Acute Effects Of Single- Versus Double-Leg Postactivation Potentiation On Postural Balance Of Older Women: An Age-Matched Controlled Study

Aims: To compare the postactivation potentiation effects of isometric contraction until failure in double- and single-leg tasks on older women's balance. Methods: The one-legged balance test was performed before and immediately after a rise-to-toes task until the task failure. Older women were divided into two groups: a group performed the task with double leg (n = 43) and the other group with single-leg support (n = 55). Results: The single-leg group showed slower velocity of sway post rise-to-toes task (pre = 4.02 +/- 1; post = 3.78 +/- 1.15 m/s; p = .04) without differences for the center of pressure path length (pre = 79 +/- 21; post = 75 +/- 23 cm; p = .08). In the double-leg group, faster velocity of sway (pre = 4 +/- 1.22; post = 4.25 +/- 1.13; p = .03) and increased center of pressure path length (pre = 80 +/- 24; post = 85 +/- 23 cm; p = .03) were observed after the task. Conclusions: The single-leg group showed improved balance outcomes due to postactivation potentiation, while the double-leg group showed worsened balance consistent with muscle fatigue.