Lanza Marcel B, Baghi Raziyeh, Frakes Nathan, Lateef Shabnam, Martins Líbyna Thaynara Calandrelli, Zhang Li-Qun, Gray Vicki L
Department of Physical Therapy and Rehabilitation Science, University of Maryland School of Medicine, Baltimore, MD, USA.
Department of Physical Therapy and Rehabilitation Science, University of Maryland, Baltimore, 100 Penn Street, Baltimore, MD, 20201, USA.
Sci Rep. 2025 Mar 18;15(1):9247. doi: 10.1038/s41598-025-94158-z.
The primary aim of this study was to investigate how measurements from different regions along the rectus femoris (RF) and vastus lateralis (VL) influence muscle morphology, including muscle thickness (MT), muscle stiffness, and muscle quality. An exploratory aim was to examine whether an association exists between voluntary and involuntary force and muscle morphology across the same regions. In one session, participants (n = 13) underwent ultrasound imaging (US), followed by knee extension maximal isometric voluntary contractions and evoked contractions. US recordings (at rest) and testing were conducted while participants were seated at 90º knee flexion (dominant leg) on an isokinetic dynamometer. Muscle morphology was recorded at proximal, medial, and distal regions of RF and VL. During maximum contractions, participants were instructed to exert maximal effort as fast and as forcefully as possible for 5 s, while evoked contractions were performed via femoral nerve stimulation. A one-way repeated measures ANOVA was used for the main aim, while Spearman bivariate correlations were used for the exploratory aim. The primary findings showed that the RF and VL muscles were significantly larger in the medial region (P ≤ 0.023), with no significant differences in muscle quality or stiffness within the same muscle. Additionally, a significant overall relationship was observed between muscle quality and the rate of force development in both muscles (P ≤ 0.037). In conclusion, muscle size varies across the length of the VL and RF muscles, with no changes in muscle quality or stiffness. Furthermore, muscle quality demonstrates a significant association with rate of force development.
本研究的主要目的是调查沿股直肌（RF）和股外侧肌（VL）不同区域的测量如何影响肌肉形态，包括肌肉厚度（MT）、肌肉僵硬度和肌肉质量。一个探索性目的是检验同一区域的随意力和非随意力与肌肉形态之间是否存在关联。在一次实验中，参与者（n = 13）接受超声成像（US），随后进行膝关节伸展最大等长随意收缩和诱发收缩。在参与者坐在等速测力计上，膝关节屈曲90°（优势腿）时进行US记录（静息时）和测试。在RF和VL的近端、内侧和远端区域记录肌肉形态。在最大收缩期间，指示参与者在5秒内尽可能快速、有力地施加最大努力，而诱发收缩通过股神经刺激进行。主要目的采用单因素重复测量方差分析，探索性目的采用Spearman双变量相关性分析。主要研究结果表明，RF和VL肌肉在内侧区域明显更大（P≤0.023），同一肌肉内的肌肉质量或僵硬度无显著差异。此外，观察到两块肌肉的肌肉质量与力量发展速率之间存在显著的总体关系（P≤0.037）。总之，VL和RF肌肉的大小在其长度上有所变化，肌肉质量或僵硬度没有变化。此外，肌肉质量与力量发展速率之间存在显著关联。
