Department of Sports Medicine Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Sports Medicine Center, Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chiayi, Taiwan.
Sci Rep. 2020 May 26;10(1):8706. doi: 10.1038/s41598-020-65630-9.
This study aimed to exam the isokinetic shoulder rotator strength of professional volleyball athletes, by playing positions. This cross-sectional study included a total of 49 healthy male professional volleyball players. We measured the isokinetic strength of the external rotator (ER) and internal rotator (IR) muscles and compared the dominant and non-dominant shoulders at angular speeds of 60°/s and 180°/s. In ER, all positions of players had similar strength between the dominant shoulder and non-dominant shoulders. Conversely, all playing positions except libero had stronger strength in dominant shoulder than that in the non-dominant shoulder. The ER/IR ratio in the dominant shoulder was significantly lower only for the attacker (outside hitter and opposite) at 60°/s and 180°/s (P < 0.0001; P = 0.0028 respectively) and blocker at 60°/s (P = 0.0273) when compared with non-dominant shoulder. Furthermore, the attacker had a lower ER/IR ratio in the dominant shoulder than setter and libero at 60°/s and 180°/s. For elite volleyball players without injury, the dominant shoulder had a higher strength of internal rotation, causing the relative muscle imbalance than the non-dominant shoulder, especially for the attacker and blocker positions. Training program should be individualized for each playing position to improve the imbalanced shoulder.
本研究旨在通过位置检查专业排球运动员的等速肩部旋转肌力量。这项横断面研究共纳入 49 名健康的男性职业排球运动员。我们测量了外旋肌（ER）和内旋肌（IR）的等速力量，并比较了角速度为 60°/s 和 180°/s 时优势肩和非优势肩的肌肉力量。在 ER 中，所有运动员的位置在优势肩和非优势肩之间的力量相似。相反，除自由人外，所有位置的运动员在优势肩的力量都比非优势肩强。仅在 60°/s 和 180°/s 时（P<0.0001；P=0.0028）以及在 60°/s 时（P=0.0273），优势肩的 ER/IR 比值对于攻击者（外场手和对方）显著低于非优势肩（P<0.0001；P=0.0028），而在 60°/s 时（P=0.0273），对于阻挡者也是如此。此外，在 60°/s 和 180°/s 时，攻击者的优势肩的 ER/IR 比值低于二传手和自由人。对于没有受伤的精英排球运动员来说，优势肩的内旋力量更高，导致与非优势肩相比肌肉失衡更严重，尤其是对于攻击者和阻挡者。训练计划应针对每个位置进行个体化，以改善失衡的肩部。
