School of Kinesiology and Health Science, York University, Toronto, ON, Canada; School of Rehabilitation Science, McMaster University, Hamilton, ON, Canada.
Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada.
Clin Biomech (Bristol). 2020 Dec;80:105165. doi: 10.1016/j.clinbiomech.2020.105165. Epub 2020 Aug 29.
Infiltration of muscle with non-lean tissue, such as fat, reduces muscle quality. Ultrasound captures muscle quality through measurement of echogenicity. Given the potential implications of quadriceps muscle quality on physical function, particularly in knee osteoarthritis, the purpose of this study was to investigate the relationship between echogenicity, muscle thickness and subcutaneous fat thickness with the clinical severity of osteoarthritis.
Thirty-one women with clinical knee osteoarthritis participated. Rectus femoris and vastus lateralis echogenicity, muscle thickness and subcutaneous fat thickness were measured from ultrasound images of the most symptomatic knee. Clinical severity of osteoarthritis was characterized with pain, self-reported function, six-minute walk test, and knee extensor strength. Correlation coefficients were calculated between muscle and fat architecture outcomes (muscle quality, muscle and fat thicknesses) and osteoarthritis clinical severity outcomes.
Data from 25 women were of sufficient quality for analysis. Echogenicity (muscle quality) related to the six-minute walk test for both rectus femoris (r = -0.52, p = 0.02) and vastus lateralis (r = -0.74, p = 0.004), with poorer muscle quality related to lower mobility. Subcutaneous fat thickness was related to the six-minute walk test (rectus femoris, r = -0.61, p = 0.0012; vastus lateralis, r = -0.73, p = 0.003) and strength (rectus femoris, r = -0.46, p = 0.02; vastus lateralis, r = -0.59, p = 0.03). Muscle thickness was not related to any severity outcomes.
Muscle quality, rather than thickness, is associated with mobility performance in women with knee osteoarthritis. Thus, interventions for osteoarthritis that specifically target muscle quality, rather than size, should be explored.
肌肉中浸润非肌肉组织，如脂肪，会降低肌肉质量。超声通过测量回声来捕捉肌肉质量。鉴于股四头肌质量对身体功能的潜在影响，特别是在膝骨关节炎中，本研究旨在探讨回声、肌肉厚度和皮下脂肪厚度与骨关节炎临床严重程度的关系。
31 名患有临床膝骨关节炎的女性参与了研究。从最症状性膝关节的超声图像中测量股直肌和股外侧肌的回声、肌肉厚度和皮下脂肪厚度。骨关节炎的临床严重程度通过疼痛、自我报告的功能、六分钟步行试验和膝关节伸肌力量来描述。计算肌肉和脂肪结构结果（肌肉质量、肌肉和脂肪厚度）与骨关节炎临床严重程度结果之间的相关系数。
25 名女性的数据质量足以进行分析。股直肌和股外侧肌的回声（肌肉质量）与六分钟步行试验相关（股直肌，r=-0.52，p=0.02；股外侧肌，r=-0.74，p=0.004），肌肉质量越差，移动能力越差。皮下脂肪厚度与六分钟步行试验（股直肌，r=-0.61，p=0.0012；股外侧肌，r=-0.73，p=0.003）和力量（股直肌，r=-0.46，p=0.02；股外侧肌，r=-0.59，p=0.03）相关。肌肉厚度与任何严重程度结果均无关。
在患有膝骨关节炎的女性中，肌肉质量而不是厚度与运动表现相关。因此，应该探索专门针对肌肉质量而不是大小的骨关节炎干预措施。
