in which the eyes were maintained in the same direction as the head movement. The inter-relationship between eye position and neck muscle activity may affect the control of neck posture and movement.

Comment: In applied kinesiology chiropractic methodology, a means for testing the integration of the muscles in the body with the visual reflexes has been termed ocular lock. It demonstrates the failure of the eyes to work together on a binocular basis through the cardinal fields of gaze.  This is usually not gross pathology of cranial nerves III, IV, and VI; rather it is poor functional organization. Mechanical irritation of cranial nerves III, IV, or VI (usually VI) may be responsible for disturbed binocular function leading to discordant sensory inputs from the visual righting reflex. When the eyes are turned in a specific direction, a previously strong indicator muscle will weaken when the ocular lock test is positive. AK evaluation makes the discovery of dysfunction between the movement of the eyes and their coordination with the muscles of the neck possible in the clinical setting.

Myotendinous alterations and effects of resistive loading in old age, Narici M, Maganaris C, Reeves N.

-- Institute for Biophysical and Clinical Research into Human Movement (IRM), Manchester Metropolitan University

Scand J Med Sci Sports. 2005 Dec;15(6):392-401.

Abstract: The loss of muscle mass associated with ageing only partly explains the observed decline in muscle strength. This paper provides evidence of the contribution of muscular, tendinous and neural alterations to muscle weakness in old age and discusses the complex interplay between the changes of the contractile tissue with those of the tendinous tissue in relation to the mechanical behavior of the muscle as a whole. Despite the considerable structural and functional alterations, the elderly musculoskeletal system displays remarkable adaptability to training in old age and many of these adverse effects may be substantially mitigated, if not reversed, by resistive loading. The interplay between these muscular and tendinous adaptations has an impact both on the length-force and force-velocity relationships of the muscle and is likely to affect the range of motion, rate of force development, maximum force development and speed of movement of the older individual.

Erector Spinae and Quadratus Lumborum Muscle Endurance Tests and Supine Leg-Length Alignment Asymmetry: An Observational Study, Knutson, G., Owens, E.

J Manipulative Physiol Ther, 2005;28(8):575-581

Objective: To determine if there is an association between supine leg-length alignment (LLA) asymmetry and the endurance of the erector spinae (ES) and quadratus lumborum (QL) muscles. Methods: Forty-seven subjects (21 women; average age, 36 years old) were tested for ES endurance using the Biering-Sorensen (B-S) test, and 69 (31 women; average age, 34.5 years) were tested for QL endurance. Subjects were examined for supine LLA and tested for ES and QL muscle endurance. The muscle endurance times were compared against those who did and did not demonstrate LLA asymmetry and the side of the “short leg.” Results: In the B-S test, volunteers with LLA asymmetry (n = 27) had a mean endurance time of 89.7 seconds (SD, 43.3), and the no-LLA asymmetry group (n = 20) had a mean endurance time of 161.5 seconds (SD, 57.1), a significant difference (P < .001). In the QL test, after correction for the effects of sex and exercise, those with a right “short leg” (n = 22) had a right QL endurance time of 25.9 seconds (SE, 4.2) and a left QL endurance time of 34.7 seconds (SE, 4.3). The right QL endurance time was significantly different from those subjects with balanced legs (P = .001). Those with a left “short leg” (n = 20) had a left QL endurance time of 28.6 seconds (SE, 4.7) and a right QL endurance time of 38.1 seconds (SE, 4.5). Both QL endurance times were significantly different from those with balanced leg-length (P = .002 and .016, respectively). Conclusion: This study suggests that, using the B-S test, the group of volunteers who demonstrated a commonly used sign of subluxation/joint dysfunction, supine LLA asymmetry, had a decreased endurance times over those who did not. The QL endurance tests showed that the QL muscle ipsilateral to the supine short leg had significantly decreased endurance times over the same-side QL fatigue times in the no leg-length asymmetry group.

Spinal manipulation alters electromyographic activity of paraspinal muscles: a descriptive study, DeVocht J, Pickar J, Wilder D.

J Manipulative Physiol Ther, 2005;28(7):465-471

Objective: To examine the effect of spinal manipulation on electromyographic (EMG) activity in areas of localized tight muscle bundles of the low back.Methods: Surface EMG activity was collected from 16 participants in 2 chiropractic offices during the 5 to 10 minutes of the treatment protocol. Electrodes were placed over the 2 sites of greatest paraspinal muscle tension as determined by manual palpation. Spinal manipulation was administered to 8 participants using Activator protocol; the other 8 were treated using Diversified protocol. Results: Electromyographic activity decreased by at least 25% after treatment in 24 of the 31 sites that were monitored. There was less than 25% change at 3 sites and more than 25% increase at 4 sites. Multiple distinct increases and decreases were observed in many data plots.Conclusion: The results of this study indicate that manipulation induces a virtually immediate change, usually a reduction, in resting EMG levels in at least some patients with low back pain and tight paraspinal muscle bundles. In some cases, EMG activity increased during the treatment protocol and then usually, but not always, decreased to a level lower than the pretreatment level.

A hypothesis of chronic back pain: ligament subfailure injuries lead to muscle control dysfunction, Panjabi M.

Eur Spine J. 2005 Jul 27

Abstract: Clinical reports and research studies have documented the behavior of chronic low back and neck pain patients. A few hypotheses have attempted to explain these varied clinical and research findings. A new hypothesis, based upon the concept that subfailure injuries of ligaments (spinal ligaments, disc annulus and facet capsules) may cause chronic back pain due to muscle control dysfunction, is presented. The hypothesis has the following sequential steps. Single trauma or cumulative microtrauma causes subfailure injuries of the ligaments and embedded mechanoreceptors. The injured mechanoreceptors generate corrupted transducer signals, which lead to corrupted muscle response pattern produced by the neuromuscular control unit. Muscle coordination and individual muscle force characteristics, i.e. onset, magnitude, and shut-off, are disrupted. This results in abnormal stresses and strains in the ligaments, mechanoreceptors and muscles, and excessive loading of the facet joints. Due to inherently poor healing of spinal ligaments, accelerated degeneration of disc and facet joints may occur. The abnormal conditions may persist, and, over time, may lead to chronic back pain via inflammation of neural tissues. The hypothesis explains many of the clinical observations and research findings about the back pain patients. The hypothesis may help in a better understanding of chronic low back and neck pain patients, and in improved clinical management.

Comment: This is one of the most important articles published to date on the musculoskeletal aspects of the subluxation. Dr. Panjabi is the world’s most published human biomechanical researcher, with 263 published articles to date. The hypothesis he presents in this paper places the functionality of muscles, as both a cause and a consequence of mechanoreceptor dysfunction in chronic back pain patients, at the center of a sequence of events that ultimately results in back pain. As a result of spinal subluxations, muscle coordination and individual muscle force characteristics, i.e. inhibited muscles on MMT, are disrupted. The injured mechanoreceptors generate corrupted transducer signals (that could be detected by EMG, dynamometers, or MMT), which lead to corrupted muscle response patterns produced by the neuromuscular control unit.  This article is very important for those in the chiropractic profession who are evaluating the existence and the consequences of the subluxation. The key technical factor that makes AK indispensable in the detection of spinal dysfunction is the MMT that makes the detection of muscular imbalance verifiable.

Parallel comparison of grip strength measures obtained with a MicroFET 4 and a Jamar dynamometer, Bohannon RW.

-- Department of Physical Therapy, School of Allied Health, U-2101, University of Connecticut, Storrs, CT 06269-2101, USA.

Percept Mot Skills. 2005 Jun;100(3 Pt 1):795-8.

Abstract:Repeated measures of grip strength obtained bilaterally with a Jamar and a MicroFET 4 dynamometer were compared. Measurements obtained with the MicroFET 4 tended to be slightly (2.2-3.1 lb.) higher but were highly correlated (r > or = .96) with those obtained with the Jamar. Parallel reliability for the two devices was excellent (intraclass correlation coefficient > or = .96). Although clinicians should be cautious about using the devices interchangeably, the MicroFET 4 appears to be a legitimate alternative to the Jamar dynamometer.

Quantifying shoulder rotation weakness in patients with shoulder impingement, Tyler TF, Nahow RC, Nicholas SJ, McHugh MP.

-- Nicholas Institute of Sports Medicine and Athletic Trauma, Lenox Hill Hospital, New York, NY, USA; PRO Sports Physical Therapy of Westchester, New York, NY, USA.

J Shoulder Elbow Surg. 2005 Nov-Dec;14(6):570-4.

Abstract: The purpose of this study was to determine whether strength deficits could be detected in individuals with and without shoulder impingement, all of whom had normal shoulder strength bilaterally according to grading of manual muscle testing. Strength of the internal rotators and external rotators was tested isokinetically at 60 degrees /s and 180 degrees /s, as well as manually with a handheld dynamometer (HHD) in 17 patients and 22 control subjects. Testing was performed with the shoulder positioned in the scapular plane and in 90 degrees of shoulder abduction with 90 degrees of elbow flexion (90-90). The peak torque was determined for each movement. The strength deficit between the involved and uninvolved arms (patients) and the dominant and nondominant arms (control subjects) was calculated for each subject. Comparisons were made for the scapular-plane and 90-90 positions between isokinetic and HHD testing. Despite a normal muscle grade, patients had marked weakness (28% deficit, P < .01) in external rotators at the 90-90 position tested with the HHD. In contrast, external rotator weakness was not evident with isokinetic testing at the 90-90 position (60 degrees /s and 180 degrees /s, 0% deficit, P = .99). In control subjects, greater internal rotator strength in the dominant compared with the nondominant arm was evident with the HHD at the 90-90 position (11%, P < .01) and in the scapular plane (7%, P < .05). Using an HHD while performing manual muscle testing can quantify shoulder strength deficits that may not be apparent with isokinetic testing. By using an HHD during shoulder testing, clinicians can identify weakness that may have been presumed normal.

Scapular muscle tests in subjects with shoulder pain and functional loss: reliability and construct validity, Michener LA, Boardman ND, Pidcoe PE, Frith AM.

Phys Ther. 2005 Nov;85(11):1128-38.

BACKGROUND AND PURPOSE: Scapular muscle performance evaluated with a handheld dynamometer (HHD) has been investigated only in people without shoulder dysfunction for test-retest reliability of data obtained with a single scapular muscle test. The purpose of this study was to assess the reliability, error, and validity of data obtained with an HHD for 4 scapular muscle tests in subjects with shoulder pain and functional loss. SUBJECTS AND METHODS: Subjects (N=40) with shoulder pain and functional loss were tested by measuring the kilograms applied with an HHD during 3 trials for muscle tests for the lower trapezius, upper trapezius, middle trapezius, and serratus anterior muscles. Concurrently, surface electromyography (sEMG) data were collected for the 4 muscles. The same procedures were performed 24 to 72 hours after the initial testing by the same tester. Muscle tests were performed 3 times, and the results were averaged for data analysis. RESULTS: Intraclass correlation coefficients for intratester reliability of measurements of isometric force obtained using an HHD ranged from .89 to .96. The standard error of the measure (90% confidence interval [CI]) ranged from 1.3 to 2.7 kg; the minimal detectable change (90% CI) ranged from 1.8 to 3.6 kg. Construct validity assessment, done by comparing the amounts of isometric muscle activity (sEMG) for each muscle across the 4 muscle tests, revealed that the muscle activity of the upper trapezius and lower trapezius muscles was highest during their respective tests. Conversely, the isometric muscle activity of the middle trapezius and serratus anterior muscles was not highest during their respective tests. DISCUSSION AND CONCLUSION: In people with shoulder pain and functional loss, the intrarater reliability and error over 1 to 3 days were established using an HHD for measurement of isometric force for the assessment of scapular muscle performance. Error values can be used to make decisions regarding individual patients. Construct validity was established for the lower and upper trapezius muscle tests; therefore, these tests are advocated for use. However, construct validity was not demonstrated for the serratus anterior and middle trapezius muscle tests as performed in this study. Further investigation of these muscle tests is warranted.

Comment: The correlation between MMT and HHD findings has been established in much of the research literature. This paper shows that there is a construct validity and reliability to employing MMT and HHD testing in patients with shoulder injuries.

Hip muscle weakness and overuse injuries in recreational runners, Niemuth PE, Johnson RJ, Myers MJ, Thieman TJ.

Clin J Sport Med. 2005 Jan;15(1):14-21.

OBJECTIVE: To test for differences in strength of 6 muscle groups of the hip on the involved leg in recreational runners with injuries compared with the uninvolved leg and a control group of noninjured runners. DESIGN: Descriptive analysis. SETTING: Three outpatient physical therapy clinics in the Minneapolis/St. Paul metropolitan area. PARTICIPANTS: Thirty recreational runners (17 female, 13 male) experiencing a single leg overuse injury that presented for treatment between June and September 2002. Thirty noninjured runners (16 female, 14 male) randomly selected from a pool of 46 volunteers from a distance running club served as controls. MAIN OUTCOME MEASURES: Self-report demographic information on running habits, leg dominance demonstrated by preferred kicking leg, and injury information. Muscle strength of the 6 major muscle groups of the hip was recorded using a hand-held dynamometer. The highest value of 2 trials was used, and strength values were normalized to body mass(2/3). RESULTS: Results comparing the injured and noninjured groups showed that leg dominance did not influence the leg of injury (chi(2)(1) = 0.134; P = 0.71). Correlations for internal reliability of muscle measurements between trials 1 and 2 with the hand-held dynamometer ranged from 0.80 to 0.90 for the 6 muscle groups measured, and all P values were less than 0.0001. No significant side-to-side differences in hip group muscle strength were found in the noninjured runners (P = 0.62-0.93). Among the injured runners, the injured side hip abductor (P = 0.0003) and flexor muscle groups (P = 0.026) were significantly weaker than the noninjured side. In addition, the injured side hip adductor muscle group was significantly stronger (P = 0.010) than the noninjured side. Duration of symptoms was not a contributing factor to the extent of injury as measured by muscle strength imbalance between injured and uninjured sides. CONCLUSIONS: Although no cause-and-effect relationship has been established, this is the first study to show an association between hip abductor, adductor, and flexor muscle group strength imbalance and lower extremity overuse injuries in runners. Because most running injuries are multifaceted in nature, areas secondary to the site of pain, such as hip muscle groups exhibiting strength imbalances, must also be considered to gain favorable outcomes for injured runners. The addition of strengthening exercises to specifically identified weak hip muscles may offer better treatment results in patients with running injuries.

Comment: This study shows an important evidence-based component of the treatment of hip and pelvic problems in runners as being methods of strengthening the weak muscles around the hip and to improve muscular balance, the sine qua non of AK treatment.

Long-term follow-up of a randomized clinical trial assessing the efficacy of medication, acupuncture, and spinal manipulation for chronic mechanical spinal pain syndromes, Muller R, Giles LG.

J Manipulative Physiol Ther. 2005 Jan;28(1):3-11.

OBJECTIVE: To assess the long-term benefits of medication, needle acupuncture, and spinal manipulation as exclusive and standardized treatment regimens in patients with chronic (>13 weeks) spinal pain syndromes. STUDY DESIGN: Extended follow-up (>1 year) of a randomized clinical trial was conducted at the multidisciplinary spinal pain unit of Townsville's General Hospital between February 1999 and October 2001. PATIENTS AND METHODS: Of the 115 patients originally randomized, 69 had exclusively been treated with the randomly allocated treatment during the 9-week treatment period (results at 9 weeks were reported earlier). These patients were followed up and assessed again 1 year after inception into the study reapplying the same instruments (i.e., Oswestry Back Pain Index, Neck Disability Index, Short-Form-36, and Visual Analogue Scales). Questionnaires were obtained from 62 patients reflecting a retention proportion of 90%. The main analysis was restricted to 40 patients who had received exclusively the randomly allocated treatment for the whole observation period since randomization. RESULTS: Comparisons of initial and extended follow-up questionnaires to assess absolute efficacy showed that only the application of spinal manipulation revealed broad-based long-term benefit: 5 of the 7 main outcome measures showed significant improvements compared with only 1 item in each of the acupuncture and the medication groups. CONCLUSIONS: In patients with chronic spinal pain syndromes, spinal manipulation, if not contraindicated, may be the only treatment modality of the assessed regimens that provides broad and significant long-term benefit.

Muscle reflex classification of low-back pain, Reeves NP, Cholewicki J, Milner TE.

J Electromyogr Kinesiol. 2005 Feb;15(1):53-60. Epub 2004 Nov 21.

Abstract: It has been well documented that low-back pain (LBP) patients have longer muscle response latencies to perturbation than healthy controls. These muscle responses appear to be reflexive and not voluntary in nature, and as a result, might be useful for objectively classifying LBP. The goal of the study was to develop an objective and accurate method for classifying LBP using a sudden load-release protocol. Subjects were divided into two groups: learning group (20 patients and 20 controls), and holdout group (15 patients and 12 controls). Subjects exerted isometric trunk force against a cable in four different directions. Following cable release, the trunk was suddenly displaced eliciting a muscle reflex response. Reflex latencies for muscles switching-on and shutting-off were determined using electromyogram signals from 8 trunk muscles. Independent t tests were performed on the learning group to determine which reflex parameters were to be entered into logistic regression analysis to produce a classification model. The holdout group was used to validate this classification model. The three-parameter model was able to correctly classify 83% of the learning group, and 81% of the holdout group. Using reflex parameters appears to be an accurate and objective method for classifying LBP.

Motor unit synchronization is reduced in anterior knee pain,
Mellor R, Hodges PW.

J Pain. 2005 Aug;6(8):550-8.

Abstract: Anterior knee pain (AKP) is common and has been argued to be related to poor patellofemoral joint control due to impaired coordination of the vasti muscles. However, there are conflicting data. Changes in motor unit firing may provide more definitive evidence. Synchronization of motor unit action potentials (MUAPs) in vastus medialis obliquus (VMO) and vastus lateralis (VL) may contribute to coordination in patellofemoral joint control. We hypothesized that synchronization may be reduced in AKP. Recordings of single MUAPs were made from VMO and multiunit electromyograph (EMG) recordings were made from VL. Averages of VL EMG recordings were triggered from the single MUAPs in VMO. Motor units in VL firing in association with the VMO motor units would appear as a peak in the VL EMG average. Data were compared to previous normative data. The proportion of trials in which a peak was identified in the triggered averages of VL EMG was reduced in people with AKP (38%) compared to controls (90%). Notably, although 80% of subjects had values less than controls, 20% were within normal limits. These results provide new evidence that motor unit synchronization is modified in the presence of pain and provide evidence for motor control dysfunction in AKP. PERSPECTIVE: This study shows that coordination of motor units between the medial and lateral vasti muscles in people with anterior knee pain is reduced compared to people without knee pain. It confirms that motor control dysfunction is a factor in this condition and has implications for selection of rehabilitation strategies.

Comment: This study suggests that in some cases, correcting knee pain is often as simple as correcting the muscles that stabilize the knee. AK evaluation of knee dysfunction always involves testing the knee-supporting muscles’ function.

Chronic spinal pain: a randomized clinical trial comparing medication, acupuncture, and spinal manipulation, Giles LG, Muller R.

Spine. 2005 Jan 1;30(1):166.

STUDY DESIGN: A randomized controlled clinical trial was conducted. OBJECTIVE: To compare medication, needle acupuncture, and spinal manipulation for managing chronic (>13 weeks duration) spinal pain because the value of medicinal and popular forms of alternative care for chronic spinal pain syndromes is uncertain. SUMMARY OF BACKGROUND DATA: Between February 1999 and October 2001, 115 patients without contraindication for the three treatment regimens were enrolled at the public hospital's multidisciplinary spinal pain unit. METHODS: One of three separate intervention protocols was used: medication, needle acupuncture, or chiropractic spinal manipulation. Patients were assessed before treatment by a sports medical physician for exclusion criteria and by a research assistant using the Oswestry Back Pain Disability Index (Oswestry), the Neck Disability Index (NDI), the Short-Form-36 Health Survey questionnaire (SF-36), visual analog scales (VAS) of pain intensity and ranges of movement. These instruments were administered again at 2, 5, and 9 weeks after the beginning of treatment. RESULTS: Randomization proved to be successful. The highest proportion of early (asymptomatic status) recovery was found for manipulation (27.3%), followed by acupuncture (9.4%) and medication (5%). Manipulation achieved the best overall results, with improvements of 50% (P = 0.01) on the Oswestry scale, 38% (P = 0.08) on the NDI, 47% (P < 0.001) on the SF-36, and 50% (P < 0.01) on the VAS for back pain, 38% (P < 0.001) for lumbar standing flexion, 20% (P < 0.001) for lumbar sitting flexion, 25% (P = 0.1) for cervical sitting flexion, and 18% (P = 0.02) for cervical sitting extension. However, on the VAS for neck pain, acupuncture showed a better result than manipulation (50% vs. 42%). CONCLUSIONS: The consistency of the results provides, despite some discussed shortcomings of this study, evidence that in patients with chronic spinal pain, manipulation, if not contraindicated, results in greater short-term improvement than acupuncture or medication. However, the data do not strongly support the use of only manipulation, only acupuncture, or only nonsteroidal anti-inflammatory drugs for the treatment of chronic spinal pain. The results from this exploratory study need confirmation from future larger studies.

Navigating a sensorimotor loop, Fanselow EE, Connors BW.

Neuron. 2005 Feb 3;45(3):329-30.

Abstract: Touch is an active process, but how do the body's somatic sensors influence its movement? In this issue of Neuron, Nguyen and Kleinfeld show that afferent activity from the whiskers on a rat's face trigger rapid and prolonged excitation of the motor neurons that drive movements of the same whiskers. Positive feedback through this sensorimotor loop may serve to optimize the interaction between sensors and stimuli.

Comment:This study demonstrates that there exists a sensori-motor loop that may be responsible for changes in muscle strength after tactile stimulation. This paper shows a small part of the potentiality of the AK technique called Therapy Localization or TL. The cutaneomuscular reflexes have been extensively investigated in the scientific literature, and they may be a part of the mechanism for what is found clinically with TL testing.

Evidence for strong synaptic coupling between single tactile afferents from the sole of the foot and motoneurons supplying leg muscles, Fallon JB Bent LR, McNulty PA, Macefield VG.

J Neurophysiol. 2005 Dec;94(6):3795-804. Epub 2005 Aug 3.

Abstract: It has been known for some time that populations of cutaneous and muscle afferents can provide short-latency facilitation of motoneuron pools. Recently, it has been shown that the input from individual low-threshold mechanoreceptors in the glabrous skin of the hand can modulate ongoing activity in muscles acting on the fingers via spinally mediated pathways. We have extended this work to examine whether such strong synaptic coupling exists between tactile afferents in the sole of the foot and motoneurons supplying muscles that act about the ankle. We recorded from 53 low-threshold mechanoreceptors in the glabrous skin of the foot via microelectrodes inserted percutaneously into the tibial nerve of awake human subjects. Reflex modulation of ongoing whole muscle electromyography (EMG) was observed for each of the four classes of low-threshold cutaneous mechanoreceptors (17 of 21 rapidly adapting type I; 2 of 4 rapidly adapting type II; 7 of 18 slowly adapting type I; and 4 of 10 slowly adapting type II). Reflex modulation of the firing probability in single motor units (5 of 11) was also observed. These results indicate that strong synaptic coupling between tactile afferents and spinal motoneurons is not a specialization of the hand and emphasizes the potential importance of cutaneous inputs from the sole of the foot in the control of gait and posture.

Comment:This study demonstrates that stimulation of the skin may be responsible for changes in muscle strength. This paper shows a small part of the potentiality of the AK technique called Therapy Localization or TL. The cutaneomuscular reflexes have been extensively investigated in the scientific literature, and they may be a part of the mechanism for what is found clinically with TL testing.

Measurement of electrical skin impedance of dermal-visceral zones as a diagnostic tool for inner organ pathologies: a blinded preliminary evaluation of a new technique, Zimlichman E, Lahad A, Aron-Maor A, Kanevsky A, Shoenfeld Y.

Isr Med Assoc J. 2005 Oct;7(10):631-4.

BACKGROUND: As complementary and alternative medicine is gaining popularity among health consumers, diagnostic screening tools based on neuroreflexology are also being developed. These techniques, which are based on the rationale that measurement of electrical impedance of specific dermatomes reflects corresponding internal organ pathologies, have not yet been the subject of conventional scientific research. OBJECTIVES: To determine the effectiveness of a neuroreflexology-based screening test, specifically the Medex device (Medex Screen Ltd.), for diagnosing patients undergoing conventional internal organ assessment, in a hospital setting. METHODS: Patients admitted to an internal medicine department, who met the inclusion criteria and agreed to participate, underwent conventional medical evaluation that included past medical history and physical examination. Another examination was conducted by a second physician using the Medex device to determine internal organ pathologies. A third researcher compared the actual "conventional" diagnosis with the Medex device output using standard statistical analysis. RESULTS: Overall, 150 patients participated in the study. Correlation was significant for all categories (P < 0.01) except for blood and lymphatic disease. A high sensitivity (>70%) was measured for cardiovascular, respiratory, gastrointestinal and genitourinary diseases. The highest measure of agreement, as represented by the Cohen-Kappa factor, was found for respiratory disease (0.57). CONCLUSIONS: Although the exact mechanism is not entirely clear, measurement of electroskin impedance of dermal-visceral zones has the potential to serve as a screening tool for inner organ pathologies. Further research should be conducted to create more evidence to support or dispute the use of this technique as a reliable diagnostic tool.

Comment:This study demonstrates that the electrodermal reflexes of the skin may be reflective of internal organ pathologies. The cutaneomuscular reflexes have been extensively investigated in the scientific literature, and new research is now showing that electro-dermal impedance measurements of the skin may serve as a screening tool for inner organ pathologies. The significance of these findings to the AK concepts of therapy localization may be evident to the reader.

Neck flexor muscle fatigue is side specific in patients with unilateral neck pain, Falla D, Jull G, Rainoldi A, Merletti R.

Eur J Pain. 2004 Feb;8(1):71-7.

Abstract: Despite the evidence of greater fatigability of the cervical flexor muscles in neck pain patients, the effect of unilaterality of neck pain on muscle fatigue has not been investigated. This study compared myoelectric manifestations of sternocleidomastoid (SCM) and anterior scalene (AS) muscle fatigue between the painful and non-painful sides in patients with chronic unilateral neck pain. Myoelectric signals were recorded from the sternal head of SCM and the AS muscles bilaterally during sub-maximal isometric cervical flexion contractions at 25% and 50% of the maximum voluntary contraction (MVC). The time course of the mean power frequency, average rectified value and conduction velocity of the electromyographic signals were calculated to quantify myoelectric manifestations of muscle fatigue. Results revealed greater estimates of the initial value and slope of the mean frequency for both the SCM and AS muscles on the side of the patient's neck pain at 25% and 50% of MVC. These results indicate greater myoelectric manifestations of muscle fatigue of the superficial cervical flexor muscles ipsilateral to the side of pain. This suggests a specificity of the effect of pain on muscle function and hence the need for specificity of therapeutic exercise in the management of neck pain patients.

Impairment in the cervical flexors: a comparison of whiplash and insidious onset neck pain patients, Jull G,

Kristjansson E, Dall'Alba P.

Man Ther. 2004 May;9(2):89-94.

Abstract: There has been little investigation into whether or not differences exist in the nature of physical impairment associated with neck pain of whiplash and insidious origin. This study examined the neck flexor synergy during performance of the cranio-cervical flexion test, a test targeting the action of the deep neck flexors. Seventy-five volunteer subjects participated in this study and were equally divided between Group 1, asymptomatic control subjects, Group 2, subjects with insidious onset neck pain and Group 3, subjects with neck pain following a whiplash injury. The cranio-cervical flexion test was performed in five progressive stages of increasing cranio-cervical flexion range. Subjects' performance was guided by feedback from a pressure sensor inserted behind the neck which monitored the slight flattening of the cervical lordosis which occurs with the contraction of longus colli. Myoelectric signals (EMG) were detected from the muscles during performance of the test. The results indicated that both the insidious onset neck pain and whiplash groups had higher measures of EMG signal amplitude (normalized root mean square) in the sternocleidomastoid during each stage of the test compared to the control subjects (all P<0.05) and had significantly greater shortfalls from the pressure targets in the test stages (P<0.05). No significant differences were evident between the neck pain groups in either parameter indicating that this physical impairment in the neck flexor synergy is common to neck pain of both whiplash and insidious origin.

Chronic back pain is associated with decreased prefrontal and thalamic gray matter density, Apkarian AV, Sosa Y, Sonty S, Levy RM, Harden RN, Parrish TB, Gitelman DR

J Neurosci. 2004 Nov 17;24(46):10410-5.

Abstract: The role of the brain in chronic pain conditions remains speculative. We compared brain morphology of 26 chronic back pain (CBP) patients to matched control subjects, using magnetic resonance imaging brain scan data and automated analysis techniques. CBP patients were divided into neuropathic, exhibiting pain because of sciatic nerve damage, and non-neuropathic groups. Pain-related characteristics were correlated to morphometric measures. Neocortical gray matter volume was compared after skull normalization. Patients with CBP showed 5-11% less neocortical gray matter volume than control subjects. The magnitude of this decrease is equivalent to the gray matter volume lost in 10-20 years of normal aging. The decreased volume was related to pain duration, indicating a 1.3 cm3 loss of gray matter for every year of chronic pain. Regional gray matter density in 17 CBP patients was compared with matched controls using voxel-based morphometry and nonparametric statistics. Gray matter density was reduced in bilateral dorsolateral prefrontal cortex and right thalamus and was strongly related to pain characteristics in a pattern distinct for neuropathic and non-neuropathic CBP. Our results imply that CBP is accompanied by brain atrophy and suggest that the pathophysiology of chronic pain includes thalamocortical processes.

Comment: The relationship between spinal malfunction and cerebral malfunction, specifically greatly accelerated atrophy of the brain, is an important concept for the chiropractic profession. This is especially important in light of the research articles that document that chiropractic spinal adjustments are more effective in treating chronic spinal pain when compared to medication, exercise, and needle acupuncture.

Hypothyroidism: A New Model for Conservative Management in Two Cases, Bablis, P. and Pollard, H.

Chiro J Aust, 2004;34:11-18

Objective:To review the function, anatomy, physiology, development, hormone synthesis and dysfunction of the thyroid gland. Treatment options are discussed, and 2 case studies of a mind-body therapy (Neuro-Emotional Technique—NET) successfully managing hypothyroid dysfunction are presented. Data Sources: MEDLINE search using key words: thyroid, synthesis, development, anatomy, physiology, hyperthyroidism and hypothyroidism. Data Selection: Eighty-five papers fit the key words and were selected based on relevance to the topic. Papers were selected that contained relevant information on normal andabnormal thyroid function and its management. Data Extraction: Selected papers had to contain information that directly related to the diagnosis, anatomy, physiology and management of hypothyroid conditions. Papers were also selected that described a possible neurophysiological mechanism for the observed treatment effects. Data Synthesis:Objective measures of a new mind-body approach to hypothyroid dysfunction are presented, and its relevance to the biopsychosocial model is discussed. This new treatment is compared to the existing biomedical approaches to treatment. Conclusion: Thyroid dysfunction has been effectively treated with medicine for many years. This paper presents a new therapy that produced objective pre-post changes to hypothyroid dysfunction in 2 cases. This therapy may have potential in future circumstances, with further research recommended to confirm its reliability/validity.

Reliability of hand-held dynamometry in assessment of knee extensor strength after hip fracture, Roy, MA, Doherty, TJ.

-- School of Kinesiology, University of Western Ontario, London, Ontario, Canada.

Am J Phys Med Rehabil. 2004 Nov;83(11):813-8.

OBJECTIVES:To examine the reliability of hand-held dynamometry in assessing knee extensor strength in inpatients undergoing rehabilitation after hip fracture and to examine the discriminant validity of this measure.  DESIGN: A total of 16 subjects (14 women; mean +/- SD, 79 +/- 7 yrs) undergoing inpatient rehabilitation after hip fracture volunteered to participate. Isometric knee extensor strength of the fractured and unfractured sides was determined with a hand-held dynamometer. Subjects were retested 1-2 days after the initial testing session.  RESULTS: Test-retest intraclass correlation coefficients were high for both the fractured (0.91) and unfractured legs (0.90). A low coefficient of variation was observed for both the fractured (15.3%) and unfractured (14.7%) sides. The maximal knee extensor strength was significantly different when comparing the fractured (7.9 +/- 3 kg) and unfractured (15.6 +/- 4 kg) legs. When comparing test 1 and test 2 mean values for the fractured leg, the scores significantly differed (t = 3.14, P < 0.01), with 13 of 16 subjects scoring higher on test 2.  CONCLUSIONS: Hand-held dynamometry is a reliable and valid tool for assessment of knee extensor strength after hip fracture. Reduced knee extensor strength in the fractured leg may be an important component limiting rehabilitation progress in these patients.

Differences in motor recruitment and resulting kinematics between low back pain patients and asymptomatic participants during lifting exertions, Ferguson SA, Marras WS, Burr DL, Davis KG, Gupta P.

Clin Biomech (Bristol, Avon). 2004 Dec;19(10):992-9.

BACKGROUND: Low back disorders are a prevalent problem in society today and may lead to chronic debilitating low back pain. Developing our understanding of temporal muscle and kinematic patterns during manual material handling tasks may provide insight for preventing the cascading series of events leading to chronic low back pain. METHODS: Sixty-two low back pain patients and 61 asymptomatic participants performed a variety of lifting exertions that varied in lift origin horizontal and vertical distance, lift asymmetry, and weight. Electromyographic activity of 10 trunk muscles as well as trunk and pelvic kinematics was recorded during each exertion. Differences in muscle activation and kinematic parameters were compared between low back pain patients and asymptomatic participants as a function of experimental conditions. FINDINGS: Both the left and right erector spinae activated significantly earlier and were on significantly longer in low back pain patients compared to asymptomatic participants. The horizontal and vertical location of the lift influenced the EMG and kinematic differences between the low back pain patients and asymptomatic participants. INTERPRETATION: These finding indicate that low back pain patients would be exposed to increase muscle activity resulting in higher spine loads for a greater length of time compared to asymptomatic participants. The longer exposure time to increased spine load may lead to greater risk of future low back injury and cascading events leading to debilitating low back pain. The longer muscle activation time suggests that low back pain patients have changed their motor program from an open to a closed loop system.

Changes in recruitment of the abdominal muscles in people with low back pain: ultrasound measurement of muscle activity, Ferreira PH, Ferreira ML, Hodges PW.

Spine. 2004 Nov 15;29(22):2560-6.

STUDY DESIGN: Ultrasound and electromyographic (EMG) measures of trunk muscle activity were compared between low back pain (LBP) and control subjects in a cross-sectional study. OBJECTIVES: To compare the recruitment of the abdominal muscles (measured as a change in thickness with ultrasound imaging) between people with and without low back pain and to compare these measurements with EMG recordings made with intramuscular electrodes. SUMMARY OF BACKGROUND DATA: Although ultrasonography has been advocated as a noninvasive measure of abdominal muscle activity, it is not known whether it can provide a valid measure of changes in motor control of the abdominal muscles in LBP. METHODS: Ten subjects with recurrent LBP and 10 matched controls were tested during isometric low load tasks with their limbs suspended. Changes in thickness from resting baseline values were obtained for transversus abdominis (TrA), obliquus internus (OI), and obliquus externus (OE) using ultrasonography. Fine wire EMG was measured concurrently. RESULTS: Study participants with LBP had a significantly smaller increase in TrA thickness with isometric leg tasks compared with controls. No difference was found between groups for OI or OE. Similar results were found for EMG. People with LBP had less TrA EMG activity with leg tasks, and there was no difference between groups for EMG activity for OI or OE. CONCLUSIONS: This study reinforces evidence for changes in automatic control of TrA in people with LBP. Furthermore, the data establish a new test of recruitment of the abdominal muscles in people with LBP. This test presents a feasible noninvasive test of automatic recruitment of the abdominal muscles.

Comment: Manual muscle testing is an obvious, feasible, and noninvasive test for the adequate recruitment of the abdominal muscles in patients with low back pain. The inhibition of the abdominal muscles in patients with low back pain is a consistent finding in AK therapeutics.

Delayed onset of transversus abdominus in long-standing groin pain, Cowan SM, Schache AG, Brukner P, Bennell KL, Hodges PW, Coburn P, Crossley KM.

Med Sci Sports Exerc. 2004 Dec;36(12):2040-5.

Abstract: Long-standing groin pain is a persistent problem that is commonly difficult to rehabilitate. Theoretical rationale indicates a relationship between the motor control of the pelvis and long-standing groin pain; however, this link has not been investigated. PURPOSE: The current experiment aimed to evaluate motor control of the abdominal muscles in a group of Australian football players with and without long-standing groin pain. METHODS: Ten participants with long-standing groin pain and 12 asymptomatic controls were recruited for the study. Participants were elite or subelite Australian football players. Fine-wire and surface electromyography electrodes were used to record the activity of the selected abdominal and leg muscles during a visual choice reaction-time task (active straight leg raising). RESULTS: When the asymptomatic controls completed the active straight leg raise (ASLR) task, the transversus abdominus contracted in a feed-forward manner. However, when individuals with long-standing groin pain completed the ASLR task, the onset of transversus abdominus was delayed (P < 0.05) compared with the control group. There were no differences between groups for the onset of activity of internal oblique, external oblique, and rectus abdominus (all P > 0.05). CONCLUSIONS: The finding that the onset of transversus abdominus is delayed in individuals with long-standing groin pain is important, as it demonstrates an association between long-standing groin pain and transversus abdominus activation.

Changes in the cross-sectional area of multifidus and psoas in patients with unilateral back pain: the relationship to pain and disability, Barker KL, Shamley DR, Jackson D.

Spine. 2004 Nov 15;29(22):E515-9.

STUDY DESIGN: Prospective, cross-sectional observational study. OBJECTIVES: The aim of this study was to determine if there was an association between wasting of psoas and multifidus as observed on MRI scans and the presenting symptoms, reported pathology, pain, or disability of a cohort of patients presenting with unilateral low back pain. SUMMARY OF BACKGROUND DATA: Current physiotherapy practice is often based on localized spine stabilizing muscle exercises; most attention has been focused on transversus abdominus and multifidus with relatively little on psoas. METHOD: Fifty consecutive patients presenting to a back pain triage clinic with unilateral low back pain lasting more than 12 weeks were recruited. The cross-sectional surface area (CSA) of the muscles was measured. Duration of symptoms, rating of pain, self-reported function, and the presence of neural compression were recorded. RESULTS: Data analysis compared the CSA between the symptomatic and asymptomatic sides. There was a statistically significant difference in CSA between the sides (P < 0.001). There was a positive correlation between the percentage decrease in CSA of psoas on the affected side and with the rating of pain (rho = 0.608, P < 0.01), reported nerve root compression (rho = 0.812, P < 0.01), and the duration of symptoms (rho = 0.886, P < 0.01). There was an association between decrease in the CSA of multifidus and duration of symptoms. CONCLUSIONS: Atrophy of multifidus has been used as one of the rationales for spine stabilization exercises. The evidence of coexisting atrophy of psoas and multifidus suggests that a future area for study should be selective exercise training of psoas, which is less commonly used in clinical practice.

Comment: Psoas muscle dysfunction has been suggested as a major contributor to many cases of low back pain. Successful treatment of the psoas muscle dysfunction is critical to the resolution of low back pain in these cases.

The efficiency of spinal manipulation in otorhinolaryngology. A retrospective long-term study, Hulse M, Holzl M.

HNO. 2004 Mar;52(3):227-34.

BACKGROUND: The vertebral genesis of many functional disorders in otorhinolaryngology, such as dizziness, hearing-impairment, ear-pressure, ear-pain, foreign body sensation in the throat and dysphonia, is suggested by the success of spinal manipulative therapy, particularly of the atlanto-occipital joint. Up to now, there are no retrospective investigations which show the duration of the therapeutic effect. METHODS: We examined 220 patients with cervical otorhinolaryngological disorders (100 patients with dizziness, 49 with hearing impairment, 47 with tinnitus and 24 with dysphonia) after cervical manipulation lasting more than 6 months. RESULTS AND CONCLUSIONS: The extraordinary satisfaction with the manipulative therapy in 82% of patients with dizziness (46% total relief, 36% high improvement) reflects the high efficiency of this manual therapy. In contrast to these results, only 10% of patients with tinnitus showed an improvement (P<0.001). This retrospective investigation demonstrates that a successful outcome after manual therapy is not based on a "placebo effect".

An exploratory study of provocation testing with padded wedges: can prone blocking demonstrate a directional preference? Lisi AJ, Cooperstein R, Morschhauser E.

J Manipulative Physiol Ther. 2004 Feb;27(2):103-8

BACKGROUND: Currently, no traditional chiropractic examination method to determine a spinal listing offers demonstrated guidance in treatment decisions for low back pain (LBP) patients. Development of an examination that bypasses the difficulty of accurately and reliably identifying a listing, yet provides guidance on manipulative vectors, could be very valuable to clinicians and patients. OBJECTIVE: To explore 2 potential protocols for provocation testing and assessment of directional preference using padded wedges. METHODS: Two groups of 20 subjects were examined while lying prone on various positions of padded wedges. In the first group, pain pressure threshold (PPT) was measured at 4 anatomic points; in the second group, tenderness was measured at 1 anatomic point. We investigated whether either method could demonstrate a directional preference response. RESULTS: When tenderness was measured at 1 anatomic point, 70% of subjects demonstrated a directional response, and only 1 subject exhibited an increase in baseline tenderness at the end of the procedure. When PPT was measured at 4 anatomic points, 40% of subjects demonstrated a directional response, but 12 subjects exhibited decreased PPT at the end of the procedure. CONCLUSION: Measuring changes in tenderness at 1 anatomic point in response to various padded wedge patterns appears promising as an examination procedure to determine directional preference.

Comment: The category system of analysis was developed by DeJarnette and expanded by Goodheart. This system organizes patterns of various possible bodily distortions, particularly the disturbances that occur in the sacroiliac and lumbosacral regions.  Briefly, Category I relates to imbalance or torque at the anterior aspect of the sacroiliac junction and its affect on meningeal balance and CSF fluctuation.  Category II is associated with various degrees of posterior sacroiliac joint ligamentous sprain and trauma.  A Category III condition will occur when the pelvis can no longer maintain weight-bearing capacity and shifts the "burden" to the lumbosacral junction with resultant discopathy and radiculopathy. These pelvic distortions produce reciprocal distortions throughout the body, especially in the pectoral girdle and first rib heads, the TMJ, the cervical spine, and the skull. Many muscle groups will be involved in the compensations a body makes to these pelvic category distortions.

A comparison of muscle strength testing techniques in amyotrophic lateral sclerosis,

Great Lakes ALS Study Group.

Neurology. 2003 Dec 9;61(11):1503-7.

OBJECTIVE: To assess the reliability of strength testing techniques among centers investigating patients with amyotrophic lateral sclerosis. METHODS: The authors compared test reliability in manual muscle testing (MMT) and maximal voluntary isometric contraction (MVIC) scores among institutions and test validity by comparing change over time between MMT and MVIC. The authors examined 63 subjects at 3-month intervals for 12 months. At enrollment and at 6 months, two physical therapists each examined the subjects twice. MMT scores were calculated as modifications of the Medical Research Council scale. MVIC scores were generated as standardized megascores. Intraclass correlation coefficients and coefficients of variation compared reproducibility, and Pearson correlation coefficients compared change over time. The power of each measure to detect disease progression over time was assessed by estimating coefficients of variation for the average change. RESULTS: Reproducibility between MVIC and MMT was equivalent. Sensitivity to detect progressive weakness and power to detect this change, however, favored MMT, an effect largely accounted for by the number of muscles sampled. CONCLUSIONS: In multicentered trials, uniformly trained physical therapists reproducibly and accurately measure strength by both MMT and MVIC. The authors found MMT to be the preferred measure of global strength because of its better Pearson correlation coefficients, essentially equivalent reproducibility, and more favorable coefficient of variation.

Comment: This paper is very important in understanding the clinical value (validity) of MMT in patients with neurologic disorders. It demonstrates that MMT is a more sensitive, more reliable and valid measure of dysfunction in patients with ALS than MVIC, which is another common method of muscle function evaluation.

Development of motor system dysfunction following whiplash injury, Sterling M, Jull G, Vicenzino B, Kenardy J, Darnell R.

Pain. 2003 May;103(1-2):65-73.

Abstract: Dysfunction in the motor system is a feature of persistent whiplash associated disorders. Little is known about motor dysfunction in the early stages following injury and of its progress in those persons who recover and those who develop persistent symptoms. This study measured prospectively, motor system function (cervical range of movement (ROM), joint position error (JPE) and activity of the superficial neck flexors (EMG) during a test of cranio-cervical flexion) as well as a measure of fear of re-injury (TAMPA) in 66 whiplash subjects within 1 month of injury and then 2 and 3 months post injury. Subjects were classified at 3 months post injury using scores on the neck disability index: recovered (<8), mild pain and disability (10-28) or moderate/severe pain and disability (>30). Motor system function was also measured in 20 control subjects. All whiplash groups demonstrated decreased ROM and increased EMG (compared to controls) at 1 month post injury. This deficit persisted in the group with moderate/severe symptoms but returned to within normal limits in those who had recovered or reported persistent mild pain at 3 months. Increased EMG persisted for 3 months in all whiplash groups. Only the moderate/severe group showed greater JPE, within 1 month of injury, which remained unchanged at 3 months. TAMPA scores of the moderate/severe group were higher than those of the other two groups. The differences in TAMPA did not impact on ROM, EMG or JPE. This study identifies, for the first time, deficits in the motor system, as early as 1 month post whiplash injury, that persisted not only in those reporting moderate/severe symptoms at 3 months but also in subjects who recovered and those with persistent mild symptoms.

Comment: Patients who have experienced cervical trauma from whiplash dynamics often have perplexing symptoms. The standard orthopedic and neurologic examination often does not find a cause for the bizarre symptoms about which some patients complain. Manual muscle testing is a method for evaluating the function of the nervous system; it often reveals the cause, giving an understanding of the patient's many complaints.Failure to recognize problems in the motor system in whiplash patients, and failure to correct it is often the reason a patient is labeled as being a malingerer or having a psychoneurotic overlay to his condition, and is one of the reasons why symptoms from whiplash injuries can persist for many years.

Neck muscle fatigue affects postural control in man, Schieppati M, Nardone A, and Schmid M.

Neuroscience, 2003;121(2):277-285.

Abstract: We hypothesized that, since anomalous neck proprioceptive input can produce perturbing effects on posture, neck muscle fatigue could alter body balance control through a mechanism connected to fatigue-induced afferent inflow. Eighteen normal subjects underwent fatiguing contractions of head extensor muscles. Sway during quiet stance was recorded by a dynamometric platform, both prior to and after fatigue and recovery, with eyes open and eyes closed. After each trial, subjects were asked to rate their postural control. Fatigue was induced by having subjects stand upright and exert a force corresponding to about 35% of maximal voluntary effort against a device exerting a head-flexor torque. The first fatiguing period lasted 5 min (F1). After a 5-min recovery period (R1), a second period of fatiguing contraction (F2) and a second period of recovery (R2) followed. Surface EMG activity from dorsal neck muscles was recorded during the contractions and quiet stance trials. EMG median frequency progressively decreased and EMG amplitude progressively increased during fatiguing contractions, demonstrating that muscle fatigue occurred. After F1, subjects swayed to a larger extent compared with control conditions, recovering after R1. Similar findings were obtained after F2 and after R2. Although such behavior was detectable under both visual conditions, the effects of fatigue reached significance only without vision. Subjective scores of postural control diminished when sway increased, but diminished more, for equal body sway, after fatigue and recovery. Contractions of the same duration, but not inducing EMG signs of fatigue, had much less influence on body sway or subjective scoring. We argue that neck muscle fatigue affects mechanisms of postural control by producing abnormal sensory input to the CNS and a lasting sense of instability. Vision is able to overcome the disturbing effects connected with neck muscle fatigue.

Myoelectric manifestations of sternocleidomastoid and anterior scalene muscle fatigue in chronic neck pain patients, Falla D, Rainoldi A, Merletti R, Jull G.

Clin Neurophysiol. 2003 Mar;114(3):488-95.

OBJECTIVE: This study compares myoelectric manifestations of fatigue of the sternocleidomastoid (SCM) and anterior scalene (AS) muscles between 10 chronic neck pain subjects and 10 normal matched controls. METHODS: Surface electromyography (sEMG) signals were recorded from the sternal head of SCM and AS muscles bilaterally during sub-maximal isometric cervical flexion contractions at 25 and 50% of the maximum voluntary contraction (MVC). The mean frequency, average rectified value and conduction velocity of the sEMG signal were calculated to quantify myoelectric manifestations of muscle fatigue. RESULTS: For both the SCM and AS muscles, the Mann-Whitney U test indicated that the initial value and slope of the mean frequency in neck pain patients were greater than in healthy subjects (P < 0.05). This was significant both at 25 and 50% of MVC. CONCLUSIONS: These results suggest: (a) a predominance of type-II fibres in the neck pain patients and/or (b) greater fatigability of the superficial cervical flexors in neck pain patients. These results are in agreement with previous muscle biopsy studies in subjects with neck pain, which identified transformation of slow-twitch type-1 fibres to fast-twitch type-IIB fibres, as well as the clinical observation of reduced endurance in the cervical flexors in neck pain patients.

Association of widespread body pain with an increased risk of cancer and reduced cancer survival: a prospective, population-based study, McBeth J, Silman AJ, Macfarlane GJ

Arthritis Rheum. 2003 Jun;48(6):1686-92.

OBJECTIVE: To determine whether reported widespread body pain is related to an increased incidence of cancer and/or reduced survival from cancer, since our previous population surveys have demonstrated a relationship between widespread body pain and a subsequent 2-fold increase in mortality from cancer over an 8-year period. METHODS: A total of 6565 subjects in Northwest England participated in 2 health surveys during 1991-1992. The subjects were classified according to their reported pain status (no pain, regional pain, and widespread pain), and were subsequently followed up prospectively until December 31, 1999. During follow up, information was collected on incidence of cancer and survival rates among those developing cancer. Associations between the original pain status and development of cancer and cancer survival were expressed as the incidence rate ratio (IRR) and mortality rate ratio (MRR), respectively. All analyses were adjusted for age, sex, and study location, the latter being a proxy measure of socioeconomic status. RESULTS: Among the study population, 6331 had never been diagnosed with cancer at the time of participation in the survey. Of these subjects, 956 (15%) were classified as having widespread pain, 3061 (48%) as having regional pain, and 2314 (37%) as having no pain. There were a total of 395 first malignancies recorded during follow up. In comparison with subjects reporting no pain, those with regional pain (IRR 1.19, 95% confidence interval [95% CI] 0.94-1.50) and widespread pain (IRR 1.61, 95% CI 1.21-2.13) experienced an excess incidence of cancer during the follow up period. The increased incidence among subjects previously reporting widespread pain was related, most strongly, to breast cancer (IRR 3.67, 95% CI 1.39-9.68), but there were also cancers of the prostate (IRR 3.46, 95% CI 1.25-9.59), large bowel (IRR 2.35, 95% CI 0.96-5.77), and lung (IRR 2.04, 95% CI 0.96-4.34). Subjects reporting widespread pain who subsequently developed cancer, in comparison with those previously reporting no pain, had an increased risk of death (MRR 1.82, 95% CI 1.18-2.80). This decreased survival was highest among subjects with cancers of the breast and prostate, although the effects on site-specific survival were nonsignificant. CONCLUSION: This study has demonstrated that widespread pain reported in population surveys is associated with a substantial subsequent increased incidence of cancer and reduced cancer survival. At present there are no satisfactory biologic explanations for this observation, although several possible leads have been identified.

Comment: The importance of this study is that patients with spinal injuries that lead to aberrant afferent mechanical input into the spinal cord, ultimately resulting in chronic back pain, may face a statistically significant increase in death rates from cancer.

The use of osteopathic manipulative treatment as adjuvant therapy in children with recurrent acute otitis media, Mills MV, Henley CE, Barnes LL, Carreiro JE, Degenhardt BF.

Arch Pediatr Adolesc Med. 2003 Sep;157(9):861-6.

OBJECTIVE: To study effects of osteopathic manipulative treatment as an adjuvant therapy to routine pediatric care in children with recurrent acute otitis media (AOM). STUDY DESIGN: Patients 6 months to 6 years old with 3 episodes of AOM in the previous 6 months, or 4 in the previous year, who were not already surgical candidates were placed randomly into 2 groups: one receiving routine pediatric care, the other receiving routine care plus osteopathic manipulative treatment. Both groups received an equal number of study encounters to monitor behavior and obtain tympanograms. Clinical status was monitored with review of pediatric records. The pediatrician was blinded to patient group and study outcomes, and the osteopathic physician was blinded to patient clinical course. MAIN OUTCOME MEASURES: We monitored frequency of episodes of AOM, antibiotic use, surgical interventions, various behaviors, and tympanometric and audiometric performance. RESULTS: A total of 57 patients, 25 intervention patients and 32 control patients, met criteria and completed the study. Adjusting for the baseline frequency before study entry, intervention patients had fewer episodes of AOM (mean group difference per month, -0.14 [95% confidence interval, -0.27 to 0.00]; P =.04), fewer surgical procedures (intervention patients, 1; control patients, 8; P =.03), and more mean surgery-free months (intervention patients, 6.00; control patients, 5.25; P =.01). Baseline and final tympanograms obtained by the audiologist showed an increased frequency of more normal tympanogram types in the intervention group, with an adjusted mean group difference of 0.55 (95% confidence interval, 0.08 to 1.02; P =.02). No adverse reactions were reported. CONCLUSIONS: The results of this study suggest a potential benefit of osteopathic manipulative treatment as adjuvant therapy in children with recurrent AOM; it may prevent or decrease surgical intervention or antibiotic overuse.

Presence of Chapman reflex points in hospitalized patients with pneumonia,
Washington K, Mosiello R, Venditto M, Simelaro J, Coughlin P, Crow WT, Nicholas A.

J Am Osteopath Assoc. 2003 Oct;103(10):479-83.

Abstract: The authors undertook a case control study to determine whether hospitalized patients with pneumonia had reflex points in the anterior chest wall as described by Frank Chapman, DO, specifically those classified as relating to the lung. Sixty-nine hospitalized patients were enrolled in the study. Patients with an admitting diagnosis of pneumonia were compared to those without pneumonia as their admitting diagnosis. All patie