Objective
To investigate the effect of swimming exercise on the recovery after ischemia/reperfusion injury.Method: Forty male Sprague-Dawley rats were tested. Two groups of 20 rats were formed: 1- and 3-hours ischemia groups. Finally the groups were further divided into 2 groups that went through swimming (swimming groups) and those not (control groups). Baseline recordings of electromyographic and sciatic function index (SFI) were performed, then the femoral vessels of the rat were ligated for the complete ischemia. The reperfusion process was done according to the preset time. The methods to evaluate the functional status of nerve were the nerve conduction study (NCS), SFI and histologic study.Results: On the fourth week of experiment, amplitude of compound muscle action potentials was large in swimming groups compared to the control groups (p＜0.05). On the third week, amplitude was large in 1 hour swimming group compared to the control group. The muscle fiber was large in diameter in 1-hour-ischemic group at 4 week compared to the control, and the sciatic function index showed same results at the 3 hours group.Conclusion: The groups which swimming exercise done early after ischemia/reperfusion got better results compared with the nonswimming group (p＜0.05). The exercise had beneficial effect on motor function recovery after ischemia/ reperfusion injury. (J Korean Acad Rehab Med 2004; 28: 352-357)

Objective
To analyze the degree of injury and patterns of recovery according to the severity and degree of ischemia-reperfusion.

Method: Fifty-three rats were divided into 2 groups by degree of ischemia using ultrasonography. Each group was subdivided into 1 and 3-hours ischemia groups. Baseline recordings were performed, and ligation of the femoral vessels were done. Reperfusion process was done. Nerve conduction study (NCS), Sciatic Function Index (SFI) and histologic study were used.

Results: NCS parameters of the less than 3 hours incomplete insult group showed normal value. More than 1 hour of complete insult induced peripheral nerve injury. On first day and week, amplitude of NCS was small in 3-hour group. Muscle fiber diameter was less in 3-hour group. Although NCS parameters did not reach normal values on 4th week, 3-hour group showed smaller amplitudes. SFI returned to normal level at 4th week. Reperfusion injury was observed by electromyography.

Conclusion: Less than 3 hours of partial ischemia/ reperfusion did not result in any form of injury whereas more than 1 hour of complete insult resulted in peripheral nerve injury with greater injury seen in 3 hour insult group. Neurological recovery was not achieved at 4 th week, and the more severe the ischemia, the poorer was the recovery. (J Korean Acad Rehab Med 2003; 27: 374-381)