Trevino Michael, Perez Sergio, Sontag Stephanie, Olmos Alex, Jeon Sunggun, Richardson Lyric
Applied Neuromuscular Physiology Laboratory, Department of Kinesiology, Applied Health, and Recreation, Oklahoma State University, Stillwater, OK 74078, USA.
J Funct Morphol Kinesiol. 2023 May 2;8(2):53. doi: 10.3390/jfmk8020053.
This study examined potential sex-related differences and correlations among the pennation angle (PA), muscle thickness (MT), and mechanomyographic amplitude (MMG)-torque relationships of the vastus lateralis (VL) in 11 healthy males and 12 healthy females. The PA and MT of the VL were quantified with ultrasound. Participants performed an isometric muscle action of the knee extensors that linearly increased to 70% of maximal strength followed by a 12 s plateau. MMG was recorded from the VL. Linear regression models were fit to the log-transformed MMG-torque relationships to calculate terms (slopes) for the linearly increasing segment. MMG was averaged during the plateau. Males exhibited greater PA ( < 0.001), MT ( = 0.027), terms ( = 0.005), and MMG ( = 0.016). The terms were strongly ( < 0.001, = 0.772) and moderately correlated ( = 0.004, = 0.571) with PA and MT, respectively, while MMG was moderately correlated with PA ( = 0.018, = 0.500) and MT ( = 0.014, = 0.515). The greater mechanical behavior of individuals possessing a larger PA and MT of the VL may reflect increased cross-bridge activity within the muscle fibers. Additionally, PA may help explain sex-related differences in MMG between sexes.
本研究调查了11名健康男性和12名健康女性股外侧肌（VL）的羽状角（PA）、肌肉厚度（MT）以及肌机械图幅度（MMG）与扭矩关系之间潜在的性别差异和相关性。通过超声对VL的PA和MT进行量化。参与者进行膝关节伸肌的等长肌肉动作，力量线性增加至最大力量的70%，随后保持12秒的平稳状态。从VL记录MMG。对经对数转换的MMG-扭矩关系拟合线性回归模型，以计算线性增加段的系数（斜率）。在平稳期对MMG进行平均。男性表现出更大的PA（P<0.001）、MT（P = 0.027）、系数（P = 0.005）和MMG（P = 0.016）。系数分别与PA和MT呈强相关（P<0.001，r = 0.772）和中度相关（P = 0.004，r = 0.571），而MMG与PA（P = 0.018，r = 0.500）和MT（P = 0.014，r = 0.515）呈中度相关。VL的PA和MT较大的个体具有更大的力学行为，这可能反映了肌纤维内横桥活性的增加。此外，PA可能有助于解释两性之间MMG的性别差异。
