Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Thessaloniki, Greece.
J Electromyogr Kinesiol. 2011 Oct;21(5):689-94. doi: 10.1016/j.jelekin.2011.05.006.
The purpose of this study was to investigate the neuromuscular efficiency of women with knee osteoarthritis (OA) when performing a sit-to-stand movement and during maximum strength efforts. Twelve women with unilateral knee OA (age 60.33±6.66 years, height 1.61±0.05 m, mass 77.08±9.2 kg) and 11 controls (age 56.54±5.46 years, height 1.64±0.05 m, mass 77.36±13.34 kg) participated in this study. Subjects performed a sit-to-stand movement from a chair while position of center of pressure and knee angular speed were recorded. Furthermore, maximal isokinetic knee extension and flexion strength at 60°/s, 120°/s and 150°/s was measured. Surface, electromyography (EMG) from the biceps femoris (BF), vastus lateralis (VL) and vastus medialis (VM) was recorded during all tests. Analysis of variance (ANOVA) showed that during the sit-to-stand OA group demonstrated significantly lower knee angular speed (44.49±9.61°/s vs. 71.68±19.86°/s), a more posterior position of the center of pressure (39.20±7.02% vs. 41.95±2.49%) and a higher antagonist BF activation (57.13±20.55% vs. 32.01±19.5%) compared with controls (p<0.05). Further, women with knee OA demonstrated a lower Moment-to-EMG ratio than controls in extension and eccentric flexion at 60°/s and 150°/s, while the opposite was found for concentric flexion at 60°/s (p<0.05). Among other factors, the slower performance of the sit-to-stand movement in women with OA is due to a less efficient use of the knee extensor muscles (less force per unit of EMG) and, perhaps, a higher BF antagonist co-activation. This may lead subjects with OA to adopt a different movement strategy compared with controls.
本研究旨在探讨膝骨关节炎（OA）女性在进行坐站运动和最大力量努力时的神经肌肉效率。12 名单侧膝 OA 女性（年龄 60.33±6.66 岁，身高 1.61±0.05m，体重 77.08±9.2kg）和 11 名对照组（年龄 56.54±5.46 岁，身高 1.64±0.05m，体重 77.36±13.34kg）参与了这项研究。受试者从椅子上进行坐站运动，同时记录中心压力位置和膝关节角速度。此外，还测量了 60°/s、120°/s 和 150°/s 时最大等速膝关节伸展和屈曲力量。在所有测试中，记录了股二头肌（BF）、股外侧肌（VL）和股内侧肌（VM）的表面肌电图（EMG）。方差分析（ANOVA）显示，在坐站期间，OA 组的膝关节角速度明显较低（44.49±9.61°/s 对 71.68±19.86°/s），中心压力位置更靠后（39.20±7.02%对 41.95±2.49%），拮抗剂 BF 的激活更高（57.13±20.55%对 32.01±19.5%）与对照组相比（p<0.05）。此外，与对照组相比，膝骨关节炎女性在 60°/s 和 150°/s 时的伸展和离心屈曲的力矩与 EMG 比值较低，而在 60°/s 时的向心屈曲则相反（p<0.05）。在其他因素中，OA 女性坐站运动的表现较慢是由于膝关节伸肌的利用效率较低（单位 EMG 的力较小），并且，BF 拮抗剂的协同激活可能较高。这可能导致 OA 患者与对照组相比采用不同的运动策略。
