The effect of exercise training on functional recovery after sciatic nerve crush in the rat

Two separate experiments were carried out in order to evaluate the influence of moderate swim training and treadmill running on the rate of recovery of sensorimotor function following sciatic nerve injury in the rat. Nerve injury was induced by sciatic nerve crush. In the first experiment, rats were subjected to swim exercise (180 m daily), either for 7 days before, or for 14 consecutive days after nerve injury. In the second experiment rats were exercised on a motor driven treadmill device (10 m/min for 30 min twice daily) for 21 days. The recovery from nerve injury was assessed by means of an analysis of the free walking pattern (motor function) and the foot withdrawal reflex (sensory function) by electrical stimulation. The swim training program before or after crush did not affect the recovery of locomotor or sensory function. Treadmill running significantly deteriorated the gradual return of motor function (p < 0.05), but did not influence sensory recovery. We conclude that swim training does not interfere with functional sensorimotor recovery after sciatic nerve injury, and that a mild program of treadmill running retards recovery. We hypothesize that the retardation of recovery as a result of treadmill running is the consequence of the stress inflicted by the negative reinforcement used in the treadmill, or due to the severity of the training. /Ø?>