The effects of chronic ankle instability on balance, lower extremity functional movement and hip muscles strength in adolescent volleyball players

ABSTRACT AKOĞLU, A.S. The Effects of Chronic Ankle Instability on Balance, Lower Extremity Functional Movement and Hip Muscles Strength in Adolescent Volleyball Players. Hacettepe University, Institute of Health Sciences, Sports Physiotherapy Program, Master of Science Thesis, Ankara 2018 This study was planned to investigate the effect of chronic ankle instability (CAI), which is common in volleyball players, on balance, lower extremity functional movements and strength of hip muscles in sports. The study was performed with 23 female volleyball players with CAI and 23 asymptomatic individuals of similar age and body mass index. Hip flexion, extension, abduction, adduction internal and external rotation MVI (maximal voluntary isometric) muscle strengths were measured with Lafayette Manual Muscle Tester (Lafayette Instruments), lower extremity functional movement quality was assessed by the functional movement screen lower extremity (FMS-LE) parameter, static balance was measured with The SportKAT 2000 instrument balance index (BI), dynamic balance was measured with Y-balance test and Optojump (Microgate, Italy) instrument was used to measure jump heights. As a result, hip flexion muscle strength was found lower in CAI group than in control group (p˂0.05). There were no differences between the two groups in hip extension, abduction, adduction, internal and external rotation muscle strength (p˃0.05). The FMS-LE score was found lower in the CAI group (p=0.001). Static balance, dynamic balance and jump heights results were found to be similar in the CAI and control group (p˃0.05). When the results of the injured and non-injured side of CAI subjects were compared, hip muscle strength, static and dynamic balances were found similar between groups. In this study, it was found that the hip flexion muscle strength decreased and the quality of the hip functional movements were affected in the volleyball players with CAI. It has been concluded that evaluation and training strategies for hip joints should be taken into account in the training and rehabilitation of athletes with CAI. There is requiring further studies that examine the hip functional movements more extensively. Key Words: Ankle, muscle strength, lower extremity.