The Influence of Two Physical Activity Programs on Bone and Muscle Health in Youth With Cerebral Palsy and Other Neuromotor Impairments

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URL: https://hdl.handle.net/1880/120379

Abstract

Weight-bearing physical activity is crucial for building strong bones, especially during childhood and adolescence when bones grow rapidly. During this time, physical activity, muscle-bone interactions, and gravity help stimulate bone development. However, in conditions that limit mobility, such as cerebral palsy (CP) and other non-progressive neuromotor impairments (CP-like), physical activity is reduced, which can lead to poor bone health. This increases the risk of fractures and may lead to osteoporosis in adults with CP. This thesis examines bone health in children and youth with CP and CP-like conditions using peripheral quantitative computed tomography (pQCT) scans of the tibiae. Bone and muscle parameters, including bone mineral content (BMC), bone mineral density (both trabecular and cortical; BMD), bone size, and muscle size, were compared to age-, sex-, and ethnicity-matched peers from a typically developing population. A total of 22 participants from all Gross Motor Function Classification System (GMFCS) levels (I-V) were included. This study found smaller, thinner and weaker bones and lower muscle strength in children and adolescents with CP and CP-like conditions across all GMFCS levels, with deficits relating to functional ability. As weaker bones increase the incidence of fragility fractures, causing pain and predisposing future comorbidities, this thesis further evaluated the effects of two physical activity programs on bone and muscle strength. Robot-assisted walking in three participants with the greatest functional limitations found upright mobility may improve bone strength. In contrast, power training in eight participants with the greatest functional abilities found no adaptations in bone or muscle. These findings suggest that while bone health is a concern across all functional abilities, adaptations appear to correlate to the loading one previously experienced, having the greatest impacts in those who do not regularly ambulate. This highlights the importance of tailored physical activity programs based on functional ability during growth and could inform strategies for improving musculoskeletal health in children and youth with CP and CP-like conditions.

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