Several risk factors have been identified that predispose to the development of post-polio syndrome. One is the severity of the polio and resulting paralysis (Halstead et al 1985; Agre and Rodriquez 1990; Windebank et al 1991; Trojan et al 1994). The more severe the disease the more likely a patient will develop post-polio syndrome. Presumably this is due to a fewer number of motor neurons, which will result in earlier weakness when these few remaining motor neurons with enlarged motor units degenerate. The age at onset of the poliomyelitis also is a risk factor. Acute poliomyelitis in adolescents and adults is more severe than in infants and small children (Jubelt and Cashman 1987), and the former patients are more likely to develop post-polio syndrome (Halstead et al 1985; Klingman et al 1988). Thus, older age at the time of the acute poliomyelitis as a risk factor probably relates to the greater severity of the disease. In one study another risk factor is the amount recovery; the greater the recovery, the more likely post-polio syndrome will occur (Klingman et al 1988), suggesting that reinnervation is unable to be maintained 30 to 40 years later. In these patients who do recover totally or partially, excessive exercise or overuse appears to predispose them to post-polio syndrome (Klingman et al 1988; Trojan et al 1994). The only one of these risk factors that can be addressed preventively is the overuse of muscles (excessive exercise). Patients need to be educated not to excessively exercise and to pace their activities. Post-polio syndrome patients should not allow themselves to have muscle fatigue (increased weakness, muscle flabbiness, muscle numbness, muscle soreness) or even excessive generalized fatigue after exercise. Their exercise must be paced and be nonfatiguing.
In their descriptive study, Winberg and colleagues found that despite a progressive physical disability, people with late effects of polio are physically active, but much of it is performed as part of their household activities and not as traditional exercise (Winberg et al 2014a). The relationship between physical activity, life satisfaction, and age further supports the general contention that an active lifestyle is an important factor for perceived well being among older people. In ambulatory persons with late effects of polio, knee muscle strength and gait performance explain only a small portion of physical activity, necessitating further studies to understand as to how other impairments, activity limitations, environmental factors, and personal factors influence physical activity in persons with late effects of polio (Winberg et al 2014b).