The Surface-electromyographic Examination Of Upper Extremity Muscles During Rehabilitation Process For Hemiparetic Stroke Patients

Objective The objective of this study is to explore changes of surface electromyography(s EMG) signals measured from biceps brachii, flexor pollicis brevis and first dorsal interosseeous muscles during maximum isometric voluntary contractions in stroke patients with hemiparesis in the process of rehabilitation, and their relevance to motor function recovery, also with an attempt to provide theoretical guideline for clinical rehabilitation programs. Methods Twenty stroke patients and 10age- and gender- matched healthy controls were recruited. In the patients’ course of convalescence, for all recruited subjects, the s EMG signals were recorded bilaterally from the biceps brachii, flexor pollicis brevis and first dorsal interosseeous muscles during their maximum isometric voluntary contractions for elbow flexion, thumb flexion and index finger abduction, respectively. For stroke patients, such recording procedure was repetitively performed on the paretic side in the course of convalescence. Both root-mean-square(RMS) amplitude and median frequency(MDF)were calculated for recorded surface EMG signals. The upper-extremity component of Fugl-Meyer assessment scale(FMA-UE) and manual muscle test(MMT) on each examined muscle were performed to assess motor function and muscle strength of upper extremity respectively for each stroke patient. Results There were no significant differences in either RMS or MDF value between the left and right sides of the healthy control subjects(P>0.5). Significant differences existed in both RMS and MDF at the affected side compared with the unaffected side and either side of controls(P<0.5).The unaffected side of patients had significantly larger RMS and MDF values than either side of the healthy control group(P<0.5). For the affected side of stroke patients,both RMS and MDF values presented a tendency of increasing during the course of rehabilitation training(counted as days), with significant differences between the value obtained at the first and the last time(P<0.5). The scores of FMA-UE and MMT at affected side was positively correlated with RMS and MDF on upper extremity muscles, also with statistical significance. Conclusions The surface electromyography examination of hemiplegic upper extremity muscles of stroke patients is able to reflect rehabilitation process, and the muscle strength and motor function recovery as well. It can be considered as a quantitative tool for rehabilitation evaluation. Furthermore, it also provides the theoretical basis and guidance for targeted functional training of upper limb in the rehabilitation program.