Comparison of force-velocity characteristics obtained using twitches and tetani from in situ rat skeletal muscles.

Force-velocity and power-velocity characteristics of three different rat skeletal muscle-tendon complexes (soleus, extensor digitorum longus and medial gastrocnemius) were obtained using twitch and tetanic contractions. No differences were found between twitches and tetani with respect to the shape of the force-velocity curves, or to the velocity at which the highest power output occurs. The results indicate that twitch contractions can be used to standardize muscle preparations in experiments aimed to study muscle energetics during dynamic contractions.