ABSTRACT
Objective To evaluate how proprioception affect ankle stability through comparing angle position awareness and peroneus reaction time between chronic ankle lateral instability patients and healthy controls.Methods A total of 51 participants were recruited into an experimental group of 21 patients with chronic ankle lateral instability (17 males,aged 31.6±2.6) and a control group of 30 healthy counterparts (24 males,aged 34.2±2.3).All the participants were asked to reoccur passive ankle position under the angular velocity at 2 degree per second when they were resting with non-weight bearing in their recruited ankles.The muscle reaction time (MRT)of peroneus longus(PL) and peroneus brevis (PB) in all the recruited ankles was measured during sudden ankle inversion both with and without ankle protective brace wearing.Results The difference between angle recurrence and the target angle (ankle inversion 20° and 30°) was significantly higher (P＜0.05) in the experimental group compared to the control group.The average MRTs of PL and PB were also significantly longer (P＜0.05) in the experimental group than the control group,whether wearing ankle protective braces or not.However,within both groups,no significant differences of PL and PB's MRT were identified between brace wearing and no brace (P＞0.05).Conclusions In patients with chronic lateral ankle instability,the position awareness decreases and the reaction time of peroneus is prolonged.Ankle braces can provide mechanical protection to the injured joints,but cannot promote MRT significantly.