Applications in Musculoskeletal Physical Therapy

Surface electromyography (sEMG) is typically applied in musculoskeletal physical therapy for the assessment of disturbed motor control and for monitoring change with rehabilitation. This chapter explores fundamental methods of EMG assessment as a means of evaluating neuromuscular impairment in patients with musculoskeletal disorders with a focus on two of the most common musculoskeletal complaints, namely, low back pain and neck pain. Distinct modifications of the sEMG signal can be identified during sustained voluntary or electrically elicited muscle contractions, and the analysis of myoelectric manifestations of muscle fatigue can provide important information about physiological changes evolving in the muscle. The amplitude of the surface EMG can be estimated by a scheme of demodulation, smoothing, and relinearization. An approach to monitoring the amplitude of activity of muscles with sEMG is to measure tuning curves. The chapter further reviews some of the most frequently applied analyses in musculoskeletal physical therapy research.