Relation of age and passive properties of an ankle dorsiflexion stretch to the timed one-leg stance test in older women.

26 older women (aged 65 to 89 years) participated in this study, which examined the relationship of age and passive properties of a dorsiflexion stretch of the calf muscle-tendon unit with one-leg stance times. Age was negatively correlated with the time stance (r = -.75). The maximal passive dorsiflexion angle, length extensibility, maximal passive dorsiflexion torque, and the area under the passive curve (total passive elastic energy) were all positively correlated with the stance time (range: r = .49-.69). A multiple regression analysis indicated age was the best predictor of the times. Age and the maximal passive dorsiflexion angle together accounting for 71% of the variance in the time (R = .84, R(2) = .71). The addition of the remaining passive measurements did not improve the variance accounted for in the one-leg stance time. The results indicated that the maximal ankle dorsiflexion range of motion may be important for one-leg standing balance of older women. Accordingly, stretching exercises designed to increase the maximal dorsiflexion angle may have a role for maintaining or improving their standing balance.