Department of Rehabilitation Therapy, Graduate School, Yonsei University, Seoul, South Korea.
Laboratory of Kinetic Ergocise Based on Movement Analysis, Yonsei University, Wonju, South Korea.
Foot Ankle Int. 2020 Apr;41(4):479-485. doi: 10.1177/1071100719898464. Epub 2020 Jan 11.
Weakness of evertor strength is controversial in chronic ankle instability (CAI). Ankle evertor muscles are attached to the toe joints as well as to the metatarsal bone. Therefore, it is necessary to consider toe joint position for the measurement of evertor strength. The purpose of this study was to compare ankle evertor strength and muscle activity during eversion with and without toe flexion (TF) in individuals with CAI and individuals in a healthy group.
Fifteen subjects with CAI and 15 healthy subjects participated in this study. Isometric ankle evertor strength and muscle activity of the peroneus longus (PL), peroneus brevis (PB), and extensor digitorum longus (EDL) were measured during eversion with and without TF.
The results indicated a significant interaction effect in evertor strength ( = .03) and no significant interaction effect on EMG of the PL ( = .08), PB ( = .12), and EDL ( = .28). However, measurements of muscle activity of the PL and PB between eversion with and without TF revealed a significant difference in the CAI group ( < .01) and no significant difference in the healthy group (PL: = .07; PB: = .13).
The results indicated that subjects with CAI had increased EDL compensation and reduced selective activation of the PL and PB during eversion.
Our findings suggest that clinicians should consider the activation of EDL when training the evertor of patients with CAI.
慢性踝关节不稳（CAI）患者的外侧肌力量减弱存在争议。外侧肌附着于趾关节和跖骨。因此，在测量外侧肌力量时，有必要考虑趾关节的位置。本研究的目的是比较 CAI 患者和健康组在踝关节外翻时伴有和不伴有足趾背屈（TF）时的外侧肌力量和肌肉活动。
15 名 CAI 患者和 15 名健康受试者参与了本研究。在踝关节外翻时测量等长外侧肌力量和腓骨长肌（PL）、腓骨短肌（PB）和趾长伸肌（EDL）的肌电图。
结果表明，外侧肌力量存在显著的交互作用效应（ =.03），而 PL（ =.08）、PB（ =.12）和 EDL（ =.28）的肌电图无显著的交互作用效应。然而，在 CAI 组中，PL 和 PB 的肌肉活动测量值在伴有和不伴有 TF 的外翻之间存在显著差异（ <.01），而在健康组中则无显著差异（PL： =.07；PB： =.13）。
结果表明，CAI 患者在外翻时存在 EDL 代偿性增加和 PL 和 PB 选择性激活减少。
我们的研究结果表明，临床医生在训练 CAI 患者的外侧肌时，应考虑 EDL 的激活。
