Contribution of lower extremity joint moment on ground reaction force during walking in elderly and younger people

Antero-posterior ground reaction forces are the driving forces affecting walking speed. This study examined the relation between hip, knee, and ankle joint moment and the production of antero-posterior ground reaction forces during walking in the elderly and younger individuals. Forty elderly people, ≥65 years old, and 40 younger people, 20 to 29 years old, participated in this study. Gait analyses involved measurement of the ground reaction forces as well as calculation of hip, knee, and ankle joint moment. A stepwise linear regression analysis determined joint moment that can predict the amplitude of the antero-posterior ground reaction force. Extension moment during early stance of the knee was related to the posterior component of ground reaction force in elderly men, whereas hip and knee joint moments were related to the generation of the antero-posterior ground reaction forces in younger men. Moment of the hip and ankle were related to these forces in the elderly women. On the other hand, moment of the knee was related to generation of these forces in young women. Our results suggest differences between the elderly and the younger individuals with regard to the joints used for production of the antero-posterior ground reaction forces.