Objective

To determine the immediate effects of a varus unloader knee brace on lower-limb electromyographic activity in individuals with lateral knee osteoarthritis and valgus malalignment after anterior cruciate ligament reconstruction.

Methods

Electromyographic data were recorded in 19 individuals with lateral knee osteoarthritis and valgus malalignment after anterior cruciate ligament reconstruction during walking under three conditions: (i) no brace, (ii) unadjusted brace (no varus adjustment), and adjusted brace (varus adjustment). Variables of interest were statistically analyzed using repeated measures analysis of variance.

Results

There were no significant differences in muscle co-contraction between the three test conditions. The adjusted brace resulted in delayed offset of gluteus maximus (mean difference [95% CI]: 72 ms [24, 119]), and earlier onset of gluteus medius (59 ms [21, 97]) compared to no brace. The adjusted brace delayed onset of lateral gastrocnemius compared to no brace (53 ms [28, 78]) and the unadjusted brace (39 ms [7, 71]) and reduced average activation amplitude of gluteus maximus (−4 mV [−6, −1]) and lateral gastrocnemius (−9 mV [−16, −2]) compared to no brace.

Conclusions

The unloader brace did not produce significant changes in muscle co-contraction in individuals with lateral knee osteoarthritis and valgus malalignment after anterior cruciate ligament reconstruction. Significant changes in gluteal and gastrocnemius muscle activation timing and amplitude were observed, however, it is not clear whether these changes are of clinical importance.

中文翻译：

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前交叉韧带重建后，主要在外侧骨关节炎患者中，卸荷支架对下肢肌电图活动的影响。

目的

为了确定前交叉韧带重建后外侧膝关节骨关节炎和外翻畸形患者下颌内翻内支架对下肢肌电图活动的即时影响。

方法

在以下三种情况下行走期间在前十字韧带重建后19例患有外侧膝关节骨关节炎和外翻畸形的患者中记录了肌电数据：（i）无支撑，（ii）未经调节的支撑（无内翻调节）和经调节的支撑（内翻调节）。使用重复测量方差分析对感兴趣的变量进行统计分析。

结果

三种测试条件之间的肌肉共收缩没有显着差异。与没有支撑相比，调整后的支撑导致臀大肌延迟偏移（平均差异[95％CI]：72 ms [24，119]），以及臀中肌的发作较早（59 ms [21，97]）。与无支撑（53 ms [28，78]）和未调整的支撑（39 ms [7，71]）相比，调整后的腓肠肌延迟支具延迟发作和最大臀肌的平均激活幅度降低（−4 mV [-6， -1]和外侧腓肠肌（−9 mV [−16，-2]）与无支撑相比。

结论

在前交叉韧带重建后，具有外侧膝关节骨关节炎和外翻畸形的个体的卸除器支架的肌肉收缩没有明显变化。观察到臀肌和腓肠肌的激活时间和幅度发生了显着变化，但是尚不清楚这些变化是否具有临床重要性。