Study design

Cross-sectional study.

Objectives

A spinal cord injury (SCI) can compromise the ability to maintain sufficient balance control during activities in an upraised position. The objective of the study was to explore the relationship between balance control and muscle strength and muscle activation in the lower extremities in persons with incomplete SCI (iSCI).

Setting

Sunnaas Rehabilitation Hospital, Norway.

Methods

Thirteen men and two women with iSCI and 15 healthy, matched controls were included. Performance of the Berg Balance Scale (BBS) short version (7 items) was used to indicate balance control. Maximal voluntary contraction (MVC) was performed to measure isometric muscle strength in thigh muscles (knee extension/flexion), while surface electromyography (EMG) was measured from M. Vastus Lateralis and M. Biceps Femoris. The relative activation of each muscle during each of the BBS tasks was reported as the percentage of the maximal activation during the MVC (%EMG_max).

Results

The iSCI participants had a significantly lower BBS sum score and up to 40% lower muscle strength in knee- flexion and extension compared to the matched healthy controls. They also exhibited a significantly higher %EMG_max, i.e. a higher muscle activation, during most of the balance tests. Univariate regression analysis revealed a significant association between balance control and mean values of %EMGmax in Biceps Femoris, averaged over the seven BBS tests.

Conclusions

The participants with iSCI had poorer balance control, reduced thigh muscle strength and a higher relative muscle activation in their thigh muscles, during balance-demanding activities.

中文翻译：

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不完全性脊髓损伤患者平衡控制能力与大腿肌力和肌肉活动的关系

学习规划

横断面研究。

目标

脊髓损伤 (SCI) 会影响在高位活动期间保持足够平衡控制的能力。该研究的目的是探讨不完全性脊髓损伤 (iSCI) 患者下肢的平衡控制与肌肉力量和肌肉激活之间的关系。

环境

挪威桑纳斯康复医院。

方法

包括 13 名患有 iSCI 的男性和 2 名女性以及 15 名匹配的健康对照者。Berg平衡量表（BBS）简版（7个项目）的表现用于指示平衡控制。进行最大随意收缩（MVC）来测量大腿肌肉的等长肌力（膝关节伸展/屈曲），同时测量股外侧肌和股二头肌的表面肌电图（EMG）。每个 BBS 任务期间每块肌肉的相对激活被报告为 MVC 期间最大激活的百分比 (%EMG _max )。

结果

与匹配的健康对照组相比，iSCI 参与者的 BBS 总分显着较低，膝关节屈曲和伸展的肌肉力量低 40%。在大多数平衡测试中，他们还表现出明显更高的 %EMG _{max ，即更高的肌肉激活度。}单变量回归分析显示，平衡控制与股二头肌 %EMGmax 平均值（七次 BBS 测试的平均值）之间存在显着相关性。

结论

在需要平衡的活动中，患有 iSCI 的参与者的平衡控制能力较差，大腿肌肉力量降低，大腿肌肉的相对肌肉激活程度较高。