New Concepts In Craniomandibular and chronic pain management, Edited by Harold Gelb. Chapter 15: Applied Kinesiology and the Stomatognathic System, Walther, D.S.
Mosby-Wolfe, London, 1994:349-368
Healers on Healing, Edited by Carlson, R., Shield, B. Innate Intelligence Is The Healer, Goodheart, G.
Jeremy P. Tarcher, Los Angeles; 1989:53-57
The Dental Clinics of North America: Symposium on Temporomandibular Joint Dysfunction and Treatment, Edited by Harold Gelb, D.M.D. Chapter 13: Applied Kinesiology in Dysfunction of the Temporomandibular Joint, Goodheart, G.
of a method of muscle testing, Lovett RW, Martin EG.
JAMA.1916 Mar 4; LXVI(10):729-33.
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.
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  vs. 63 ). 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.
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.
Cranial and Other Chiropractic Adjustments in the Conservative Treatment of Chronic Trigeminal Neuralgia: A Case Report, Pederick, F.
Chiro J Aust, 2005; 35:9-15.
ABSTRACT: Trigeminal neuralgia, sometimes called tic douloureux, is characterized by episodes of electric-shock-like pain in areas of the face where branches of the trigeminal nerve are distributed. Medical treatment includes pharmaceuticals, analgesics, surgery, radiosurgery, low-powered lasers, TENS, acupuncture and biofeedback. Manipulative approaches have been used successfully in a medical center in China, and reports of successful treatment with chiropractic techniques have been published. The patient in this report had a history of right-sided facial pain, diagnosed as trigeminal neuralgia, over a 6-year period with remissions after dental or medical treatment and exacerbations, the most recent of 2 months duration. Prior to cranial and other chiropractic adjustments, the patient had continuous pain that she rated at 9.5 on the visual analogue scale, and after 4 consultations over an 11-day period, pain had reduced to 0.5. Spinal and cranial adjusting potentially affects a wide range of causes of trigeminal neuralgia and offers a conservative, low-cost, low technology initial approach which, if ineffective, will not greatly delay or inhibit other treatment. Occasional maintenance care may be required in some instances to reduce occurrences.
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: 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.
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.
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.
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.
Treatment of an Infant with Wry Neck Associated with Birth Trauma: Case Report, Pederick, F.
Chiro J Aust, 2004; 34:123-8.
ABSTRACT: This paper describes the successful treatment of an infant with wry neck associated with birth trauma using low-force, relatively long-duration cranial adjusting, and soft-tissue techniques to the whole body with special attention to the cervical region, and parental management of home care procedures. Wry neck, or congenital muscular torticollis (CMT), has been a well-recognized condition for centuries. CMT is often associated with plagiocephaly, which has long-term adverse effects on physical and mental functions. A review of some of the literature relating to this condition is provided.
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 and abnormal 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.
Neck muscle fatigue affects postural control in man, Schieppati M, Nardone A, and Schmid M.
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.
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.
Do cerebral potentials to magnetic stimulation of paraspinal muscles reflect changes in palpable muscle spasm, low back pain, and activity scores? Zhu Y, Haldeman S, Hsieh CY, Wu P, Starr A.
J Manipulative Physiol Ther. 2002 Jan;25(1):77-8.
OBJECTIVE: Previous studies have shown that cortical-evoked potentials on magnetic stimulation of muscles are influenced by muscle contraction, vibration, and muscle spasm. This study was carried out to determine whether these potentials correlate with palpatory muscle spasm, patient symptoms, and disability in patients with low back pain. METHODS: A prospective observational study was performed on 13 subjects with a history of low back pain visiting an orthopedic hospital-based clinic. Patients were screened for serious pathologic conditions by an orthopedic surgeon. The patients were then evaluated for the presence of muscle spasm by one of the investigators who was blinded to the results of the evoked potential studies. Patients were asked to complete a low back pain visual analogue scale (VAS) and a Roland-Morris Activity Scale (RMAS). Cortical-evoked potentials were recorded with a magnetic stimulator placed over the lumbar paraspinal muscles with the patient in the prone position. The palpatory examination, VAS, RMAS, and the cortical potentials were repeated after 2 weeks of therapy commonly used to reduce muscle spasm. RESULTS: The patients demonstrated a significant decrease in low back pain VAS and RMAS scores after treatment compared with before treatment. There was a reduction in the amount of palpatory muscle spasm in 11 of 13 cases. The cortical potentials before treatment were attenuated compared with previously reported controls and showed a significant increase before and after treatment in the amplitude of these potentials with multivariate analysis of variance. There was significant correlation between the changes in cortical potentials after treatment and the changes noted in paraspinal muscle spasm and VAS and RMAS scores. CONCLUSIONS: This study confirms the previous report that the amplitude of cerebral-evoked potentials on magnetic stimulation of paraspinal muscles is depressed in the presence of palpable muscle spasm. The close correlation among these potentials, paraspinal muscle spasm, and clinical symptoms suggests that the measurement of muscle activity may be more important in the assessment of low back pain than is commonly accepted.
Comment: This hypothesis has been made in AK since the technique was founded. Through evaluation of the function of certain muscles pre- and post-treatment, therapeutic efficacy for particular problems can be evaluated. Applied kinesiologists theorize that physical, chemical, and mental imbalances are associated with secondary muscle dysfunction – specifically a muscle inhibition (usually preceding an overfacilitation of an opposing muscle). Applying the proper therapy results in improvement in the inhibited muscle. This study demonstrates the simultaneous presence of muscle spasm and depressed cortical-evoked potentials in patients with low back pain. After 2 weeks of chiropractic spinal therapy the patients were alleviated of their clinical symptoms and increased the synaptic efficacy of Ia afferent activation to the central nervous system.
Central motor excitability changes after spinal manipulation: A transcranial magnetic stimulation study, Dishman J, Ball K, Burke J.
J Manipulative Physiol Ther 2002;25:1-9
Background: The physiologic mechanism by which spinal manipulation may reduce pain and muscular spasm is not fully understood. One such mechanistic theory proposed is that spinal manipulation may intervene in the cycle of pain and spasm by affecting the resting excitability of the motoneuron pool in the spinal cord. Previous data from our laboratory indicate that spinal manipulation leads to attenuation of the excitability of the motor neuron pool when assessed by means of peripheral nerve Ia-afferent stimulation (Hoffmann reflex). Objective: The purpose of this study was to determine the effects of lumbar spinal manipulation on the excitability of the motor neuron pool as assessed by means of transcranial magnetic stimulation. Methods: Motor-evoked potentials were recorded subsequent to transcranial magnetic stimulation. The motor-evoked potential peak-to-peak amplitudes in the right gastrocnemius muscle of healthy volunteers (n = 24) were measured before and after homolateral L5-S1 spinal manipulation (experimental group) or side-posture positioning with no manipulative thrust applied (control group). Immediately after the group-specific procedure, and again at 5 and 10 minutes after the procedure, 10 motor-evoked potential responses were measured at a rate of 0.05 Hz. An optical tracking system (OptoTRAK, Northern Digital Inc, Waterloo, Canada [<0.10 mm root-mean-square]) was used to monitor the 3-dimensional (3-D) position and orientation of the transcranial magnetic stimulation coil, in real time, for each trial. Results: The amplitudes of the motor-evoked potentials were significantly facilitated from 20 to 60 seconds relative to the pre baseline value after L5-S1 spinal manipulation, without a concomitant change after the positioning (control) procedure. Conclusions: When motor neuron pool excitability is measured directly by central corticospinal activation with transcranial magnetic stimulation techniques, a transient but significant facilitation occurs as a consequence of spinal manipulation. Thus, a basic neurophysiologic response to spinal manipulation is central motor facilitation.
Assessment of isokinetic muscle strength in women who are obese, Hulens M, Vansant G, Lysens R, Claessens AL, Muls E.
-- Department of Rehabilitation Sciences, Faculty of Physical Education and Physiotherapy, Katholieke Universiteit, Leuven, Belgium. email@example.com
J Orthop Sports Phys Ther. 2002 Jul;32(7):347-56.
STUDY DESIGN: Cross-sectional study of isokinetic trunk and knee muscle strength in women who are obese. OBJECTIVE: To provide reference values, to identify variables that affect peripheral muscle strength, and to provide recommendations for isokinetic testing of trunk and knee muscles in women who are obese and morbidly obese. BACKGROUND: The assessment of peripheral muscle strength is useful for the quantification of possible loss of strength, for exercise prescription, and for the evaluation of the effect of training programs in obese individuals. METHODS AND MEASURES: Isokinetic trunk and leg muscle strength was assessed in 241 women who were obese (18-65 years, body mass index (BMI) > or = 30 kg/m2). Trunk flexion and extension peak torque (PT) was measured using the Cybex TEF dynamometer; trunk rotation (TR) PT was measured using the Cybex TORSO dynamometer; and knee flexion/extension (KFE) PT was measured using the Cybex 350 dynamometer. Body composition was assessed using the bioelectrical impedance method; physical activity was assessed using the Baecke questionnaire; and peak VO2 was assessed using an incremental exercise capacity test on a bicycle ergometer. To identify variables related to muscle strength, Pearson correlations were computed and a stepwise multiple regression analysis was performed. RESULTS: Pearson correlation coefficients of all strength measurements at 60 degrees/s revealed low-to-moderate negative associations with age and positive associations with mass, height, fat free mass (FFM), and peak VO2 (P < 0.05), except for gravity-uncorrected trunk extension strength, which was not related to mass. The sports index of the Baecke questionnaire was associated with TR PT (r = 0.20, P < 0.01) and KFE PT (r = 0.18, P < 0.05). CONCLUSION: The weight of the trunk accounts largely for the measured trunk extensor and flexor strength in women who are obese. Contributing variables of isokinetic trunk flexion and extension strength in women who are obese are age, height, and FFM; whereas sports activities and aerobic fitness are contributing factors for trunk rotational and knee extension strength. Recommendations for measuring isokinetic muscle strength in individuals who are obese are provided.
The reliability of upper- and lower-extremity strength testing in a community survey of older adults, Ottenbacher KJ, Branch LG, Ray L, Gonzales VA, Peek MK, Hinman MR.
-- Division of Rehabilitation Sciences, Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX 77555-1028, USA. firstname.lastname@example.org
Arch Phys Med Rehabil. 2002 Oct;83(10):1423-7.
OBJECTIVE: To examine the stability (test-retest reliability) of strength measures in older adults obtained by nontherapist lay examiners by using a hand-held portable muscle testing device (Nicholas Manual Muscle Tester). DESIGN: A prospective relational design was used to collect test-retest data for 1 male subject by using 27 lay raters who completed intensive training in manual muscle. SETTING: Data were collected from older Mexican-American adults living in the community.