Fig. 5. Force–time relationship in twitch (2 ms pulse, 1 Hz; gray line) and tetanus (2 ms pulse, 400 Hz, 100 ms duration; black line) for CMP (A) and SMR (B) preparations. The tetanus trace in B also illustrates the temporal aspects of force that we measured. The lowest black line illustrates the timing of electrical stimuli. Please note that the scale of the time axis does not permit accurate depiction of the timing of electrical stimuli. T_L, latent period, measured as the time from the beginning of the first rectangular pulse stimulation to the initial rise in force; T_P, time from the initial rise in force to the peak force; T₅₀, time required for force to fall from the peak to 50% peak.