Fig. 1.

Normalized dorsiflexor torque and tibialis anterior electromyographic activity (EMG) during sustained isometric contractions at different levels of maximal torque. Values are expressed as means ± SE. Contractions were performed at 30 (○), 60 (□), and 100% (△) of maximum voluntary contraction (MVC) torque. Open symbols are torque, whereas solid symbols are EMG data. Torque data are normalized to the peak value obtained at the start of 100% MVC contraction. EMG data during the 30 and 60% MVC contractions are normalized to the value obtained during the brief MVC performed in the recovery period following the 30% MVC contraction. For the 100% MVC contraction, EMG data are normalized to the mean value from the first 10 s of exercise.