An index of the functional condition of rat sciatic nerve based on measurements made from walking tracks

There is no widely accepted quantitative method for evaluating the functional effects of peripheral nerve damage in animals. In the present study, a method for evaluating sciatic nerve damage was developed from measurements of the prints of the hind feet of walking rats preserved on X-ray film. Four variables were measured from these tracks, and comparisons between the damaged (experimental) and intact (normal) side were converted to percent deficits and averaged to obtain a “sciatic functional index” (SFI). The SFI was then measured under normal conditions, after nerve transection, nerve crush, and sham procedures. Reliability and repeatability of the SFI were found to be excellent. The effects of sciatic nerve transection and nerve crush evaluated by this method agreed very well with other methods of evaluating nerve damage. We conclude that the SFI provides a simple, accurate, reliable, and repeatable method for evaluating the functional condition of sciatic nerve in rats.