Al Amer Hamad S, Sabbahi Mohamed A, Alrowayeh Hesham N, Bryan William J, Olson Sharon L
Department of Health Rehabilitation Sciences, Faculty of Applied Medical Sciences, University of Tabuk, Tabuk 71491, Saudi Arabia.
School of Physical Therapy, Texas Woman's University, 6700 Fannin Street, Houston, TX 77030, USA.
Healthcare (Basel). 2025 Apr 17;13(8):920. doi: 10.3390/healthcare13080920.
: Knee osteoarthritis (OA) impairs functional mobility, including sit-to-stand and stand-to-sit movements. Thigh muscles stabilize the knee during these transitions, and variations in seat height and foot positioning may affect muscle activation. Assessing thigh muscle activity during these tasks may provide strategies to enhance function and guide targeted rehabilitation for individuals with knee OA. : The aim of this study was to examine the EMG activity of the vastus medialis oblique (VMO), rectus femoris (RF), and biceps femoris (BF) muscles of arthritic knees during sit-to-stand and stand-to-sit movements when using varying seat heights and feet positions. : The EMG activity was recorded from the three thigh muscles in the arthritic side during sit-to-stand and stand-to-sit movements under six different seating conditions from eight patients (three females; mean age: 64.6 ± 11.0 years). A three-way ANOVA was used to examine the effects of seat height, foot positioning, and movement type on muscle activation. : The results demonstrated significant interactions between muscle activation, movement type, and seating conditions ( = 0.022). The EMG activity of VMO and RF increased significantly during sit-to-stand movements from lower seat heights compared to knee-height seats ( < 0.05). RF activation was also significantly elevated during stand-to-sit transitions at low seat heights ( = 0.023). Additionally, sit-to-stand transitions with symmetrical foot placement elicited significantly greater VMO activation compared to BF activation ( < 0.05). While BF activation remained relatively low across most conditions, it was highest when the arthritic knee was positioned behind the sound foot during both movements. : Seat height and foot positioning significantly impact thigh muscle activation in individuals with knee OA during sit-to-stand and stand-to-sit transitions. Lower seat heights require greater VMO and RF activation, indicating increased mechanical demands. Additionally, placing the arthritic knee behind the sound foot enhances BF activation, suggesting a potential strategy for targeted hamstring engagement. These findings provide directions for quadriceps and hamstring strengthening, alongside strategic seating adjustments to optimize functional mobility and reduce joint stress in individuals with knee OA.
膝关节骨关节炎（OA）会损害功能活动能力，包括从坐姿到站立以及从站立到坐姿的动作。在这些动作转换过程中，大腿肌肉起到稳定膝关节的作用，而座椅高度和脚部位置的变化可能会影响肌肉激活。评估这些任务期间的大腿肌肉活动，可能会为改善功能提供策略，并为膝关节OA患者指导有针对性的康复治疗。
本研究的目的是，在使用不同座椅高度和脚部位置时，检查关节炎膝关节在从坐姿到站立以及从站立到坐姿动作过程中，股内侧斜肌（VMO）、股直肌（RF）和股二头肌（BF）的肌电图（EMG）活动。
在8名患者（3名女性；平均年龄：64.6±11.0岁）的六种不同就座条件下，记录了关节炎一侧的三块大腿肌肉在从坐姿到站立以及从站立到坐姿动作过程中的EMG活动。使用三因素方差分析来检查座椅高度、脚部位置和动作类型对肌肉激活的影响。
结果表明，肌肉激活、动作类型和就座条件之间存在显著的交互作用（P = 0.022）。与膝盖高度的座椅相比，从较低座椅高度进行从坐姿到站立动作时，VMO和RF的EMG活动显著增加（P < 0.05）。在低座椅高度从站立到坐姿转换过程中，RF的激活也显著升高（P = 0.023）。此外，与BF激活相比，双脚对称放置进行从坐姿到站立转换时，VMO激活显著更大（P < 0.05）。虽然在大多数情况下BF激活相对较低，但在两个动作过程中，当关节炎膝关节位于健侧脚后方时，BF激活最高。
座椅高度和脚部位置在膝关节OA患者从坐姿到站立以及从站立到坐姿转换过程中，对大腿肌肉激活有显著影响。较低的座椅高度需要更大的VMO和RF激活，表明机械需求增加。此外，将关节炎膝关节置于健侧脚后方可增强BF激活，提示一种有针对性的腘绳肌参与策略。这些发现为股四头肌和腘绳肌强化提供了指导方向，同时也为策略性就座调整提供了方向，以优化功能活动能力并减轻膝关节OA患者的关节压力。
