Effects of Functional Ankle Instability on Balance Recovery Strategy in Athletes

Purpose: Many research studies reported balance disorder as one of the most important consequences of Functional Ankle Instability. However, the Balance Recovery Strategy, which its deficiency can cause poor balance or secondary damages, has not been investigated in previous studies yet. The purpose of this article is to study the Balance Recovery Strategy in athletes with Functional Ankle Instability during jumping and landing. Methods: Fifteen male athletes with Functional Ankle Instability and 15 healthy male athletes were randomly assigned into two experimental and control groups, respectively. The subject’s Balance Recovery Strategy was observed by Surface Electromyography and during single-foot jumping and landing. In order to evaluate the Balance Recovery Strategy, the ratio of the total activity of the selected hip joint muscles to the total activity of the selected ankle muscles was evaluated. The Multivariate Analysis of Variance (MANOVA) was used to compare the Balance Recovery Strategy between the two groups. Significant level was considered as ≤0.05 in all the statistical analysis. Results: The results of the statistical tests showed a significant difference between the two groups with regard to the Electromyography activity of femur muscles and ankle muscles. That is, the subjects with Functional Ankle Instability are more likely to use the hip strategy than the ankle strategy to regain their balance. While the group of the healthy subjects used the ankle strategy. Conclusion: The transfer of the Balance Recovery Strategy from the ankle to the hip joint in the subjects of the Functional Ankle Instability group can be attributed to their proprioception deficit and a decrease in the ankle muscle strength. The reason is that proprioception deficiency can change the motor control programs in the Functional Ankle Instability group.