Department of Rehabilitation, Faculty of Health Science, Hokkaido Chitose College of Rehabilitation, 2-10 Satomi, Chitose, Hokkaido, 066-0055, Japan.
Department of Sport Science and Research, Japan Institute of Sports Sciences (JISS), Tokyo, Japan.
J Med Ultrason (2001). 2023 Oct;50(4):561-570. doi: 10.1007/s10396-023-01360-5. Epub 2023 Aug 28.
Individuals with chronic ankle instability (CAI) have deficits in closed kinetic chain dorsiflexion that may perpetuate injury. Determining the characteristics of muscle stiffness in the plantar flexors of individuals with CAI may help in developing appropriate treatments. We aimed to highlight the characteristics of static muscle stiffness in ankle plantar flexor muscles during the passive dorsiflexion of the ankle joint in individuals with CAI.
A total of 30 patients were included in the study based on the International Ankle Consortium criteria. The patients were categorized evenly into healthy, coper, and CAI groups (i.e., 10 patients in each group). After measuring the dorsiflexion range of motion (non-weight-bearing/weight-bearing) of the ankle joint, the static muscle stiffness measurements of the medial gastrocnemius, lateral gastrocnemius, soleus, and peroneus longus were obtained. The measurements were performed during the knee joint's extension and 50° flexion and passive dorsiflexion between the range of 40° plantar flexion and 20° dorsiflexion.
The dorsiflexion range of motion of the CAI group was significantly smaller than that of the healthy and coper groups in the weight-bearing position. No interaction was observed for muscle stiffness in both the knee flexion and extension positions, and no significant differences were identified among the three groups. The shear modulus of the soleus at 20° ankle dorsiflexion with knee flexion had a significant negative correlation with the weight-bearing range of motion of the ankle.
The limitation in the weight-bearing dorsiflexion range of motion in CAI was largely due to factors other than the increased elasticity of the ankle plantar flexor muscles.
慢性踝关节不稳定（CAI）患者在闭合式动力链背屈时存在缺陷，这可能会使损伤持续存在。确定 CAI 患者跖屈肌的肌肉僵硬特征可能有助于制定适当的治疗方法。我们旨在强调 CAI 患者在踝关节被动背屈期间，踝关节跖屈肌的静态肌肉僵硬特征。
根据国际踝关节联合会的标准，共有 30 名患者被纳入研究。患者被平均分为健康组、代偿组和 CAI 组（即每组 10 名患者）。在测量踝关节背屈活动范围（非负重/负重）后，对内侧比目鱼肌、外侧比目鱼肌、跟腱和腓肠肌进行静态肌肉僵硬测量。测量在膝关节伸展和 50°屈曲以及被动背屈期间进行，背屈范围为 40°跖屈至 20°背屈。
CAI 组在负重位时的背屈活动范围明显小于健康组和代偿组。在膝关节弯曲和伸展位置，肌肉僵硬均无交互作用，三组之间也无显著差异。在膝关节弯曲 20°背屈时，跟腱的剪切模量与踝关节负重活动范围呈显著负相关。
CAI 患者负重背屈活动范围的限制主要归因于踝关节跖屈肌弹性增加以外的因素。
