Rutherford Derek James, Hubley-Kozey Cheryl, Stanish William
School of Physiotherapy, Dalhousie University, 4th Floor Forrest Building, 5869 University Avenue, Halifax, NS, Canada, B3H 3J5.
Department of Surgery, Division of Orthopaedics, Dalhousie University, Halifax, NS, Canada.
Clin Biomech (Bristol). 2014 May;29(5):545-50. doi: 10.1016/j.clinbiomech.2014.03.009. Epub 2014 Mar 26.
Hip abductor muscles generate moments of force that control lower extremity frontal plane motion. Strengthening these muscles has been a recent trend in therapeutic intervention studies for knee osteoarthritis. The current study investigated the relationship between hip abductor muscle function (strength and activation) and the net external knee adduction moment during gait in those with medial compartment knee osteoarthritis.
54 individuals with moderate knee osteoarthritis walked at their self-selected velocity while gluteus medius electromyograms, segment motions and ground reaction forces were recorded. Net external knee adduction moment (KAM) and linear enveloped electromyographic profiles were calculated. Peak KAM was determined and then principal component analyses (PCA) were applied to KAM and electromyographic profiles. Isometric hip abductor strength, anthropometrics and gait velocity were measured. Multiple regression models evaluated the relationship between walking velocity, hip abductor strength, electromyographic variables recorded during gait and KAM waveform characteristics.
Minimal peak KAM variance was explained by abductor strength (R(2)=9%, P=0.027). PCA-based KAM waveform characteristics were not explained by abductor strength. Overall gluteus medius amplitude (PP1-scores) was related to a reduction in the bi-modal KAM (PP3-scores) pattern (R(2)=16%, P=0.003).
There was no clear relationship between hip abductor muscle strength and specific amplitude and temporal KAM characteristics. Higher overall gluteus medius activation amplitude was related to a sustained KAM during mid-stance. 84 to 90% of the variance in KAM waveform characteristics was not explained by hip abductor muscle function showing hip abductor muscle function has minimal association to KAM characteristics.
髋外展肌产生控制下肢额状面运动的力矩。加强这些肌肉已成为膝关节骨关节炎治疗干预研究中的一种新趋势。本研究调查了内侧间室膝关节骨关节炎患者在步态过程中髋外展肌功能（力量和激活）与膝关节净内收力矩之间的关系。
54名中度膝关节骨关节炎患者以自我选择的速度行走，同时记录臀中肌肌电图、节段运动和地面反作用力。计算膝关节净内收力矩（KAM）和线性包络肌电图曲线。确定KAM峰值，然后对KAM和肌电图曲线进行主成分分析（PCA）。测量等长髋外展肌力量、人体测量学指标和步态速度。多元回归模型评估步行速度、髋外展肌力量、步态期间记录的肌电图变量与KAM波形特征之间的关系。
外展肌力量解释的KAM峰值方差最小（R² = 9%，P = 0.027）。基于PCA的KAM波形特征无法由外展肌力量解释。臀中肌总体振幅（PP1评分）与双峰KAM（PP3评分）模式的减少有关（R² = 16%，P = 0.003）。
髋外展肌力量与特定的振幅和KAM时间特征之间没有明确关系。臀中肌较高的总体激活振幅与站立中期持续的KAM有关。KAM波形特征中84%至90%的方差无法由髋外展肌功能解释，表明髋外展肌功能与KAM特征的关联最小。
