Initially, two constant current high voltage stimulators delivered ten single stimuli twitches with biphasic square pulses at widths of 300 μs. A train generator was then switched on, triggering the delivery a 35 Hz current in bouts of 3 seconds periods separated by 1-second pause for a total of 40 tetanic contractions. In immediate succession to the tetanic contractions a second series of ten single twitch stimuli ended the protocol. Figure 2 show an example of an actual recording of the force response curve.