Abstract：
Individuals with chronic ankle instability (CAI) present muscular weakness and potential changes in the activation of the peroneus longus muscle, which likely explains the high recurrence of ankle sprains in this population. However, there is conflicting evidence regarding the role of the peroneus longus activity in CAI, possibly due to the limited spatial resolution of the surface electromyography (sEMG) methods (i.e., bipolar sEMG). Recent studies employing high-density sEMG (HD-sEMG) have shown that the peroneus longus presents differences in regional activation, however, it is unknown whether this regional activation is maintained under pathological conditions such as CAI. This study aimed to compare the myoelectric activity, using HD-sEMG, of each peroneus longus compartment (anterior and posterior) between individuals with and without CAI. Eighteen healthy individuals (No-CAI group) and 18 individuals with CAI were recruited. In both groups, the center of mass (COM) and the sEMG amplitude at each compartment were recorded during ankle eversion at different force levels. For the posterior compartment, the sEMG amplitude of CAI group was significantly lower than the No-CAI group (mean difference = 5.6% RMS; 95% CI = 3.4-7.6; p = 0.0001). In addition, it was observed a significant main effect for group (F1,32 = 9.608; p = 0.0040) with an anterior displacement of COM for the CAI group. These findings suggest that CAI alters the regional distribution of muscle activity of the peroneus longus during ankle eversion. In practice, altered regional activation may impact strengthening programs, prevention, and rehabilitation of CAI.
摘要：
患有慢性踝关节不稳定（CAI）的人表现出肌肉无力和腓骨长肌激活的潜在变化，这可能解释了该人群中踝关节扭伤的高复发率。然而,关于腓骨长活动在CAI中的作用有相互矛盾的证据，可能是由于表面肌电图(sEMG)方法的空间分辨率有限(即，双极sEMG)。最近采用高密度sEMG（HD-sEMG）的研究表明，腓骨长骨在区域激活方面存在差异，然而,尚不清楚这种区域激活是否在CAI等病理条件下保持。本研究旨在比较肌电活动，使用HD-sEMG，有和没有CAI的个体之间的每个腓骨长腔（前部和后部）。招募18名健康个体(无CAI组)和18名CAI个体。在这两组中,在踝关节外翻过程中,在不同的力水平下,记录每个隔层的质心(COM)和sEMG振幅.对于后舱，CAI组的sEMG振幅显著低于非CAI组(平均差异=5.6%RMS;95%CI=3.4-7.6;p=0.0001).此外,对于CAI组，COM前移组（F1,32=9.608；p=0.0040）观察到显着的主要作用。这些发现表明，CAI改变了踝关节外翻过程中长腓骨肌肉活动的区域分布。在实践中,改变区域激活可能会影响加强计划，预防,和CAI的康复。
