Isokinetic performance of ankle evertor and invertor muscles in adolescent female volleyball athletes

Abstract Aims: This study aimed to analyze the muscular performance of evertor and invertor ankle muscles of adolescent volleyball athletes. Methods: The information provided by database concerning the isokinetic evaluation of ankle muscles from 20 female volleyball players between the ages of 14-17 years old were analyzed. The isokinetic dynamometer was used in a concentric-concentric mode for the ankle evertor and invertor muscles at angular velocities of 60°/s, and 180°/s. Results: Seven athletes had suffered ankle sprains (6 affected the non-dominant limb and all were lateral ankle sprain) in the one year prior to the isokinetic evaluation. The isokinetic results demonstrated that the mean peak torque values for eversion of the non-dominant limb were significantly lower in comparison to the dominant limb at 60°/s. Moreover, although no difference was observed in the average values of the evertor/invertor ratio between the limbs, the ratios were below the values suggested by the literature. Conclusion: We believe that although the athletes reported no ankle injury and no pain in the previous assessment month, the isokinetic results of the non-dominant limb seemed to be directly related to previous ankle sprains injuries in inversion of this limb. The athletes had similar results to those of subjects clinically diagnosed with ankle joint instabilities despite their being active in sports at the moment of the assessment.

摘要
研究目的：本研究旨在分析青少年排球运动员踝关节外翻肌与内翻肌的肌肉功能表现。
研究方法：本研究对数据库收录的20名14~17岁女子排球运动员的踝关节肌肉等速评估（isokinetic evaluation）数据进行了分析。采用等速测力系统（isokinetic dynamometer）以向心-向心模式，分别以60°/s、180°/s的角速度对受试者踝关节外翻肌与内翻肌开展测试。
研究结果：共有7名运动员在本次等速评估前1年内发生过踝关节扭伤，其中6例累及非优势侧肢体，且均为外侧踝关节扭伤。等速测试结果显示，在60°/s角速度下，非优势侧肢体的外翻平均峰力矩值显著低于优势侧肢体。此外，尽管双侧肢体的外翻肌/内翻肌比值无显著组间差异，但该比值均低于现有文献推荐的参考值。
研究结论：本研究认为，尽管受试运动员在本次评估前1个月自述无踝关节损伤及疼痛症状，但非优势侧肢体的等速测试结果似乎与该肢体既往内翻型踝关节扭伤直接相关。尽管受试运动员在评估时仍活跃于体育运动中，但其测试结果与临床诊断为踝关节不稳的受试者表现相近。