The effect of ankle disk training on muscle reaction time in subjects witha history of ankle sprain

The purpose of this study was to determine whether 8 weeks of ankle disk tr aining alters ankle muscle onset latency of patients with a history of late ral ankle sprain. The training was completed by eight minimally symptomatic subjects with a history of nonrehabilitated, unilateral, inversion ankle s prain sustained between 6 and 16 months before entry into the study. Ankle inversion perturbations monitored by fine-wire electromyography were perfor med in four lower extremity muscles (anterior tibialis, posterior tibialis, peroneus longus, and flexor digitorum longus) of all subjects on both the injured (experimental) and noninjured (control) legs. Testing was performed at study entry and after 8 weeks of ankle disk training on the previously injured ankle. Results revealed a statistically significant decrease in the anterior tibialis onset latency in both the experimental (67.6 +/- 20.3 to 51.7 +/- 17.6) and control (65.5 +/-9.8 to 53.8 +/- 23.7) ankles after the training period. These findings indicate that muscle onset latency decreas es in specific ankle muscle groups after ankle disk training in previously injured ankles. Both the experimental and control ankles demonstrated a sig nificant change, which raises the question as to whether a proprioceptive c ross-training effect occurred.