Fig. 3.

Increases in muscle activation and twitch. The peak torque of plantar flexion produced by stimulation of the MG nerve branch is plotted against the root mean square amplitude of M-waves. Values were normalized with respect to those obtained for the maximal stimulation intensity and averaged (whiskers indicate standard deviation) across subjects and across the nine preceding stimulation intensities, from 10% to 90% of the maximal. Note that increases in the amplitude of MG twitches were consistently and strongly associated to increases in M-wave amplitude (see Pearson Coefficient of Correlation and the significance level). The dashed trace represents the regression line fitted to the data.