FRACTAL ANALYSIS OF SURFACE EMG SIGNALS FROM THE BICEPS

Nonlinear analysis techniques are necessary to understand the complexi ty of the EMG. The purpose of the present study was to determine the f ractal dimension of surface EMG obtained from the biceps brachii of no rmal subjects during isokinetic flexion-extension of the arm. The meas urements were obtained with different loading conditions on the arm an d for various rates of flexion-extension. Fractal dimensions of the su rface EMG signals were calculated for each of these conditions. ANOVA results showed statistically significant differences between the fract al dimensions calculated for different loading conditions and rates of flexion-extension (P less than or equal to 0.005). Linear regression analysis showed a correlation coefficient of 0.99 between the fractal dimension and the load, and a correlation coefficient of 0.98 between the fractal dimension and the rate of flexion-extension. The results o f the study show that the fractal dimension can be used along with oth er parameters to characterize the EMG signal. (C) 1997 Elsevier Scienc e Ireland Ltd.