The risk of falls in the elderly populations due to loss of balance increases with age. The aim of the present study is to analyse the relationship between lower limb explosive strength and the ability to maintain balance in two different samples of active young and elderly subjects.

Subjects included in the study were 8 elderly and 11 young volunteers, all of them physically active. Counter-movement jump tests and one-leg static balance tests using a foam-rubber surface were applied and measured by a force plate.

Height jumped was higher in the young, compared to the elderly volunteers (16.00±2.73 vs. 7.99±2.23% height; P<.001, respectively). The countermovement stiffness of the initial phase (P<.01) and the distance of the centre of pressures during static balance test was lower in the young group, compared to elderly (4.02±1.09 vs. 7.08±1.79cm2; P<.01, respectively). Moreover, the limits of the stability of the centre of pressures were higher in the elderly than in the young (168.50±32.26 vs. 32.70±37.54cm2; P<.01, respectively). No significant correlations were found between the strength and balance variables. In the elderly group, the countermovement descendent phase correlated with stiffness (r=–0.75; P<.05).

Although countermovement descendent phase of the jump was reduced, the active elderly maintained sufficient strength levels that could prevent falls. We believe that reduced stiffness during countermovement jumps and better postural balance can be obtained by increasing functional range of movement in their lower extremities.