A morphological study on balance and explosive power in volleyball athletes with chronic ankle instability

The aim of this study is to investigate the effects of morphological features of the muscles involved in trunk stabilization (transversus abdominis, lumbar multifidus), muscles involved in lower limb explosive power (vastus lateralis, gastrocnemius), anteriotalofibular ligament on balance and explosive power in volleyball players with chronic ankle instability. A total of 28 female volleyball players, 12 healthy volleyball players (control group) aged 14-22 years, and 16 volleyball players with ankle instability were included in the study. The presence of instability was determined according to the inclusion criteria set by the International Ankle Consortium. In the first stage of the study, field tests were carried out after the questionnaires were questioned to determine the demographic information of the athletes and the presence of instability. Explosive power with the Y-Balance Test, the Squat Jump and Counter-Movement Jump test, and the lumbar stabilization with the Sahrmann's Core Stability Test were evaluated. Ultrasound measurements were performed to evaluate the muscle morphological characteristics of the athletes. Measurements were fascicle thicknesses for lumbar multifidus and transversus abdominis in both dynamic and static positions bilaterally; For the vastus lateralis and lateral gastrocnemius, fascicle thickness, fascicle length, pennation angle were recorded, and the thickness and length of the anteriortalofibular ligament were taken bilaterally. Morphological features of transversus abdominis, lumbar multifidus gastrocnemius lateralis and lumbar multifidus muscles were similar in both static and dynamic positions (p>0.05). Y-balance, core stability test results and jump heights were similar between groups (p>0.05). The explosive power results of the control group were higher than those of the instability group (p<0.05). In the instability group, the thickness of the vastus lateralis muscle of the unaffected side was moderately correlated with fascicle length in both positions and in the resting position, and explosive force (respectively r:0,53; r:0,636; r:0,594 p<0.05). A moderate correlation was found between lumbar multifidus muscle thickness and explosive strength at rest (p<0.05). A strong correlation was found between the lateral gastrocnemius pennation angle of the affected side and the posteromedial aspect of the balance test in dynamic position (r:0,515 p<0.05). Dynamic balance performances were found to be similar between the affected and unaffected extremities in the instability group (r: 0,738 p>0.05). Lumbar multifidus muscle thickness was found to be greater on the affected side in dynamic position (p<0.05). Morphological features of transversus abdominis, vastus lateralis, and lateral gastrocnemius muscles were found to be similar between the affected side and the unaffected side (p>0.05). Architectural features of transversus abdominis, vastus lateralis and lumbar multifidus muscles have changed in female volleyball players with instabilty, and skeletal muscles show adaptive changes; It was concluded that although instability reduces maximum contraction ability in minimum time, instability has no effect on dynamic balance performance, core stabilization and jump heights. According to these results, it is suggested that the presence of instability may affect the proximal structures and that chronic ankle instability should not be limited to the evaluation of the ankle and its surroundings. Keywords: Athletes, Ankle, Ultrasonography