Gait compensations in rats after a temporary nerve palsy quantified using temporo-spatial and kinematic parameters.

Abstract

The aim of this work was to test a method for measuring the gait of rats with sufficient sensitivity to detect subtle locomotor changes due to pathology, injury and recovery. The gait of female Sprague-Dawley rats was assessed using an optical motion tracking system and the DigiGait™ imaging system during normal locomotion, shortly after temporary nerve block to the left hind limb and after full recovery. The effect of low treadmill speeds (10-30 cm/s) was initially investigated. Significant changes were detected in the spatiotemporal gait parameters, consistent with those previously reported. The overall ranges of motion in the hip, knee and ankle joints were 37.5° (±7.1°), 50.2° (±9.4°) and 61.6° (±9.1°) and did not appear to change with speed, indicating that for low speed variations, kinematic comparisons across speeds may be possible. Following the induction of a temporary sciatic nerve block, the range of motion of the left ankle and knee during swing decreased by 23° and 33°, respectively (p<0.05). A compensatory change of a greater range of motion at the hip was noted in the contralateral limb (p<0.01). 90 min post injection, most of the gait parameters had returned to normal, however, minor walking deficits were still present. Discriminant analysis showed that a combination of dynamic and kinematic parameters provides a more robust method for the classification of gait changes. This more detailed method, employing both dynamic analysis and joint kinematics simultaneously, was found to be a reliable approach for the quantification of gait in rats.