Changes in muscle contraction properties after SCI. A: representative normalized muscle twitches from SCI (red) and control (black) animals normalized to peak twitch force. Note the slow rising and falling of the twitch from SCI animals. The curve segments marked a, b, and c are different periods of muscle contraction that was analyzed separately below (the straight line marks the (b) segment of the curve). B: A significant correlation between rising and falling slopes, indicating that twitches with higher rising slope are associated with higher falling slope value. Data in B are from all muscles of SCI and control animals. C: The mean value of the rising slope in normal animals was significantly higher than in controls (*p = 0.033). D: The mean value of the falling slope of the entire decay period (b and c) was significantly lower in SCI animals compared to control. E: The mean value of the first part of the decay period of muscle contraction marked (b) was lower on SCI compared to control, however, the difference was not statistically significant (p = 0.411). F: The mean value of the falling slope at the last part of the decay marked (c), was significantly lower in SCI animals compared to controls (p = 0.012).