Luo Xinran, Wang Qiaojie, Tan Hongyu, Zhao Wenbo, Yao Yifei, Lu Shengdi
School of Biomedical Engineering, Shanghai Tech University, Shanghai, China.
Department of Joint Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Digit Health. 2025 Jan 3;11:20552076241311940. doi: 10.1177/20552076241311940. eCollection 2025 Jan-Dec.
Obesity and severe knee osteoarthritis (KOA) lead to significant gait and muscle adaptations. However, the relationship between core muscle strength and the severity of KOA in obese patients remains unclear. This study aimed to determine the association between muscle strength adaptation and the severity of KOA in obese individuals.
We recruited 119 obese participants with unilateral KOA from January 2021 to December 2023, all classified with mild to moderate KOA grades. KOA severity was assessed using the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), which categorized participants into two groups based on disease severity. Electromyographic data from the psoas, gluteus medius, vastus lateralis, vastus medialis, rectus femoris, medial gastrocnemius, lateral gastrocnemius, tibialis anterior, and biceps femoris muscles were collected during isometric and dynamic knee extension.
Significant differences were observed in all selected muscles between the affected knee joint and the contralateral side during both dynamic and isometric knee extensions. The difference in electromyographic data-including mean absolute value (MAV), root mean square (RMS), and center frequency (CF)-was significantly different across groups categorized by KOA severity. Notably, the MAV values of the vastus medialis, lateral gastrocnemius, and biceps femoris, as well as the CF values of the medial and lateral gastrocnemius, showed no significant differences in some instances during both dynamic and isometric extensions.
This study indicates that obese individuals with KOA exhibit lower muscle intensity and higher fatigability in comparison to the contralateral side during both isometric and dynamic knee extensions. Furthermore, significant reductions in muscle intensity were observed in the psoas, gluteus medius, vastus lateralis, rectus femoris, medial gastrocnemius, and tibialis anterior muscles, correlating with the advanced severity of KOA.
肥胖和重度膝骨关节炎（KOA）会导致显著的步态和肌肉适应性变化。然而，肥胖患者的核心肌肉力量与KOA严重程度之间的关系仍不明确。本研究旨在确定肥胖个体中肌肉力量适应性与KOA严重程度之间的关联。
我们在2021年1月至2023年12月期间招募了119名单侧KOA的肥胖参与者，所有参与者均被分类为轻度至中度KOA等级。使用西安大略和麦克马斯特大学骨关节炎指数（WOMAC）评估KOA严重程度，该指数根据疾病严重程度将参与者分为两组。在等长和动态膝关节伸展过程中，收集腰大肌、臀中肌、股外侧肌、股内侧肌、股直肌、腓肠肌内侧头、腓肠肌外侧头、胫骨前肌和股二头肌的肌电图数据。
在动态和等长膝关节伸展过程中，患侧膝关节与对侧相比，所有选定肌肉均观察到显著差异。根据KOA严重程度分类的各组之间，肌电图数据的差异，包括平均绝对值（MAV）、均方根（RMS）和中心频率（CF），有显著差异。值得注意的是，在动态和等长伸展过程中的某些情况下，股内侧肌、腓肠肌外侧头和股二头肌的MAV值，以及腓肠肌内侧头和外侧头的CF值，没有显著差异。
本研究表明，与对侧相比，KOA肥胖个体在等长和动态膝关节伸展过程中表现出更低的肌肉强度和更高的疲劳性。此外，在腰大肌、臀中肌、股外侧肌、股直肌、腓肠肌内侧头和胫骨前肌中观察到肌肉强度显著降低，这与KOA的严重程度增加相关。
