200 Section - Multilevel assessment and analysis of muscle function in stroke patients based on EMG signals

18 stroke patients and 18 healthy controls were included in the study. Surface EMG signals of 9 muscles related to upper limb movements were collected during single-joint movements and multi-joint coordinated movements. The integral values (iEMG) and median frequency (MDF) of the muscle electrical activity segments were extracted to evaluate the muscle contraction function. The skewness (Ske) and kurtosis (Kur) of the signals were calculated. The average Z value and the percentage of the stable window were calculated using the reverse arrangement (RA) test to analyze the stationarity characteristics of the EMG signals. The intermuscular coupling network was constructed based on the matrixed Rényi α-entropy, and graph theory parameters such as clustering coefficient and global efficiency were extracted to evaluate the muscle coordination patterns. Statistical analysis of differences between groups was conducted for all indicators.

Results:

The iEMG and MDF of certain muscles in patients decreased, the distribution patterns of EMG signal (Kur, Ske, and signal-stationarity) were altered, and the strength of coupling between most muscle pairs were significantly decreased. In the single-joint abduction movement, the characteristic path length of the patient group was significantly increased. In the multi-joint combing movement, the total node strength, in- and out clustering coefficients, overall clustering coefficient, global efficiency, and local efficiency of the nodes were all significantly decreased.

Conclusion:

The muscle contraction performance, distribution patterns of EMG signal and intermuscular coordination of stroke patients were significantly abnormal. The relevant parameters can serve as quantitative indicators for evaluating muscle function and provide a scientific basis for formulating personalized rehabilitation treatment strategies for stroke patients.