Stepping performance during obstacle clearance in women: Age differences and the association with lower extremity strength in older women

OBJECTIVE: To compare stepping performance during obstacle clearance in you nger and older women, and to examine the relationship between lower extremi ty strength and stepping performance during obstacle clearance in older wom en. DESIGN: Correlational study. SETTING: A small community. PARTICIPANTS: Twenty-four older women (mean age = 74.4), and 16 younger wom en (mean age = 20.7). The older participants lived independently in the com munity and were able to walk unaided. MEASUREMENTS: Lower extremity muscle strength, measures of stepping perform ance including reaction time, movement time, extent of obstacle clearance, time to clear obstacle, among others. MAIN RESULTS: The older women were far slower in stepping than the younger women. Toe trajectories differed between older and younger women during the initial portion of the step. The younger women tended to lift the toe stra ight up, whereas the older women tended to move the toe backward, away from the obstacle, passing farther from the obstacle when the toe cleared the o bstacle height. There was little, if any, association between relative lowe r extremity strength and stepping performance during obstacle clearance in older women. CONCLUSIONS: Dramatic differences in the speed of volitional stepping perfo rmance were found between younger and older women. Among the older women, l ower extremity strength was not related to volitional stepping performance.