Hobara Hiroaki, Hashizume Satoru, Kobayashi Yoshiyuki
Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology, Tokyo, Japan.
Open Access J Sports Med. 2017 Apr 26;8:107-112. doi: 10.2147/OAJSM.S132275. eCollection 2017.
During human movement, the leg can be represented as a mechanical spring, with its stiffness potentially contributing to sports performance and injury prevention. Although many individuals perform athletic activities with joint stabilizers, little is known about the effects of prophylactic lower extremity braces on leg stiffness. The objective of this study was to investigate the effect of ankle and/or knee braces on leg stiffness measured during one-legged hopping at a range of frequencies. Thirteen male participants performed one-legged hopping with their dominant leg at frequencies of 2.2, 2.6, and 3.0 Hz. All participants were randomly tested under the following four brace conditions: 1) no brace (control), 2) prophylactic ankle brace, 3) prophylactic knee brace, and 4) prophylactic ankle and knee braces. Based on a spring-mass model, leg stiffness was calculated using data from an accelerometer. It was found that leg stiffness increased with increasing hopping frequency for each brace condition. However, there were no significant differences in leg stiffness among the four brace conditions at the three hopping frequencies. Since some level of leg stiffness is needed for optimal athletic performance and training, these results suggest that ankle and knee braces do not significantly interfere with dynamic hopping activities.
在人体运动过程中，腿部可被视为一个机械弹簧，其刚度可能对运动表现和损伤预防有影响。尽管许多人在进行体育活动时会使用关节稳定器，但对于预防性下肢支具对腿部刚度的影响却知之甚少。本研究的目的是调查脚踝和/或膝盖支具对在一系列频率下单腿跳跃过程中测量的腿部刚度的影响。13名男性参与者用其优势腿以2.2、2.6和3.0赫兹的频率进行单腿跳跃。所有参与者在以下四种支具条件下进行随机测试：1）不使用支具（对照），2）预防性脚踝支具，3）预防性膝盖支具，4）预防性脚踝和膝盖支具。基于弹簧质量模型，使用加速度计的数据计算腿部刚度。结果发现，在每种支具条件下，腿部刚度都随着跳跃频率的增加而增加。然而，在三个跳跃频率下，四种支具条件之间的腿部刚度没有显著差异。由于最佳运动表现和训练需要一定程度的腿部刚度，这些结果表明脚踝和膝盖支具不会显著干扰动态跳跃活动。
