Fig. 4

Normalized cumulative frequency curve of T₂ (CFZ) after the pronation exercise. The filled circles, open circles and closed squares indicate the results obtained after pronation exercise of 25%, 15% and 5% MVC, respectively. The bold curves indicate the CFZ of resting muscle, and the mean (Z_m) was 0 and the SD was 1.0. The bold vertical lines represent the threshold of the activated muscle (Z_T = 2.56)