In vivo force velocity relation of human m. gastrocnemius medialis during maximal voluntary preloaded contractions

The force velocity relation (f-v-r) of the human gastrocnemius medialis was assessed using maximum voluntary preactivation prior to shortening at different angular velocities. Compared to previous work, preloading resulted in increased torque outputs and clearly decreased slope characteristics of the f-v-r at higher velocities. This might be explained by an elastic recoil of the Achilles tendon that adds to active muscle force.