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.
Ilha G. Fernandes, Matheus A. Souza, Matheus L. Oliveira, Bianca Miarka, Michelle A. Barbosa, Andreia C. Queiroz, and Alexandre C. Barbosa
Edgar R. Vieira, Ruth Tappen, Sareen S. Gropper, Maria T. Severi, Gabriella Engstrom, Marcio R. de Oliveira, Alexandre C. Barbosa, and Rubens A. da Silva
The objective of this pilot study was to evaluate a 6-month exercise program completed by 10 older Caribbean Americans. Assessments were done at baseline and 3 and 6 months, and included walks on an instrumented mat at preferred speed, and during street crossing simulations with regular (10 s) and reduced time (5 s). There were no significant differences on preferred walking speed over time. Differences between the street crossing conditions were found only at 6 months. Significant changes over time among the assessments were found only during street crossing with reduced time. Street crossing with reduced time was the only walking condition sensitive to capture changes associated with participating in the exercise program. There was a significant increase in dorsiflexion strength overtime. At 6 months it was significantly higher than at baseline and 3 months. The program was feasible, acceptable, and had some positive effects on walking, knee flexion, and dorsiflexion strength.