Department of Physical Education, Graduate School of Education, Yong In University, Yongin-si, Gyeongki-do, Republic of Korea.
Department of Orthopaedic Surgery, Kyung Hee University Hospital, Seoul, Republic of Korea.
Medicine (Baltimore). 2022 Oct 21;101(42):e31104. doi: 10.1097/MD.0000000000031104.
Weakening muscle strength around the knee tends to render it vulnerable to aging-related damage. This study aimed to examine the association between knee flexor muscle strength and its cross-sectional area (CSA). We also evaluated aging-related changes in flexor muscle strength and CSA. We retrospectively analyzed 252 patients with acute-onset knee pain (<1 month) between September 2006 and August 2009 in accordance with the Strengthening the Reporting of Observational studies in Epidemiology statement. The CSA of each knee flexor muscle (biceps femoris, sartorius, gracilis, semitendinosus (ST), and semimembranosus (SM)) was measured on magnetic resonance imaging axial images at the suprapatellar level. We evaluated flexor muscle strength (peak torque in N.m) using a Cybex dynamometer at 60°/second and 180°/second and its correlation with CSA. In total, 252 patients (mean age, 34.5 years; range, 11 to 66 years; 184 men and 68 women) were included in this study. No significant intergroup differences in demographic data such as sex or body mass index were found. Mean CSA was 605.4 mm2 for the SM, 444.7 mm2 for the biceps femoris, 282 mm2 for the sartorius, 55.4 mm2 for the ST, and 34.1 mm2 for the gracilis. Mean peak torques were 67.4 N.m and 52.7 N.m at 60°/second and 180°/second, respectively. CSA was positively correlated with flexion strengths of 60°/second (R = 0.363, P < .001) and 180°/second (R = 0.354, P < .001). Muscle strength was associated with CSA in all muscles but the gracilis (R = 0.056, P = .375). Flexion strength decreased significantly with aging from the thirties. Total CSA decreased with aging (r = -0.247, P < .001). The CSA of the biceps femoris, sartorius, SM, and ST decreased significantly, whereas that of the gracilis tended to decrease non-significantly with aging. Flexor muscle strength was associated with total muscle CSA on magnetic resonance imaging and the CSA of every muscle except the gracilis. Flexion strength decreased significantly with aging after the twenties, while total CSA decreased significantly with aging. The CSA of all flexor muscles decreased significantly with aging, whereas that of the gracilis decreased only slightly.
膝关节周围肌肉力量减弱容易导致与衰老相关的损伤。本研究旨在探讨膝关节屈肌力量与其横截面积（CSA）之间的关系。我们还评估了屈肌力量和 CSA 的与年龄相关的变化。我们根据《加强观察性研究的报告：流行病学规范》（Strengthening the Reporting of Observational studies in Epidemiology）的声明，回顾性分析了 2006 年 9 月至 2009 年 8 月期间 252 例急性膝关节疼痛（<1 个月）患者的资料。在髌上水平的磁共振成像轴位图像上测量每个膝关节屈肌（股二头肌、缝匠肌、股薄肌、半腱肌（ST）和半膜肌（SM））的 CSA。我们使用 Cybex 测力计以 60°/秒和 180°/秒评估屈肌力量（N.m 的峰值扭矩），并评估其与 CSA 的相关性。共有 252 例患者（平均年龄 34.5 岁；范围 11 至 66 岁；184 名男性和 68 名女性）纳入本研究。性别或体重指数等人口统计学数据在组间无显著差异。SM 的平均 CSA 为 605.4 mm2，股二头肌为 444.7 mm2，缝匠肌为 282 mm2，ST 为 55.4 mm2，股薄肌为 34.1 mm2。60°/秒和 180°/秒时的平均峰值扭矩分别为 67.4 N.m 和 52.7 N.m。CSA 与 60°/秒（R = 0.363，P <.001）和 180°/秒（R = 0.354，P <.001）的屈伸强度呈正相关。肌肉力量与除股薄肌以外的所有肌肉的 CSA 相关（R = 0.056，P =.375）。从三十多岁开始，屈伸强度随年龄显著下降。总 CSA 随年龄增长而下降（r = -0.247，P <.001）。股二头肌、缝匠肌、SM 和 ST 的 CSA 显著下降，而股薄肌的 CSA 则略有下降。屈肌力量与磁共振成像上的总肌肉 CSA 以及除股薄肌以外的每块肌肉的 CSA 相关。二十多岁以后，屈伸强度随年龄显著下降，而总 CSA 随年龄显著下降。所有屈肌肌肉的 CSA 随年龄显著下降，而股薄肌仅略有下降。
