Figure 16

Muscle contractile parameters for 0.5 Hz and 2 Hz activation. (a) Definition of the twitch contractile parameters; Thc time from start of contraction to moment when force is half its maximum value, Tc time from start of contraction to moment when force is at its maximum value, Thr time from start of contraction to when force decreases to half its maximum value during the relaxation phase, Fmax maximum twitch force. (b) Peak force normalized to muscle physiological cross-sectional area. (c) Half peak contraction time (Thc). (d) Peak contraction time (Tc). (e) Half relaxation time (Thr). Twitch parameters for 0.5 Hz are compared to the first 2 Hz contraction for seventeen subjects (n = 17).