The aim of the study is to investigate the effects of a 4-week, unilateral balance exercise training program on bilateral balance and explosive power in athletes with chronic ankle instability. The participants were randomly divided into Stable Ankle Training Group (SG) (n=9), Unstable Ankle Training Group (UG) (n=9) and control group (CG) (n=10). The balance exercise training program was administered for only the stable ankle of athletes in SG and only the unstable ankle of athletes in UG, twice a week and for a 4-week duration.

The aim of the study is to investigate the effects of a 4-week, unilateral balance exercise training program on bilateral balance and explosive power in athletes with chronic ankle instability (CAI). The study included 28 volunteer athletes with a history of CAI who registered as a team player at Yeditepe University Culture and Sports Directorate February 2019 - June 2019. The severity of functional ankle instability of all the athletes was assessed by the Cumberland Ankle Instability Tool (CAIT). Functional limitations of the athletes with CAI were evaluated by Foot and Ankle Ability Measure Activity of Daily Living Subscale (FAAM-ADL) and Sports Subscale (FAAM-S). Balance Error Scoring System (BESS) was used to determine the static balance performance of athletes. Dynamic balance was evaluated by the Y Balance Test (YBT). Sport performance including vertical jumping and hopping was assessed with Single-Legged Countermovement Jump (CMJ) Test, Figure-of-Eight Hop Test, and Side Hop Test. The athletes were randomly divided into Rehabilitation for the Stable Ankle Group (SG) (n=9), Rehabilitation for the Unstable Ankle Group (UG) (n=9) and Control Group (CG) (n=10). Athletes in SG and UG were included balance exercise training program. The balance exercise training program was administered for only the stable ankle of athletes in SG and only the unstable ankle of athletes in UG, twice a week and for a 4-week duration.

Inclusion Criteria:

• Participating in the study on a voluntary basis
• Athletes with 18-25 years old
• Being a player in one of the basketball, volleyball, and handball team sports
• Athletes with a history of at least 2 significant lateral ankle sprains which were classified as a second degree and related to inflammatory symptoms (pain, swelling)
• The self-reported sensation of giving away and instability at the injured ankle confirmed by the Cumberland Ankle Instability Tool with a score ≤25
• Recurrent lateral ankle sprain episodes of the injured ankle occurred at least 12 months
• The self-reported function of the injured ankle confirmed by Foot and Ankle Ability Measure with a score <90% from activities of daily living subscale and <80% from sport subscale.

Exclusion Criteria:

• A history of surgery to the musculoskeletal structures in either lower extremity
• A history of a fracture in either lower extremity necessitating realignment
• Acute injury of musculoskeletal structures of other joints of the lower extremity in the previous 3 months affecting joint function and integrity
• Presence of bilateral ankle instability
• Balance or vestibular disorder