Okada Takashi, Hakkaku Takayoshi, Iwai Kazunori, Nakazato Koichi
Faculty of Sport Science, Nippon Sport Science University, Setagaya-ku, Japan.
Department of Judo therapy, Japan Health and Medical College, Taito-ku, Japan.
Sports Med Int Open. 2020 Dec 16;5(1):E14-E21. doi: 10.1055/a-1303-2741. eCollection 2021 Jan.
Trunk muscle strength (TMS), especially rotator, is an important factor for both athletic performance and injury risks in judokas. However, the characteristics of TMS that depend on weight categories are still unclear. Although inadequate TMS might cause low back pain (LBP), the relationship between these two variables is not fully understood. In this study, weight category-dependent TMS and its relationship with LBP was investigated in Japanese judokas. The subjects were 66 male collegiate judokas, who were classified into the lightweight (N=14), middleweight (N=29) or heavyweight (N=23) category. The peak torques of extensor, flexor and rotator muscles were measured. The LBP group and non-LBP group were defined by questionnaire. TMS (normalized by body weight) in the heavier weight category showed a lower tendency in comparison with other categories, except for rotator strength. Significant differences were observed in the extensors (90 and 120 °/s; P<0.05) and flexors (60, 90 and 120 °/s; P<0.05). The LBP group (N=9) only showed significantly lower extensor (60 °/s; P<0.05) and right-rotator (60 °/s; P<0.01) strength in the heavyweight category compared with the non-LBP group (N=14). The relative TMS of judokas decreased in the heavyweight category, except for trunk rotator strength. Notably, low trunk extensor and rotator strengths are risk factors for LBP in heavyweight judokas.
躯干肌肉力量（TMS），尤其是旋转肌力量，是影响柔道运动员运动表现和受伤风险的重要因素。然而，依赖体重级别的TMS特征仍不明确。尽管TMS不足可能导致腰痛（LBP），但这两个变量之间的关系尚未完全了解。在本研究中，对日本柔道运动员进行了体重级别相关的TMS及其与LBP关系的调查。受试者为66名男性大学生柔道运动员，分为轻量级（N = 14）、中量级（N = 29）或重量级（N = 23）。测量了伸肌、屈肌和旋转肌的峰值扭矩。通过问卷调查定义LBP组和非LBP组。除旋转肌力量外，较重体重级别的TMS（按体重标准化）与其他级别相比有降低趋势。在伸肌（90和120°/s；P < 0.05）和屈肌（60、90和120°/s；P < 0.05）中观察到显著差异。与非LBP组（N = 14）相比，LBP组（N = 9）在重量级中仅显示伸肌（60°/s；P < 0.05）和右旋转肌（60°/s；P < 0.01）力量显著降低。除躯干旋转肌力量外，柔道运动员的相对TMS在重量级中降低。值得注意的是，低躯干伸肌和旋转肌力量是重量级柔道运动员LBP的危险因素。
