Cruz-Montecinos Carlos, Pinto Matheus D, Pinto Ronei S
Department of Physical Therapy, Faculty of Medicine, University of Chile, Santiago, Chile.
Research, Innovation, and Development Section in Kinesiology, Kinesiology Unit, San José Hospital, Santiago, Chile.
J Anat. 2025 Jan;246(1):98-107. doi: 10.1111/joa.14136. Epub 2024 Sep 26.
The distribution and amount of intramuscular fat and fibrous tissue can be influenced by biological sex and impact muscle quality in both the functional (force-generating capacity) and morphological (muscle composition) domains. While ultrasonography (US) has proven effective in assessing age- or sex-related differences in muscle quality, limited information is available on sex differences in children. Quantitative ultrasonographic measurements, such as echo intensity (EI), EI bands (number of pixels across 50-unit intervals) and texture, may offer a comprehensive framework for identifying sex differences in muscle composition. The aim of our study was to examine the effect of sex on the rectus femoris (RF) muscle quality in children. We used EI (mean and bands) and texture as muscle quality estimates derived from B-mode US. We hypothesised that RF muscle quality differs significantly between girls and boys. Additionally, we also hypothesised that there is a significant correlation between EI bands and texture. Forty-four non-active healthy children were recruited (n = 22 girls, 12.8 ± 1.5 years; and n = 22 boys, 13.5 ± 1.2 years). RF was assessed using EI mean, EI bands, and texture analysis (homogeneity and correlation) using the Gray-Level Co-Occurrence Matrix. The results revealed significant (p < 0.05) sex differences in RF EI bands and texture. Boys displayed higher values in the 0-50 EI band and had more homogeneous muscle texture than girls. Conversely, girls displayed greater values in the 51-100 EI band and had less homogenous texture compared to boys (p < 0.05). A positive correlation was observed between the 0-50 EI band and muscle homogeneity. However, the 51-100 EI band correlated negatively with homogeneity (p < 0.05), particularly for girls. In conclusion, our study revealed sex-specific differences in mean EI, EI bands, and texture of the RF muscle in children. The variations in the correlations between the first and second EI bands and texture reveal different levels of homogeneity in each band. This indicates that distinct muscle tissue constituents, such as intramuscular fat and/or connective tissue, may be reflected in EI bands. Overall, the methods used in this study may be useful for examining muscle quality in healthy children and those with medical conditions.
肌肉内脂肪和纤维组织的分布及数量会受到生物性别的影响，并在功能（力量产生能力）和形态（肌肉组成）方面对肌肉质量产生影响。虽然超声检查（US）已被证明在评估与年龄或性别相关的肌肉质量差异方面有效，但关于儿童性别差异的信息有限。定量超声测量，如回声强度（EI）、EI带（50单位间隔内的像素数）和纹理，可能为识别肌肉组成中的性别差异提供一个全面的框架。我们研究的目的是探讨性别对儿童股直肌（RF）肌肉质量的影响。我们使用EI（平均值和带）和纹理作为从B模式超声获得的肌肉质量估计值。我们假设女孩和男孩的RF肌肉质量存在显著差异。此外，我们还假设EI带与纹理之间存在显著相关性。招募了44名不活跃的健康儿童（n = 22名女孩，年龄12.8±1.5岁；n = 22名男孩，年龄13.5±1.2岁）。使用EI平均值、EI带以及使用灰度共生矩阵进行纹理分析（均匀性和相关性）来评估RF。结果显示RF的EI带和纹理存在显著（p < 0.05）的性别差异。男孩在0 - 50 EI带的值较高，且肌肉纹理比女孩更均匀。相反，女孩在51 - 100 EI带的值更大，与男孩相比纹理均匀性更低（p < 0.05）。在0 - 50 EI带与肌肉均匀性之间观察到正相关。然而，51 - 100 EI带与均匀性呈负相关（p < 0.05），尤其是对于女孩。总之，我们的研究揭示了儿童RF肌肉在平均EI、EI带和纹理方面的性别特异性差异。第一和第二EI带与纹理之间相关性的变化揭示了每个带中不同程度的均匀性。这表明不同的肌肉组织成分，如肌肉内脂肪和/或结缔组织，可能在EI带中得到反映。总体而言，本研究中使用的方法可能有助于检查健康儿童和患有疾病儿童的肌肉质量。
