Collins Amber, Blackburn J Troy, Olcott Chris, Yu Bing, Weinhold Paul
Department of Biomedical Engineering, University of North Carolina, Chapel Hill, USA.
Clin Biomech (Bristol). 2011 Oct;26(8):853-8. doi: 10.1016/j.clinbiomech.2011.04.011. Epub 2011 Jun 2.
Increased impulsive loading and muscle co-contraction during gait have been observed in individuals with knee osteoarthritis. Proprioceptive deficits in this population may contribute to these effects. Proprioception has been shown to improve with the combination of stochastic resonance electrical stimulation and a knee sleeve in knee osteoarthritis. Our goal was to determine whether stochastic resonance stimulation combined with a knee sleeve would decrease impulsive loading rates and muscle co-contraction during gait in knee osteoarthritis.
Gait kinetics, kinematics and muscle activity were assessed during walking in subjects with knee osteoarthritis during three different conditions: no stochastic resonance/no sleeve (control), stochastic resonance at 75% threshold/sleeve, and no stochastic resonance/sleeve. Loading rates were calculated from the ground reaction force. Muscle co-contraction was calculated from the ratio of vastus lateralis to lateral hamstring activity. Differences between conditions were assessed using a repeated measures analysis of variance (P<0.05).
The 75% threshold/sleeve and sleeve only conditions resulted in increased knee flexion at contact and reduced loading rates compared to the control condition (P<0.05). However, these measures did not significantly differ between the 75% threshold/sleeve and sleeve only conditions. Muscle co-contraction was found to decrease with the 75% threshold/sleeve condition compared to the other conditions.
Increased knee flexion and decreased loading rates may be a result of proprioceptive improvements resulting from the sleeve or sleeve/stimulation combination. The stochastic resonance stimulation did not demonstrate an ability to enhance the effects of the sleeve with the exception of reductions in muscle co-contraction.
在膝关节骨关节炎患者中，已观察到步态过程中冲动负荷增加和肌肉共同收缩。该人群的本体感觉缺陷可能导致这些影响。在膝关节骨关节炎中，随机共振电刺激与护膝相结合已显示可改善本体感觉。我们的目标是确定随机共振刺激与护膝相结合是否会降低膝关节骨关节炎患者步态中的冲动负荷率和肌肉共同收缩。
在三种不同条件下，对膝关节骨关节炎患者行走时的步态动力学、运动学和肌肉活动进行评估：无随机共振/无护膝（对照）、75%阈值下的随机共振/护膝，以及无随机共振/护膝。根据地面反作用力计算负荷率。根据股外侧肌与股二头肌外侧活动的比率计算肌肉共同收缩。使用重复测量方差分析评估不同条件之间的差异（P<0.05）。
与对照条件相比，75%阈值/护膝和仅护膝条件导致接触时膝关节屈曲增加，负荷率降低（P<0.05）。然而，在75%阈值/护膝和仅护膝条件之间，这些测量结果没有显著差异。与其他条件相比，发现75%阈值/护膝条件下肌肉共同收缩减少。
膝关节屈曲增加和负荷率降低可能是护膝或护膝/刺激组合导致本体感觉改善的结果。除了肌肉共同收缩减少外，随机共振刺激未显示出增强护膝效果的能力。
