Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology
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J Electromyogr Kinesiol · Oct 2012
ReviewThe basis for spinal manipulation: chiropractic perspective of indications and theory.
It is reasonable to think that patients responding to spinal manipulation (SM), a mechanically based therapy, would have mechanical derangement of the spine as a critical causal component in the mechanism of their condition. Consequently, SM practitioners routinely assess intervertebral motion, and treat patients on the basis of those assessments. ⋯ This paper reviews the putative mechanical features of the subluxation and three theories that form the foundation for much of chiropractic practice. It concludes with discussion of subluxation as an indicator for SM therapy, particularly from the perspective that subluxation may be one contributory cause of ill-health within a "web of causation".
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J Electromyogr Kinesiol · Jun 2012
Comparative StudyRelationship between back muscle endurance and voluntary activation.
There is some evidence that the Biering-Sorensen endurance test can discriminate low back pain sufferers from healthy individuals and can predict future back pain. This test relies on the subject's ability to voluntarily drive the back muscles. This neural drive, termed voluntary activation (VA) can be measured using the twitch interpolation technique. ⋯ The mean (SEM) endurance time was 174.9 (12.8)s. There was no correlation between endurance and VA at either 100% MVC (r(2)=0.01, P=0.72) or at 50% MVC (r(2)=0.11, P=0.16). These findings indicate that the endurance of the back muscles, as assessed using this widely utilised test does not appear to be related to a subject's ability to drive their back muscles voluntarily either maximally or submaximally.
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J Electromyogr Kinesiol · Dec 2011
Reliability of surface electromyography timing parameters in gait in cervical spondylotic myelopathy.
The aims of this study were to validate a computerised method to detect muscle activity from surface electromyography (SEMG) signals in gait in patients with cervical spondylotic myelopathy (CSM), and to evaluate the test-retest reliability of the activation times designated by this method. SEMG signals were recorded from rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and medial gastrocnemius (MG), during gait in 12 participants with CSM on two separate test days. Four computerised activity detection methods, based on the Teager-Kaiser Energy Operator (TKEO), were applied to a subset of signals and compared to visual interpretation of muscle activation. ⋯ A detection method based on a combined slope and amplitude threshold showed the highest agreement (87.5%) with visual interpretation. With respect to reliability, the standard error of measurement (SEM) of the timing of RF, TA and MG between test days was 5.5% stride duration or less, while the SEM of BF was 9.4%. The timing parameters of RF, TA and MG designated by this method were considered sufficiently reliable for use in clinical practice, however the reliability of BF was questionable.
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J Electromyogr Kinesiol · Dec 2011
Altered activity of the serratus anterior during unilateral arm elevation in patients with cervical disorders.
Altered activity in the axioscapular muscles is considered to be an important feature in patients with neck pain. The activity of the serratus anterior (SA) and trapezius muscles during arm elevation has not been investigated in these patients. The objectives of this study was to investigate whether there is a pattern of altered activity in the SA and trapezius in patients with insidious onset neck pain (IONP) (n=22) and whiplash associated disorders (WAD) (n=27). ⋯ Post hoc comparison revealed a significantly delayed onset of muscle activation and less duration of muscle activity in the IONP group, and in the WAD group compared to the asymptomatic group. There were no group main effects or interaction effects for upper, middle and lower trapezius. This finding may have implications for scapular stability in these patients because the altered activity in the SA may reflect inconsistent or poorly coordinated muscle activation that may reduce the quality of neuromuscular performance and induce an increased load on the cervical and the thoracic spine.
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J Electromyogr Kinesiol · Apr 2011
ReviewPain and motor control: From the laboratory to rehabilitation.
Movement is changed in pain and is the target of clinical interventions. Yet the understanding of the physiological basis for movement adaptation in pain remains limited. Contemporary theories are relatively simplistic and fall short of providing an explanation for the variety of permutations of changes in movement control identified in clinical and experimental contexts. ⋯ This paper describes an expanded theory of the motor adaptation to pain to address these two issues. The new theory, based on clinical and experimental data argues that: activity is redistributed within and between muscles rather than stereotypical inhibition or excitation of muscles; modifies the mechanical behaviour in a variable manner with the objective to "protect" the tissues from further pain or injury, or threatened pain or injury; involves changes at multiple levels of the motor system that may be complementary, additive or competitive; and has short-term benefit, but with potential long-term consequences due to factors such as increased load, decreased movement, and decreased variability. This expanded theory provides guidance for rehabilitation directed at alleviating a mechanical contribution to the recurrence and persistence of pain that must be balanced with other aspects of a multifaceted intervention that includes management of psychosocial aspects of the pain experience.