Abstract
Introduction: Ankle sprains are the most common and frequent injury in sports. Freeman demonstrated that an ankle injury would decreased the propriception sensitivity and result in poor postural steadiness in 1965. Further studies (Tropp, Ekstrand, & Gillquist, 1984; Tropp, Odenrick, & Gillquist, 1985) also showed similar results. More recent studies (Bernier, Perrin, & Rijke, 1997; Cornwall & Murrell, 1991) indicated that the injury of the ankle was not connection with the balance performance. Purpose: This study utilized the Kistler force plate and Biodex isokinetic dynamometer to testify the difference between subjects with functional instability and normal subjects. Methods: The ankles of 16 college-aged male subjects were tested in this study: 8 subjects with unilateral ankle sprain symptoms (I) and 8 with bilateral non injured healthy ankles (N).The Bioedx III isokinetic dynamometer was used to assess ankle proprioception function: active and passive position sense. The static balance ability was assessed by Kistler force plate in the form of mean radius of COP (center of pressure) distribution. Pearson correlation, independent t-test and one-way ANOVA analysis were used to exam the difference between different legs (left& right ankle in N; healthy & injured ankles in I). Results: 1, There was strong correlation between active ankle reposition sense and open/close static balance abilities. 2. The injured ankle had significant poor passive ankle reposition sense and open/close static balance abilities than healthy ankles. Otherwise, the passive ankle reposition sense and open eyes balance ability while having an injured ankle were also significantly poorer than the left & right ankle in N. Conclusions: This study clearly showed that an ankle sprain impaired the passive reposition sense and the close eyes static balance ability. The active ankle reposition sense has positive correlations with balance control. It was recommended that a rehabilitation program for sprained ankles should include proprioception training, especially in restoring the passive reposition sense. More studies are needed to examine the training or rehabilitation effects on the passive repositioning sense.