Grant: Project Grant

Cerebral palsy (CP) is the most common motor disability in children caused by injury to the immature brain. As a result, children with CP have abnormal muscle tone (for example, stiff muscles), movement, and posture. Bone shape and structure adapt to the biomechanical environment (muscle forces, movement). Usually, bone adaptation is a beneficial process; however, in CP, bones adapt to abnormal biomechanics resulting in bone deformities, low bone density, and susceptibility to bone fracture. However, it is unknown whether the abnormal muscle forces, abnormal movements, or less physical activity are most responsible for the effects on the skeleton. There is strong evidence for low bone density in children with CP that cannot walk. Improvements in bone imaging technology now allow us to see the 3D bone structure using fast scanning times and low radiation doses. With this technology, we have the possibility to investigate why bone health is compromised in kids with CP that can walk. Our preliminary study shows smaller cross-sectional area of bones with less trabeculae in children with CP that can walk. A smaller cross-sectional area means that the bone is more susceptible to fracture. This study will investigate whether kids with diplegic CP (affecting both legs) have smaller bones as the severity of CP increases. We will also investigate whether kids with hemiplegic CP (only one leg affected) have smaller bones in the affected leg than the non-affected leg. We will investigate the relationship between bone parameters and biomechanics: walking pattern, forces produced by the legs during walking, and physical activity level. We seek to understand which aspects of movement in CP are associated with bone health. With this information, our future studies target the design of physical activity based treatments to improve bone health in CP. Our long-term goal is to develop knowledge, clinical tools and strategies to improve skeletal health in children with CP.