Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology
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J Electromyogr Kinesiol · Aug 2009
Reliability of electromyographic amplitude values of the upper limb muscles during closed kinetic chain exercises with stable and unstable surfaces.
The purpose of the present study was to evaluate the intra and interday reliability of surface electromyographic amplitude values of the scapular girdle muscles and upper limbs during 3 isometric closed kinetic chain exercises, involving upper limbs with the fixed distal segment extremity on stable base of support and on a Swiss ball (relatively unstable). Twenty healthy adults performed the exercises push-up, bench-press and wall-press with different effort levels (80% and 100% maximal load). Subjects performed three maximal voluntary contractions (MVC) in muscular testing position of each muscle to obtain a reference value for root mean square (RMS) normalization. ⋯ The interday reliability of normalized RMS values ranged between good and excellent (ICC 0.52-0.98). Finally, it is suggested that the reliability of normalized electromyographic amplitude values of the analyzed muscles present better values during exercises on a stable surface. However, load levels used during the exercises do not seem to have any influence on variability levels, possibly because the loads were quite similar.
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J Electromyogr Kinesiol · Jun 2009
Reliability of posturographic measurements in the assessment of impaired sensorimotor function in chronic low back pain.
The evaluation of postural stability using posturography could be both a valuable functional diagnostic and treatment outcome monitoring tool in rehabilitation practice of patients with chronic low back pain (cLBP). No evidence, however, seems to exist, whether or not such posturographic measures are reliable in these patients and therefore clinically and scientifically useful. The aims of this study were manifold and aimed at investigating (1) differences of posturographic measures between cLBP patients and healthy controls (HCs), (2) short- (intrasession-) and long-term (intersession-) reliability of these measurements, and (3) the relationship between both pain intensity and test-related feelings and significant learning effects of the posturographic measures in cLBP. A total of 32 cLBP patients and 19 non-sportive HCs completed (1) comprehensive clinical examination, (2) quantitative posturographic testing (SMART EquiTest, Neurocom International, Clackamas, Oregon) that included all the sensory organisation test (SOT), the motor control test (MCT) and the adaptation test (ADT) and (3) psychological ratings of pain as well as posturographic test related personal feelings and fear associated beliefs. Of these, 22 cLBP patients who received no therapy repeated all measurements and examinations on a second day, 2-3 weeks later. Results revealed significant differences between cLBP patients and HCs in the more demanding postural test conditions of the SOT and the SOT composite score only. Intra-session reliability testing demonstrated significant improvements of the SOT and ADT measures for both HCs and cLBP patients. Results of long-term reliability testing showed significant improvements of the more challenging SOT conditions and SOT composite score. VAS ratings of pain, feelings and fear associated beliefs were not associated with such longitudinal changes. ⋯ Our findings suggest that the significant learning effects observed for the SOT conditions may limit the clinical application of SMART EquiTest postural stability measures for cLBP patients in rehabilitation everyday practice. Further development in software processing will be necessary to identify new postural parameters that are less prone to learning effects.
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J Electromyogr Kinesiol · Apr 2009
The interpretation of abdominal wall muscle recruitment strategies change when the electrocardiogram (ECG) is removed from the electromyogram (EMG).
The purpose of this study was to determine the effect of the ECG artifact on low-level trunk muscle activation amplitudes and assess the effectiveness of two methods used to remove the ECG. Simulations were performed and percent error in root mean square (RMS) amplitudes were calculated from uncontaminated and contaminated EMG signals at various ECG to EMG ratios. Two methods were used to remove the ECG: (1) filtering by adaptive sampling (FAS) and (2) Butterworth high pass filter at 30 Hz (BW-30 Hz HPF). ⋯ These errors increased with larger ECG to EMG ratios. Both removal methods reduced the errors to below 10%, but the BW-30 Hz HPF method was more time efficient in removing the ECG artifact. Different statistical findings were observed among the muscle sites for the ECG contaminated model compared to the ECG removed model, which resulted in different conclusions concerning neuromuscular control.
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J Electromyogr Kinesiol · Feb 2009
Randomized Controlled Trial Comparative StudyComparison of surface electromyographic activity of erector spinae before and after the application of central posteroanterior mobilisation on the lumbar spine.
Lumbar spine accessory movements, used by therapists in the treatment of patients with low back pain, is thought to decrease paravertebral muscular activity; however there is little research to support this suggestion. This study investigated the effects of lumbar spine accessory movements on surface electromyography (sEMG) activity of erector spinae. A condition randomised, placebo controlled, repeated measures design was used. sEMG measurements were recorded from 36 asymptomatic subjects following a control, placebo and central posteroanterior (PA) mobilisation to L3 each for 2min. ⋯ Surface electromyographic data were recorded from the musculature adjacent to L3, L5 and T10. There were statistically significant reductions of 15.5% (95% CI: 8.0-22.5%) and 17.8% (95% CI: 12.9-22.4%) in mean sEMG values following mobilisation compared with the control and placebo, respectively. This study demonstrates that a central PA mobilisation to L3 results in a statistically significant decrease in the sEMG activity of erector spinae of an asymptomatic population.
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J Electromyogr Kinesiol · Dec 2008
ReviewTowards remote monitoring and remotely supervised training.
The growing number of elderly and people with chronic disorders in our western society puts such a pressure on our healthcare system that innovative approaches are required to make our health care more effective and more efficient. One way of innovating healthcare can be obtained by introducing new services that support and enable these elderly and people with chronic disorders in a more independent living and in self management with respect to their disorders. Examples of such services are remote monitoring and remotely supervised training (together RMT). ⋯ Until now, the main focus has been on the technical realization of the sensing and transportation part of it. The development of intelligent decision support systems is still in its infancy and clinical validation studies and models how to implement these services and how to make them profitable are largely lacking. In conclusion, the combination of Biomedical Engineering with Information and Communication Technology has opened a new extensive area of research and development with a high potential to have substantial impact on our future healthcare.