Muscle twitches, evoked by sciatic nerve stimulation, in control and spinal cord injured (SCI) animals. Stimulus-response curves were generated by stimulating the sciatic nerve and recording muscle twitches from the triceps surae muscles. A: Representative twitches from animals with SCI (red) and control (black) obtained by stimulus with intensity of 0.7 mA. B: Cumulative averages of the muscle responses from SCI and control animals plotted against stimulus intensity. It is noteworthy that muscle twitches are more easily evocable in animals with SCI than in controls. Note also the difference became differentiated at stimulus intensities 0.7 to 1 V (p < 0.05). C: In SCI animals, stimulus-response curve in weak muscles was different from that in strong muscles. Note that the threshold in weak muscles (0.05 V) was much lower than the threshold in strong muscles (0.6 V). D: Average minimal threshold was significantly lower in SCI animals compared to controls (p < 0.003).