Muscular function in late polio and the role of exercise in post-polio patients.

Many post-polio individuals note new musculoskeletal and neuromuscular symptoms. In general, post-polio individuals are found to be weaker than non-postpolio individuals. Muscle weakness appears to play a role in functional limitations in post-polio individuals, especially for such activities as walking and stair climbing. Many post-polio individuals also have deficits in muscular work capacity and strength recovery following activity. Importantly, post-polio individuals are known to have normal perception of local muscle fatigue during activity. The perception of fatigue within the working muscle can be used to modify activity and to assist the individual in the avoidance of excessive local fatigue during exercise and performance of activities of daily living. Recent studies have shown that judicious exercise can improve muscle strength, range of motion, cardiorespiratory fitness, efficiency of ambulation as well as add to the patient's sense of well-being. These benefits appear to occur when activity and exercise are kept within reasonable limits in order to avoid excessive muscular fatigue and/or joint or muscle pain. It is suggested that post-polio patients be instructed to avoid activities that cause increasing muscle or joint pain or excessive fatigue, either during or after their exercise program as the performance of activity at too high a level may lead to overuse/overwork problems. The recent literature indicates that exercise within the constraints of fatigue and pain leads to a number of beneficial physiologic adaptations. Judicious exercise should be viewed as an adjuvant in the overall therapeutic program of the post-polio patient, when the individual has the physiologic capacity to exercise.