Age-related differences in postural control in humans in response to a sudden deceleration generated by postural disturbance

Age-related differences in postural control in response to a relatively lar ge deceleration resulting from postural disturbance were investigated in ei ght normal elderly men (age range 67-72 years) and eight young men as contr ols (age range 19-22 years) using a moving platform. Data were obtained for the hip, knee and ankle angles, position of the centre of foot pressure (C FP), head acceleration, and muscle activity of the leg muscles. The elderly subjects had slower and larger ankle and hip joint movements, and CFP disp lacement in response to the disturbance compared to the young controls. The elderly subjects also had a delayed occurrence, and greater magnitude of p eak acceleration of head rotation than did the young subjects. For the elde rly subjects, the CFP was closely related to angular changes in the hip joi nt movement., but not to those of the ankle and knee joint movements. For t he young subjects, on the other hand, the CFP was significantly correlated with angular change in the ankle joint. Cocontraction of the tibialis anter ior and gastrocnemius muscles was observed in the elderly subjects. The res ults indicated that a movement pattern for postural correction in the elder ly adults was different from that of the young adults. The elderly relied m ore on hip movements while the young controls relied on ankle movements to control postural stability.