An evaluation of impairment, mobility and quality of life in Polio survivors, change in muscle strength over time and the effects of an arm ergometry aerobic exercise programme.
Many Polio survivors report new problems, including new muscle weakness, fatigue, decreased mobility and pain (Halstead, 2004). There is a lack of consensus regarding the rate of decline in muscle strength and function of Polio survivors (Stolwijk-Swuste et al., 2005), the reasons for the new symptoms such as fatigue and the cause of declining mobility. As a result of their disability many Polio survivors report significant barriers to physical activity (Becker and Stuifbergen, 2004) and the prevalence of lifestyle related health risk factors is high (Gawne et al., 2003), which provides further risk of disease burden and disability. A number of research questions were identified and three studies addressing these questions are presented in the thesis.
Polio survivors attending Beaumont hospital have had their muscle strength assessed using fixed dynamometry since 1999. A longitudinal study of the rate in decline in muscle strength was completed, including patients who had attended for assessment for at least four years. A slow rate of decline in strength over a period of between four and twelve years in the 65 Polio survivors was identified. The rate of decline identified, of between one and two percent was similar to that reported in normal ageing.
The second study sought to assess the presence of motor fatigue, its relationship with subjective fatigue and investigate whether motor fatigue was a contributing factor to decreased mobility. In addition, a range of impairments, mobility and quality of life were assessed in 30 Polio survivors and 30 age and sex matched healthy controls. Significant differences between the groups in muscle strength, subjective fatigue, mobility, pain and quality of life were identified. Motor fatigue was assessed by analysing the rate of decline in Maximum Voluntary Isometric Contraction over 30 seconds and Polio survivors had significantly greater motor fatigue in hand grip but not in lower limb muscle groups. Motor fatigue was not related to subjective fatigue or to mobility. Relationships between impairments and quality of life were identified, and pain, fatigue and elevated energy cost of walking were associated with worse quality of life. Muscle strength was significantly associated with mobility.
The third study sought to develop an aerobic exercise programme, which was designed to overcome the barriers to exercise reported by Polio survivors. The effects of a home-based arm ergometry programme were investigated in a randomised controlled trial of 55 Polio survivors. Changes in physical fitness, assessed using a submaximal fitness test, fatigue, pain, activity and quality of life were not significantly better in the intervention group at follow-up compared with the control group. However, Polio survivors, allocated to the intervention group had significantly lower blood pressure at follow-up. Compliance with the programme was excellent and participants completed exercise sessions of approximately 20 minutes three times per week. There were no overall adverse effects on fatigue, pain or muscle strength. Participants perceived the programme to be of benefit. Although the changes in physical fitness and impairments related to the late-onset sequelae of Polio were not significant the programme did allow otherwise inactive Polio survivors to access aerobic exercise and experience the associated health benefits.