Neuromuscular evaluation using rat gait analysis.

We have developed a rat gait analysis model to evaluate if ankle angle and other associated gait parameters could consistently define normal peroneal nerve and anterior tibialis muscle function. The second part of the study was designed to determine if such a model would be useful to measure recovery of function after a peroneal nerve crush injury (NCI). A clear plexiglas tunnel was designed for high-speed frame videotaping and subsequent computergraphic gait measurement and analysis. Normal gait patterns for ankle angle, back height, step and stride lengths and the stance and swing times were determined in 8 rats. Data analysis demonstrated no significant left/right differences for any of the variables (ANOVA) with the exception of step length. Subsequently, 12 rats with a peroneal NCI were evaluated. All gait parameters evaluated from the injured side were significantly different from the uninjured side after injury except stride length. Ankle angle was the most sensitive outcome variable. Weekly gait analysis provided objective measurements as the ankle angle gradually returned to normal within 3 weeks. The rat gait model is a sensitive and reproducible method for non-invasive evaluation of neuromuscular function during nerve recovery after a peroneal crush injury.