Patients improved their function through substitution of other muscles or using passive tendon tension by alternate posturing. Substitution was exquisitely effective. It also introduced the potential for overuse of remaining muscles. The current post-polio syndrome is characterized by loss of strength, increased fatigue, and muscle or joint pain. There is strong experimental evidence supporting the loss of muscle fibers through damage from overuse, edema, inflammatory cell and fiber degeneration.
Muscle pain is a sign of injury.
The key point is that most patients with loss of function are not suffering from inactivity. Exercise can make only a small contribution. The primary therapeutic program is to reduce the strain on these muscles by lifestyle modification or assistive equipment. If strain can be relieved, there has been mild improvement of strength and significant improvement of function. The diagnosis is one of exclusion.