Effects of 4 Weeks of Elastic-Resistance Training on Ankle-Evertor Strength and Latency
Context:Several researchers have suggested that improving evertor strength and peroneus longus reaction time may help alleviate the symptoms of chronic ankle instability and reduce the rate of recurrent ankle sprains.Objectives:To determine the effectiveness of a 4-wk elastic-resistance exercise-training program on ankle-evertor strength and peroneus longus latency in subjects with and without a history of ankle sprains (HAS).Design:Randomized controlled clinical trial.Participants:40 subjects (20 male, 20 female; 20 HAS, 20 healthy). Ten subjects (5 male and 5 female) from each of the HAS and healthy groups were randomly assigned to exercise or control groups.Interventions:4-directional elastic-resistance exercise training 2 times/wk for 4 wk.Main Outcome Measures:Ankle-evertor strength and peroneal muscle latency after sudden inversion were measured before training, after 4 wk of training, and 4 wk posttraining.Results:Four weeks of elastic-resistance exercise training did not elicit significant changes in 1-repetition-maximum ankle-evertor strength between the exercise and control groups (P = .262), HAS and healthy groups (P = .329), or males and females (P = .927). Elastic-resistance exercise training did not elicit significant changes in peroneus longus muscle latency between the exercise and control groups (P = .102), HAS and healthy groups (P = .996), or males and females (P = .947).Conclusions:The 4-wk elastic-resistance exercise training had no effect on ankle-evertor strength and reflex latency of the peroneus longus after unexpected ankle inversion.