Elderly nursing home and day care participants are less likely than young adults to approach imbalance during voluntary forward reaching.

The goal of this study was to determine whether differences exist between young and elderly adults in cautiousness or tendency to approach imbalance during a forward reaching task. Young (n = 26) and elderly (n = 25) adults participated in trials that required them to reach forward as quickly as possible to contact a target that moved back and forth, in and out of reach. "Voluntary reach" was calculated as the 75th percentile in reach distance over 20 trials. Measures were also acquired separately of "maximum attainable reach." Voluntary reach averaged 53% smaller in elderly than young subjects. This was due to differences in maximum attainable reach, and to increased cautiousness among elderly in approaching maximum attainable reach (voluntary reach averaged 65% +/- 23% of maximum attainable reach in elderly, and 95% +/- 5% in young; p < .001). Thus, cautiousness in approaching imbalance reduces voluntary reach in elderly but not young subjects. Furthermore, physical capacity (as measured by maximum attainable reach) and capacity utilization (as measured by voluntary reach) are independent predictors of reaching behavior among nursing home elderly.