Mino Soushi, Kosaka Takahiro, Kubo Keitaro
Department of Life Science, The University of Tokyo, Meguro, Tokyo, Japan.
Sports Biomech. 2025 May;24(5):1414-1428. doi: 10.1080/14763141.2023.2275254. Epub 2023 Nov 3.
In some sporting events (e.g., long-distance running), the ability to maintain joint stiffness is considered an essential physical ability. However, the determinants of joint stiffness endurance remain unclear. This study aimed to examine the effects of muscular endurance and tendon extensibility on joint stiffness endurance. Thirteen males performed the fatigue task (5 sets of 50 hopping). Ankle joint stiffness during drop jump was measured before and after fatigue task. The maximum number of repetitions at 30% of one repetition maximum for plantar flexion was measured as muscular endurance. Maximal elongation of the Achilles tendon was measured during ramp (with a low strain rate of tendon) and ballistic (with a high strain rate of tendon) contractions as tendon extensibility. Joint stiffness significantly decreased by 7.5% after the fatigue task ( = 0.033). The maximum number of repetitions at 30% of 1RM (79.6 ± 48.7 repetitions) was not significantly correlated with the relative change in joint stiffness ( = 0.283, = 0.348). The maximal elongation of the Achilles tendon measured during ramp and ballistic contractions were not significantly associated with the relative change in joint stiffness ( = 0.326, = 0.277 for ramp contraction; = 0.438, = 0.135 for ballistic contraction). These results suggest that muscular endurance and tendon extensibility were unrelated to joint stiffness endurance.
在一些体育赛事（如长跑）中，保持关节僵硬的能力被视为一项重要的身体能力。然而，关节僵硬耐力的决定因素仍不清楚。本研究旨在探讨肌肉耐力和肌腱伸展性对关节僵硬耐力的影响。13名男性进行了疲劳任务（5组，每组50次单脚跳）。在疲劳任务前后测量了纵跳时的踝关节僵硬程度。将跖屈一次最大重复量的30%时的最大重复次数作为肌肉耐力进行测量。在斜坡（肌腱应变率低）和弹道（肌腱应变率高）收缩过程中测量跟腱的最大伸长量作为肌腱伸展性。疲劳任务后关节僵硬程度显著降低了7.5%（=0.033）。1RM的30%时的最大重复次数（79.6±48.7次重复）与关节僵硬程度的相对变化无显著相关性（=0.283，=0.348）。在斜坡和弹道收缩过程中测量的跟腱最大伸长量与关节僵硬程度的相对变化无显著关联（斜坡收缩时=0.326，=
