Significant age and gender differences among healthy young and older adults in abilities to arrest forward momentum during turns away from, or stops before reaching, suddenly-appearing obstacles were reported by Cao et al. (1996a, 1996b). Thepresent study explored possible sources of those differences, by analyzing the whole-body-center-of-mass (CM) movement data. Age-and gender-group means of four parameters were calculated from the CM kinematics data: the time from the cue to react toreaching peak CM forward velocity (T{sub}1), and the values of CM acceleration (A1) and decelerations (D{sub}1 and D{sub}2) during three different post-cue response phases. A three-line-segment representation of the CM post-cue velocity was used toestimate the difference in response time needed (NRT) to arrest momentum resulting from the age and gender differences. The largest contributor to the age differences found in NRT was the age group increase in T{sub}1. Among the old adults, the genderdifference in D{sub}2 stands out as being almost totally responsible for the gender difference in NRT. The age and gender differences found may have arisen in part from age and gender differences in abilities to develop joint torque strengths rapidly.
展开▼
