Fig. 1. Example of isometric twitch contractions at 21°C of soleus (A) and extensor digitorum longus (B) muscle of Suncus etruscus stimulated simultaneously with a supramaximal electrical pulse of 1 ms duration. The curves are digital scans of original recordings. Time to peak force (t_p) is the time between the stimulus (upward-pointing arrow) and the occurrence of maximal force, and the 50, 75 and 90% relaxation times (t_r50, t_r75, t_r90) are the times for the decay from maximal force to 50, 25 and 10% of maximal force, respectively.