In recent years, the relationship between healthy life expectancy and exercise has been shown, and the same is also reported for the disabilities. However, we have not yet found any reports on the effects of exercise in children with lower extremity amputations. In this study, we had followed a seven-year-old boy who had undergone right knee rotationplasty for the Ewing's sarcoma, and studied the changes in his athletic abilities, bone density, and body composition with the use of a running-specific prosthesis (RSP). After becoming independent on walking with a daily-use prosthesis, he started using the RSP during exercise such as running. We measured the above parameters before the introduction of RSP, then again after one year use of the RSP. The results showed positive changes in all measurements: increased motor strength around hip, longer time on one leg standing test, increased one leg jump, faster walking speed, wider stride, improved bone density, and improved body compositions. The use of RSP's along with daily-use prostheses for children in their growth period may have favorable effects on their athletic abilities, bone densities, and body compositions.

In recent years, the relationship between healthy life expectancy and exercise has been shown, and the same is also reported for the disabilities. However, we have not yet found any reports on the effects of exercise in children with lower extremity amputations. In this study, we had followed a seven-year-old boy who had undergone right knee rotationplasty for the Ewing's sarcoma, and studied the changes in his athletic abilities, bone density, and body composition with the use of a running-specific prosthesis (RSP). After becoming independent on walking with a daily-use prosthesis, he started using the RSP during exercise such as running. We measured the above parameters before the introduction of RSP, then again after one year use of the RSP. The results showed positive changes in all measurements: increased motor strength around hip, longer time on one leg standing test, increased one leg jump, faster walking speed, wider stride, improved bone density, and improved body compositions. The use of RSP's along with daily-use prostheses for children in their growth period may have favorable effects on their athletic abilities, bone densities, and body compositions.