The effect of stimulation condition on force rise time. Force rise time50% varied with stimulation condition (p < 0.001), being significantly higher in the supra-max condition than in either the sub-max (p < 0.05) or block conditions (p < 0.05). There was no difference between sub-max and block conditions (p = 0.65; n = 10, 10, 7 for supra-max, sub-max and block, respectively).