Measurement of forelimb function by digital video motion analysis in rat nerve transection models

The object of this study was to demonstrate that digital video motion analysis is a quantitative, valid, and reproducible method for evaluation of function in the rat model of forelimb nerve transection and repair. Median, ulnar, and radial nerves were transected and directly repaired in 220 g Sprague-Dawley rats. Normal rats and sham-operated rats served as controls (six rats in each group). Two-dimensional (2D) digital video motion analysis was used to capture the gait cycle and quantify joint movement and changes in toe spread. Recordings were made preoperatively and at 1, 4, 8, 12, and 16 weeks postoperatively. Wrist and metacarpophalangeal (MP) joint extension decreased after radial nerve injury, and wrist and MP joint flexion decreased after combined median and ulnar nerve injury or injury to the median nerve only. Toe spread decreased after combined median and ulnar nerve injury and after radial nerve injury. Median or ulnar nerve injury alone did not lead to a significant change in toe spread. 2D digital video motion analysis can be used to quantify movement of the wrist and the MP joint in rats. It is a valid method to evaluate functional deficit and recovery after nerve injury and repair in the forelimb.