Assessment of subjective and motor fatigue in Polio survivors, attending a Postpolio clinic, comparison with healthy controls and an exploration of clinical correlates

Purpose: Polio survivors experience declining mobility, pain and fatigue. The extent of motor fatigue and its impact on mobility and quality of life, in addition to other commonly reported impairments requires evaluation. Methods: An observational, case-control, cross-sectional design was used to assess 30 Polio survivors and 30 age- and sex-matched controls. Muscle strength and motor fatigue were assessed using fixed dynamometry. Fatigue, pain and quality of life were assessed using the Piper Fatigue Scale, the Fatigue Severity Scale, visual analogue scales and the RAND Short Form-36, respectively. An 8-min walking test, including physiological cost index (PCI), evaluated mobility. Results: A significant difference in motor fatigue was identified only in hand grip (p=0.03). Polio survivors were significantly weaker (p<0.001) and more fatigued (p<0.001) than controls. Motor fatigue was not related to subjective fatigue, mobility or quality of life. Muscle strength predicted mobility. Pain and fatigue were associated with lower mental quality of life, while PCI was associated with physical quality of life. Conclusion: Motor fatigue has been identified in Polio survivors but was only significantly different in hand grip, using this approach. Pain, fatigue and elevated energy cost of walking negatively influenced quality of life. Motor fatigue was unrelated to subjective fatigue, mobility or quality of life.