PARTICIPANTS: Twenty-seven lay raters who completed intensive training in manual muscle testing for a field-based assessment and interview of older adults and 63 Mexican-American subjects completing wave 4 of the Hispanic Established Populations for the Epidemiologic Study of the Elderly. INTERVENTIONS: Training involved reviewing a manual describing each testing position followed by approximately 6 hours of instruction and practice supervised by an experienced physical therapist. Lay raters then collected test-retest information on older Mexican-American subjects. MAIN OUTCOME MEASURE: Stability (test-retest) for a portable manual muscle testing device. RESULTS: Intraclass correlation coefficients (ICCs) were computed for the 27 lay raters examining 1 male subject (2 trials) and 12 lay raters assessing 63 older Mexican-American adults (1 practice and 2 trials recorded). The ICC values for the first 27 lay raters ranged from .74 to.96. The ICC values for the latter 12 lay raters ranged from .87 to.98. No differences were found in ICC values between male or female subjects. CONCLUSIONS: Stable and consistent information for upper- and lower-extremity strength was collected from the older adults participating in this study. The results suggest reliable information can be obtained by lay raters using a portable manual muscle testing device if the examiners receive intensive training.
A retrospective study of cranial strain patterns in patients with idiopathic Parkinson’s disease, Rivera-Martinez, S., Wells, M., Capobianco, J.
Journal of the American Osteopathic Association, August 2002;102(8):417-422
Abstract: While providing osteopathic manipulative treatment to patientswith Parkinson's disease at the clinic of the New York Collegeof Osteopathic Medicine of New York Institute of Technology,physicians noted that these patients may exhibit particularcranial findings as a result of the disease. The purpose ofthis study was to compare the recorded observations of cranialstrain patterns of patients with Parkinson's disease for thedetection of common cranial findings. Records of cranial strainpatterns from physician-recorded observations of 30 patientswith idiopathic Parkinson's disease and 20 age-matched normalcontrols were compiled. This information was used to determinewhether different physicians observed particular strain patternsin greater frequency between Parkinson's patients and controls.Patients with Parkinson's disease had a significantly higherfrequency of bilateral occipitoatlantal compression (87% vs.50%; P < .02) and bilateral occipitomastoid compression (40% vs. 10%; P < .05) compared with normal controls. Over subsequent visits and treatments, the frequency of both strain patterns were reduced significantly (occipitoatlantal compression, P < .01; occipitomastoid compression, P < .05) to levels found in the control group.
Radiographic Evidence of Cranial Bone Mobility, Oleski, S, Smith G, Crow W
Cranio: The Journal of Craniomandibular Practice; Jan 2002;20(1):34-8
The purpose of this retrospective chart review was to determine if external manipulation of the cranium alters selected parameters of the cranial vault and base that can be visualized and measured on x-ray. Twelve adult patient charts were randomly selected to include patients who had received cranial vault manipulation treatment with a pre- and post-treatment x-ray taken with the head in a fixed positioning device. The degree of change in angle between various specified cranial landmarks as visualized on x-ray was measured. The mean angle of change measured at the atlas was 2.58 degrees, at the mastoid was 1.66 degrees, at the malar line was 1.25 degrees, at the sphenoid was 2.42 degrees, and at the temporal line was 1.75 degrees. 91.6% of patients exhibited differences in measurement at three or more sites. This study concludes that cranial bone mobility can be documented and measured on x-ray.
Sensorimotor control of the spine, Holm, S., Indahl, A., Solomonow, M.
Journal of Electromyography and Kinesiology, 2002,12;3:219-234.
Abstract: The spinal viscoelastic structures including disk, capsule and ligaments were reviewed with special focus on their sensory motor functions. Afferent capable of monitoring proprioceptive and kinesthetic information are abundant in the disc, capsule and ligament. Electrical stimulation of the lumbar afferents in the discs, capsules and ligaments seem to elicit reflex contraction of the multifidus and also longissimus muscles. The muscular excitation is pronounced in the level of excitation and with weaker radiation 1 to 2 levels above and below. Similarly, mechanical stimulation of the spinal viscoelastic tissues excites the muscles with higher excitation intensity when more than one tissue (ligaments and discs for example) is stimulated. Overall, it seems that spinal structures are well suited to monitor sensory information as well as to control spinal muscles and probably also provide kinesthetic perception to the sensory cortex.
Comment: The new and strikingly original feature of AK is that it brings together in a functional, inseparable manner the spinal, the nervous, and the muscle systems. Remarkably, each system demonstrates and maintains the condition of the other.
Electromyographic reflex response to mechanical force, manually-assisted spinal manipulative therapy, Colloca, C.J., Keller, T.S.
Study Design: Surface electromyographic reflex responses associated with mechanical force, manually assisted (MFMA) spinal manipulative therapy were analyzed in this prospective clinical investigation of 20 consecutive patients with low back pain.
Objectives: To characterize and determine the magnitude of electromyographic reflex responses in human paraspinal muscles during high loading rate mechanical force, manually assisted spinal manipulative therapy of the thoracolumbar spine and sacroiliac joints. Summary of Background Data: Spinal manipulative therapy has been investigated for its effectiveness in the treatment of patients with low back pain, but its physiologic mechanisms are not well understood. Noteworthy is the fact that spinal manipulative therapy has been demonstrated to produce consistent reflex responses in the back musculature; however, no study has examined the extent of reflex responses in patients with low back pain. Methods: Twenty patients (10 male and 10 female, mean age 43.0 years) underwent standard physical examination on presentation to an outpatient chiropractic clinic. After repeated isometric trunk extension strength tests, short duration (<5 msec), localized posteroanterior manipulative thrusts were delivered to the sacroiliac joints, and L5, L4, L2, T12, and T8 spinous processes and transverse processes. Surface, linear-enveloped electromyographic (sEMG) recordings were obtained from electrodes located bilaterally over the L5 and L3 erector spinae musculature. Force-time and sEMG time histories were recorded simultaneously to quantify the association between spinal manipulative therapy mechanical and electromyographic response. A total of 1600 sEMG recordings were analyzed from 20 spinal manipulative therapy treatments, and comparisons were made between segmental level, segmental contact point (spinous vs. transverse processes), and magnitude of the reflex response (peak-peak [p-p] ratio and relative mean sEMG). Positive sEMG responses were defined as >2.5 p-p baseline sEMG output (>3.5% relative mean sEMG output). SEMG threshold was further assessed for correlation of patient self-reported pain and disability. Results: Consistent, but relatively localized, reflex responses occurred in response to the localized, brief duration MFMA thrusts delivered to the thoracolumbar spine and SI joints. The time to peak tension (sEMG magnitude) ranged from 50 to 200 msec, and the reflex response times ranged from 2 to 4 msec, the latter consistent with intraspinal conduction times. Overall, the 20 treatments produced systematic and significantly different L5 and L3 sEMG responses, particularly for thrusts delivered to the lumbosacral spine. Thrusts applied over the transverse processes produced more positive sEMG responses (25.4%) in comparison with thrusts applied over the spinous processes (20.6%). Left side thrusts and right side thrusts over the transverse processes elicited positive contralateral L5 and L3 sEMG responses. When the data were examined across both treatment level and electrode site (L5 or L3, L or R), 95% of patients showed positive sEMG response to MFMA thrusts. Patients with frequent to constant low back pain symptoms tended to have a more marked sEMG response in comparison with patients with occasional to intermittent low back pain. Conclusions: This is the first study demonstrating neuromuscular reflex responses associated with MFMA spinal manipulative therapy in patients with low back pain. Noteworthy was the finding that such mechanical stimulation of both the paraspinal musculature (transverse processes) and spinous processes produced consistent, generally localized sEMG responses. Identification of neuromuscular characteristics, together with a comprehensive assessment of patient clinical status, may provide for clarification of the significance of spinal manipulative therapy in eliciting putative conservative therapeutic benefits in patients with pain of musculoskeletal origin.
Sensory motor control of the lower back: implications for rehabilitation, Ebenbichler, G, Oddsson, L, Kollmitzer, J, Erim, Z.
Med Sci Sports Exer, 2001;33:1889-98
This paper described a series of studies that have been done investigating the surface electromyography (SEMG) fatigue pattern of the back muscles during submaximal contraction. SEMG changes correlated with erector muscle fatigue, validating the subjective erector muscle endurance tests against the objective SEMG. Given the results of this study, a larger double-blind study of SEMG evaluation compared to manual muscle testing could be done, wherein back muscles strength and endurance time during testing are measured before and after a course of chiropractic care.
Ischemia causes muscle fatigue, Murthy, G, Hargens, A, Lehman, S, Rempel, D.
J Orthop Res, 2001;19:436-440
The purpose of this investigation was to determine whether ischemia, which reduces oxygenation in the extensor carpi radialis (ECR) muscle, causes a reduction in muscle force production. In eight subjects, muscle oxygenation (TO2) of the right ECR was measured noninvasively and continuously using near infrared spectroscopy (NIRS) while muscle twitch force was elicited by transcutaneous electrical stimulation (1 Hz, 0.1 ms). Baseline measurements of blood volume, muscle oxygenation and twitch force were recorded continuously, then a tourniquet on the upper arm was inflated to one of five different pressure levels: 20, 40, 60 mm Hg (randomized order) and diastolic (69 ± 9.8 mm Hg) and systolic (106 ± 12.8 mm Hg) blood pressures. Each pressure level was maintained for 3–5 min, and was followed by a recovery period sufficient to allow measurements to return to baseline. For each respective tourniquet pressure level, mean TO2 decreased from resting baseline (100% TO2) to 99 ± 1.2% (SEM), 96 ± 1.9%, 93 ± 2.8%, 90 ± 2.5%, and 86 ± 2.7%, and mean twitch force decreased from resting baseline (100% force) to 99 ± 0.7% (SEM), 96 ± 2.7%, 93 ± 3.1%, 88 ± 3.2%, and 86 ± 2.6%. Muscle oxygenation and twitch force at 60 mm Hg tourniquet compression and above were significantly lower (P<0.05) than baseline value. Reduced twitch force was correlated in a dose-dependent manner with reduced muscle oxygenation (r=0.78,P<0.001). Although the correlation does not prove causation, the results indicate that ischemia leading to a 7% or greater reduction in muscle oxygenation causes decreased muscle force production in the forearm extensor muscle. Thus, ischemia associated with a modest decline in TO2 causes muscle fatigue.
Comparison of effects of spinal manipulation and massage on motoneuron excitability, Dishman J, Bulbulian R.
Electromyogr Clin Neurophysiol. 2001;41:97-106
Abstract: The purpose of this study was to compare the magnitude and duration of motoneuron inhibition occurring as a sequel to spinal manipulation or paraspinal and limb massage. The physiologic mechanisms involved in spinal manipulative therapy and massage therapy are largely unknown. One possible hypothesis is based upon the theory that these two distinct and different modalities may attenuate the activity of alpha motoneurons. Both modalities have been reported to produce short-term inhibition of motoneurons. Asymptomatic volunteers were randomly assigned to either a spinal manipulation, massage, or control group. Baseline tibial nerve H-reflex amplitudes were obtained prior to the application of either lumbosacral spinal manipulation or paralumbar and limb massage. Post-interventional H-reflex recordings were recorded immediately following the application of either modality. Spinal manipulation significantly (p < 0.05) attenuated alpha motoneuronal activity immediately post-therapy, as measured by the amplitude of the tibial nerve H-reflex. Massage subjects exhibited no significant reduction in motoneuronal activity immediately following administration. Spinal manipulation produced a transient attenuation of alpha motoneuronal excitability. Paraspinal and limb massage did not inhibit the motoneuron pool as measured immediately post-therapy. These findings support the supposition that spinal manipulation procedures lead to short-term inhibitory effects on motoneuron excitability to a greater magnitude than massage.
Measuring knee extensor muscle strength, Bohannon RW.
-- Department of Physical Therapy, School of Allied Health, University of Connecticut, Storrs 06269-2101, USA.
Am J Phys Med Rehabil. 2001 Jan;80(1):13-8.
OBJECTIVE: To compare manual muscle test with hand-held dynamometer measurements of knee extension strength. A secondary analysis of measurements (n = 256 knees) from 128 acute rehabilitation patients was performed. DESIGN: Knee extensor muscle testing was conducted according to the technique of Hislop and Montgomery; 0 to 5 grades were converted to an expanded 0 to 12 scale. Dynamometry was used to measure the isometric knee extension force with 'gravity eliminated.' RESULTS: Manual muscle test and dynamometer measures were highly correlated (r = 0.768; P < 0.001); the correlation was higher when the quadratic nature of the relationship was taken into account (R = 0.887; P < 0.001). Although the dynamometer forces that were associated with different manual muscle test grades differed overall (F = 67.736; P < 0.001), the forces associated with some of the higher grades did not differ statistically. CONCLUSIONS: These findings reinforce the convergent construct validity of the manual muscle test and dynamometry measurements but challenge the discriminant construct validity of manual muscle testing. An alternative manual muscle testing grading scheme is suggested that provides for discriminant validity and retains convergent validity.
The cytological implications of primary respiration, Crisera, P.
Medical Hypotheses, Jan 2001; 56(1):40-51
Abstract: Observing the macroscopic complexities of evolved species, the exceptional
continuity that occurs among different cells, tissues and organs to respond
coherently to the proper set of stimuli as a function of self/species
survival is appreciable. Accordingly, it alludes to a central rhythm that
resonates throughout the cell; nominated here as primary respiration (PR),
which is capable of binding and synchronizing a diversity of physiological
processes into a functional biological unity. Phylogenetically, it was
conserved as an indispensable element in the makeup of the subkingdom
Metazoan, since these species require a high degree of coordination among the different cells that form their body. However, it does not preclude the possibility of a basal rhythm to orchestrate the intricacies of cellular dynamics of both prokaryotic and eukaryotic cells. In all probability, PR emerges within the crucial organelles, with special emphasis on the DNA, and propagated and transduced within the infrastructure of the cytoskeleton as wave harmonics. Collectively, this equivalent vibration for the subphylum Vertebrata emanates as craniosacral respiration (CSR), though its expression is more elaborate depending on the development of the CNS. Furthermore, the author suggests that the phenomenon of PR or CSR be intimately associated to the basic rest/activity cycle (BRAC), generated by concentrically localized neurons that possess auto-oscillatory properties and assembled into a vital network. Historically, during Protochordate-Vertebrate transition, this area circumscribes an archaic region of the brain in which many vital biological rhythms have their source, called hindbrain rhombomeres. Bass and Baker propose that
pattern-generating circuits of more recent innovations, such as vocal, electromotor, extensor muscle tonicity, locomotion and the extraocular system, have their origin from the same Hox gene-specified compartments of the embryonic hindbrain (rhombomeres 7 and 8) that produce rhythmically active cardiac and thoracic respiratory circuits. Here, it implies that PR could have been the first essential biological cadence that arose with the earliest form of life, and has undergone a phylogenetic ascent to produce an integrated multirhythmic organism of today. Finally, in its full manifestation, the breathing DNA of the zygote could project itself throughout the cytoskeleton and modify the electromechanical properties of the plasma lamella, establishing the primordial axial-voltage gradients for the physiological control of development
Attachments from the Spinal Dura to the Ligamentum Nuchae: Incidence, MRI Appearance, and Strength of Attachment, Kenin S, Humphreys BK, Hubbard B, Cramer GD
Proceedings of the 2000 International Conference of Spinal Manipulation 2000;Sept:202-4
Abstract: The identification of attachments to the posterior spinal dura from the surrounding tissues in the cranio-cervical region by Von Lanz in 1929, may provide the key towards a better understanding of underlying mechanisms involved in chronic benign headaches as well as neck pain of unknown etiology. The recent findings of connective tissue attachments to the cervical spinal dura from muscles, ligament, and osseous elements have sparked increasing interest among clinicians and anatomists. However, studies of a large number of specimens or those evaluating the MRI appearance of these attachments have never been published. This study evaluated these attachments in 30 cadaveric spines and then correlated the MRI appearance of the attachments to their anatomic appearance on 4 of the specimens.
This study identified a consistent connective tissue complex arising from within the substance of the ligamentum nuchae, between the occiput and axis, giving rise to 3 connective tissue bridges. Two of the connective tissue bridges attached to the posterior spinal dura while the third linked the rectus capitis posterior minor muscle to the ligamentum nuchae. Of significance were: (1) The attachment between the ligamentum nuchae and dura between C1-C2 are quite robust. (2) The attachments between the rectus capitis posterior minor and ligamentum nuchae usually exist. (3) The attachments between the ligamentum nuchae and dura mater can be identified on MRI scans. These attachments may have clinical significance in cervicogenic headache, vertigo, and flexion-extension (whiplash) injuries, making their MRI appearance clinically important.
Conservative lower back treatment reduces inhibition in knee-extensor muscles: a randomized controlled trial,Suter, E., McMorland, G., Herzog, W., Bray, R.
J Manipulative Physiol Ther, 2000;23:76-80
Background: Knee-joint pathologies, such as anterior knee pain (AKP), are associated with strength deficits and reduced activation of the knee extensors, which is referred to as muscle inhibition (MI). MI is thought to prevent full functional recovery, and treatment modalities that help to reduce or eliminate MI appear necessary for successful rehabilitation. Clinical observations suggest that AKP is typically associated with sacroiliac (SI) joint dysfunction. It is unknown whether Sl-joint dysfunction contributes to knee-extensor deficits and whether correction of SI-joint dysfunction alleviates MI. Objective: The objective of this study was to assess whether conservative low back treatment reduces lower limb MI. Study design: In a randomized, controlled, double-blind study the effects of conservative lower back treatment on knee-extensor strength and MI were evaluated in patients with AKP. Methods: Twenty-eight patients with AKP were randomly assigned to either a treatment or a control group. After a lower back functional assessment, the treatment group received a conservative treatment in the form of a chiropractic spinal manipulation aimed at correcting SI-joint dysfunction. The control group underwent a lower back functional assessment but received no joint manipulation. Before and after the manipulation or the lower back functional assessment, knee-extensor moments, MI, and muscle activation during full effort, isometric knee extensions were measured. Results: Patients showed substantial MI in both legs. Functional assessment revealed SI-joint dysfunction in all subjects (23 symptomatic and 5 asymptomatic). After the SI-joint manipulation, a significant decrease in MI of 7.5% was observed in the involved legs of the treatment group. MI did not change in the contralateral legs of the treatment group or the involved and contralateral legs of the control group. There were no statistically significant changes in knee-extensor moments and muscle activation in either group. Conclusions: The results of this study suggest that SI-joint manipulation reduces knee-extensor MI. Spinal manipulation may possibly be an effective treatment of MI in the lower limb musculature.
Reflex effects of subluxation: the autonomic nervous system, Budgell, B.S.
J Manipulative Physiol Ther, 2000;23(2):104-106
Background: The collective experience of the chiropractic profession is that aberrant stimulation at a particular level of the spine may elicit a segmentally organized response, which may manifest itself in dysfunction within organs receiving autonomic innervation at that level. This experience is at odds with classic views of neuroscientists about the potential for somatic stimulation of spinal structures to affect visceral function. Objective: To review recent findings from basic physiologic research about the effects of somatic stimulation of spinal structures on autonomic nervous system activity and the function of dependent organs. Data source: Findings were drawn from a major recent review of the literature on the influences of somatic stimulation on autonomic function and from recent original physiologic studies concerning somatoautonomic and spinovisceral reflexes.
Conclusions: Recent neuroscience research supports a neurophysiologic rationale for the concept that aberrant stimulation of spinal or paraspinal structures may lead to segmentally organized reflex responses of the autonomic nervous system, which in turn may alter visceral function.
Abnormalities of the soleus H-reflex in lumbar spondylolisthesis: a possible early sign of bilateral S1 root dysfunction, Mazzocchio R, Scarfo GB, Cartolari R, Bolognini A, Mariottini A, Muzii VF, Palma L.
J Spinal Disord. 2000 Dec;13(6):487-95.
Abstract: Using routine electrodiagnostic procedures, the authors searched for physiologic evidence of nerve root compromise in patients with chronic mechanical perturbation to the lumbar spine. They examined 37 patients with spondylolisthesis and various degrees of degenerative changes in the lumbar canal. Clinical and neurophysiologic findings were compared with data obtained from 36 healthy persons. The soleus H-reflex appeared to be a sensitive indicator of sensory fiber compromise at the S1 root level, because changes correlated well with the focal sensory signs and preceded clinical and electromyographic signs of motor root involvement. When these occurred, the clinical findings were consistent with a more severe nerve root deficit and with radiographic evidence of neural compression. The greater sensitivity of the soleus H-reflex may be related to the pathophysiologic events that occur at the lesion site.
Spinal reflex attenuation associated with spinal manipulation, Dishman JD, Bulbulian R.
Spine, 2000 Oct 1;25(19):2519-24;discussion 2525.
STUDY DESIGN: This study evaluated the effect of lumbosacral spinal manipulation with thrust and spinal mobilization without thrust on the excitability of the alpha motoneuronal pool in human subjects without low back pain. OBJECTIVES: To investigate the effect of high velocity, low amplitude thrust, or mobilization without thrust on the excitability of the alpha motoneuron pool, and to elucidate potential mechanisms in which manual procedures may affect back muscle activity. SUMMARY OF BACKGROUND DATA: The physiologic mechanisms of spinal manipulation are largely unknown. It has been proposed that spinal manipulation may reduce back muscle electromyographic activity in patients with low back pain. Although positive outcomes of spinal manipulation intervention for low back pain have been reported in clinical trials, the mechanisms involved in the amelioration of symptoms are unknown. METHODS: In this study, 17 nonpatient human subjects were used to investigate the effect of spinal manipulation and mobilization on the amplitude of the tibial nerve Hoffmann reflex recorded from the gastrocnemius muscle. Reflexes were recorded before and after manual spinal procedures. RESULTS: Both spinal manipulation with thrust and mobilization without thrust significantly attenuated alpha motoneuronal activity, as measured by the amplitude of the gastrocnemius Hoffmann reflex. This suppression of motoneuronal activity was significant (P < 0.05) but transient, with a return to baseline values exhibited 30 seconds after intervention. CONCLUSIONS: Both spinal manipulation with thrust and mobilization without thrust procedures produce a profound but transient attenuation of alpha motoneuronal excitability. These findings substantiate the theory that manual spinal therapy procedures may lead to short-term inhibitory effects on the human motor system.
Comment: This study demonstrates that there is an immediate effect upon the motor system after spinal manipulative therapy. This factor has been consistently demonstrated in AK, and measuring the effect upon the motor system is made after every manipulative treatment. Clinical conditions involving hypotonicity, spasticity or hypertonicity are attributed to pathophysiologic abnormalities in the motor neuron system, and this study measures this state.
Integrated jaw and neck function in man. Studies of mandibular and head-neck movements during jaw opening-closing tasks, Zafar H
Swed Dent J Suppl, 2000;(143):1-41.
Abstract: This investigation was undertaken to test the hypothesis of a functional relationship between the human temporomandibular and craniocervical regions. Mandibular and head-neck movements were simultaneously recorded in healthy young adults using a wireless optoelectronic system for three dimensional movement recording. The subjects were seated in an upright position without head support and were instructed to perform maximal jaw opening-closing movements at fast and slow speed. As a basis, a study was undertaken to develop a method for recording and analysis of mandibular and head-neck movements during natural jaw function. A consistent finding was parallel and coordinated head-neck movements during both fast and slow jaw opening-closing movements. The head in general started to move simultaneously with or before the mandible at the initiation of jaw opening. Most often, the head attained maximum velocity after the mandible. A high degree of spatiotemporal consistency of mandibular and head-neck movement trajectories was found in successive recording sessions. The head movement amplitude and the temporal coordination between mandibular and head-neck movements were speed related but not the movement trajectory patterns. Examination of individuals suffering from temporomandibular disorders and whiplash associated disorders (WAD) showed, compared with healthy subjects, smaller amplitudes, a diverse pattern of temporal coordination but a similar high degree of spatiotemporal consistency for mandibular and head-neck movements. In conclusion, the results suggest the following: A functional linkage exists between the human temporomandibular and craniocervical regions. Head movements are an integral part of natural jaw opening-closing. "Functional jaw movements" comprise concomitant mandibular and head-neck movements which involve the temporomandibular, the atlanto-occipital and the cervical spine joints, caused by jointly activated jaw and neck muscles. Jaw and neck muscle actions are elicited and synchronized by neural commands in common for both the jaw and the neck motor systems. These commands are preprogrammed, particularly at fast speed. In the light of previous observations of concurrent jaw and head movements during foetal yawning, it is suggested that these motor programs are innate. Neural processes underlying integrated jaw and neck function are invariant both in short- and long-term perspectives. Integrated jaw and neck function seems to be crucial for maintaining optimal orientation of the gape in natural jaw function. Injury to the head-neck, leading to WAD may derange integrated jaw-neck motor control and compromise natural jaw function.
Comment: In AK examination and treatment, the complexity of the TMJ apparatus is recognized. The TMJ is part of a complex system including the bones of the skull and cervical spine, the mandible and hyoid bone, the related muscle attachments and other soft tissues, and neurologic and vascular components. This complex is often referred to as the stomatognathic system. The use of AK methods, especially challenge and therapy localization, greatly assists the practitioner in finding concealed or hidden TMJ problems.
EMG and strength correlates of selected shoulder muscles during rotations of the glenohumeral joint, David G, Magarey ME, Jones MA, Dvir Z, Turker KS, Sharpe M.
Clin Biomech (Bristol, Avon). 2000 Feb;15(2):95-102.
OBJECTIVE: To identify activation patterns of several muscles acting on the shoulder joint during isokinetic internal and external rotation. DESIGN: Combined EMG and isokinetic strength analysis in healthy subjects. BACKGROUND: EMG studies of the shoulder region revealed intricate muscular activation patterns during elevation of the arm but no parallel studies regarding pure rotations of the joint could be located. METHODS: Fifteen (n=30 shoulders) young, asymptomatic male subjects participated in the study. Strength production during isokinetic concentric and eccentric internal and external rotations at 60 and 180 degrees /s was correlated with the EMG activity of the rotator cuff, biceps, deltoid and pectoralis major. Analysis of the smoothed EMG related to the timing of onset of the signal and to the normalized activity at the angle of the peak moment. Determination of the association between the EMG and the moment was based on strength ratios. RESULTS: Findings indicated that for both types of rotations, the rotator cuff and biceps were active 0.092+/-0.038-0.215+/-0.045 s prior to the initiation of the actual movement and 0.112-0.034 s prior to onset of deltoid and pectoralis major activity. These differences were significant in all of the eight conditions (P<0.05). In terms of the strength ratios, strong association was found between electrical activity and moment production in the subscapularis and infraspinatus (r(2)=0.95 and 0. 72, respectively) at the low and high angular velocities. CONCLUSIONS: Prior to actual rotation of the shoulder joint, normal recruitment of the rotator cuff and biceps is characterized by a non-specific presetting phase which is mainly directed at enhancing the joint 'stiffness' and hence its stability. Once movement is in progress, the EMG patterns of these muscles become movement specific and are correlated with the resultant moment. RELEVANCE: Muscular dysfunction relating to delayed onset activity or altered activation patterns, due to pain, perturbed mechanics or disturbed neural activation have been implicated as concomitant factors in other joint associated pathologies. Through highlighting the role of the rotator cuff in shoulder joint rotations, this study lends further support to the argument that a parallel situation may prevail with respect to shoulder joint dysfunction. This could lead to the development of rehabilitation protocols aimed specifically at redressing such dysfunction.
Muscle force measured using "break" testing with a hand-held myometer in normal subjects aged 20 to 69 years, Phillips BA, Lo SK, Mastaglia FL.
-- Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Australian Neuromuscular Research Institute, Perth.
Arch Phys Med Rehabil. 2000 Oct;81(10):1442-3.
OBJECTIVE: To measure the strength of 17 muscle groups in the upper and lower extremities in a large group of healthy subjects using "break" testing with a hand-held myometer, and to examine the intrasession and intersession reliability of the testing protocol. SUBJECTS AND INSTRUMENTATION: A convenience sample of 20 men and 20 women in each decade of age from 20 to 69 years (n = 200) was tested using a Penny & Giles hand-held myometer. RESULTS: Reliability coefficients were >.85 for both intrasession and intersession reliability, except for the ankle dorsiflexors. Men exerted a significantly greater force than women for all muscle groups. Age, weight, and side of testing were significant predictors of force in the majority of muscle groups. The fifth percentile values, as the lower limit of normal, are reported separately for gender and side of testing for each decade of age. CONCLUSION: Using the testing protocol specified in this study, data from patients with various neuromuscular diseases may be compared with the appropriate gender- and age-matched normal data to accurately identify the presence of weakness.
Hand-held dynamometry reliability in persons with neuropathic weakness,
Kilmer DD, McCrory MA, Wright NC, Rosko RA, Kim HR, Aitkens SG.
-- Department of Physical Medicine and Rehabilitation, School of Medicine, University of California, Davis, USA.
Arch Phys Med Rehabil. 2000 Nov;81(11):1538-9.
OBJECTIVE: To determine test-retest reliability of hand-held dynamometry (HHD) in measuring strength of persons with neuropathic weakness. DESIGN: Intratester and intertester reliability of HHD-measured strength over a 7- to 10-day period. In addition, HHD knee strength was compared with criterion standard of fixed dynamometry (FD). SETTING: Human performance laboratory of a university. PARTICIPANTS: Convenience sample of ambulatory outpatients with Hereditary Motor and Sensory Neuropathy, Type I (HMSN) (n = 10) and able-bodied controls (CTL) (n = 11). MAIN OUTCOME MEASURE: Maximal isometric torque. RESULTS: Intratester intraclass correlation coefficients (ICCs) were high, generally ranging from .82 to .96 for HHD- and FD-measured strength for both HMSN and CTL groups. There were no significant differences between sessions for HHD-measured strength, while FD-measured strength was only significantly different for knee extension (p < .01). Intertester reliability was generally good for both HHD- and FD-measured strength, with ICCs ranging from .72 to .97 for HMSN and CTL groups. Exceptions were knee extensors and ankle dorsiflexors for the CTL group. Knee extensor strength was significantly lower measured by HHD compared with FD (p < .01), but knee flexor strength was similar for the two methods. CONCLUSION: HHD appears to be a reliable method to measure maximal isometric strength in persons with neurogenic weakness, and may be useful to quickly and objectively evaluate strength in the clinical setting.
Decrease in quadriceps inhibition after sacroiliac joint manipulation in patients with anterior knee pain, Suter, E., McMorland, G., Herzog, W., Bray, R.
Background: Evidence exists that conservative rehabilitation protocols fail to achieve full recovery of muscle strength and function after joint injuries. The lack of success has been attributed to the high amount of muscle inhibition found in patients with pathologic conditions of the knee joint. Clinical evaluation shows that anterior knee pain is typically associated with sacroiliac joint dysfunction, which may contribute to the muscle inhibition observed in this patient group. Objective: To assess whether sacroiliac joint manipulation alters muscle inhibition and strength of the knee extensor muscles in patients with anterior knee pain. Design and Setting: The effects of sacroiliac joint manipulation were evaluated in patients with anterior knee pain. The manipulation consisted of a high-velocity low-amplitude thrust in the side-lying position aimed at correcting sacroiliac joint dysfunction. Before and after the manipulation, torque, muscle inhibition, and muscle activation for the knee extensor muscles were measured during isometric contractions using a Cybex dynamometer, muscle stimulation, and electromyography, respectively. 5>