This came through my Medscape newsletter email in early September, but with the (late) arrival of PT Jr. to our home I didn’t get around to reading it. The authors also have a paper in the August issue of PTJ about the reliability of strength and power testing of the ankle, but here is the one that interested me more:
Webber SC, Porter MM. Effects of ankle power training on movement time in mobility-impaired older women. Med Sci Sports Exerc. 2010 Jul;42(7):1233-40.
PURPOSE: Reduced abilities to generate power put older adults at risk in situations that demand rapid movements. Slower movement times are associated with greater risk of falling and of being involved in a motor vehicle crash. The purpose of this study was to determine the effects of power training on foot movement time and, secondarily, on ankle strength and power in mobility-impaired older women.
METHODS: Fifty mobility-impaired women (70-88 yr) trained twice per week for 12 wk in one of three groups (weights, elastic bands, or placebo control). All groups performed seated warm-up exercises, followed by either concentric dorsiflexion (DF) and plantarflexion (PF) resistance exercises (weights and bands) performed “as fast as possible” or upper body flexibility exercises (control). Foot reaction/movement time and ankle DF and PF peak torque (30 degrees x s(-1)) and peak power (90 degrees x s(-1)) were measured before and after training.
RESULTS: Participants who trained with elastic bands demonstrated improvements in movement time (decreased by 24 ms or 12%, P = 0.003). All groups demonstrated improvements in DF and PF strength and power, which were not statistically different.
CONCLUSIONS: High-velocity/low-load (elastic bands) training improved movement time, which may have important implications in circumstances when rapid generation of torque is required (e.g., to avoid a fall or prevent a vehicle crash). Elastic bands are relatively inexpensive and provide a practical form of training that could be considered in programs designed for older adults with mobility limitations.
Photo credit: Bones of the foot and ankle, medial view with labels – Appendicular Skeleton Visual Atlas, page 32, originally uploaded by robswatski