Department of Physical Therapy and Rehabilitation, School of Medicine, University of Maryland, Baltimore, MD, USA.
Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, Brazil -
J Sports Med Phys Fitness. 2023 Nov;63(11):1194-1201. doi: 10.23736/S0022-4707.23.15090-0. Epub 2023 Sep 7.
Magnetic resonance imaging (MRI) is a well-used technique to assess muscle size and can be acquired on different planes. Pectoralis major (PM) and triceps brachii (TB) muscles are often acquired and analyzed on the axial plane, however it is unknown if anatomical cross-sectional area (CSA) calculated from different planes will affect the muscle size-strength relationship. Thus, the first aim of the present study was to identify if the CSA of the PM and TB measured on different planes presents a similar muscle size-strength relationship. A secondary aim was to investigate if the quantification of CSA of the PM and TB muscles are similar between sagittal and axial plane.
Fifteen males underwent an MRI examination, and after that, one-repetition maximum (1RM) test was performed.
There was a significant relationship between 1RM and PM CSA measured on the axial and sagittal plane (r≤0.81), while the relationship with TB CSA was only good on the axial plane (r=0.65) and not significant on the sagittal plane (r=0.27). ICC between planes was excellent for PM CSA (0.96) with Bland-Altman procedure showing agreement between planes (d=0.376; P=0.612). Contrarily, TB CSA ICC was week (0.07), with Bland-Altman procedure showing no agreement between planes (d=-24.49; P=0.022).
CSA measured at axial plane from PM and TB muscles showed a significant relationship with 1RM, while only PM CSA on the sagittal plane showed a significant relationship with 1RM. Finally, it was demonstrated that PM images showed a great reliability between planes, which was not true for TB muscle.
磁共振成像（MRI）是一种常用于评估肌肉大小的技术，可在不同平面上采集。胸大肌（PM）和肱三头肌（TB）肌肉通常在轴位上采集和分析，但尚不清楚从不同平面计算的解剖横截面积（CSA）是否会影响肌肉大小-力量关系。因此，本研究的首要目的是确定 PM 和 TB 肌肉在不同平面上测量的 CSA 是否具有相似的肌肉大小-力量关系。次要目的是研究 PM 和 TB 肌肉 CSA 的定量在矢状面和轴位之间是否相似。
15 名男性接受了 MRI 检查，之后进行了一次重复最大（1RM）测试。
PM 肌肉在轴位和矢状位上测量的 CSA 与 1RM 呈显著相关（r≤0.81），而与 TB CSA 的相关性仅在轴位上良好（r=0.65），在矢状位上不显著（r=0.27）。PM CSA 之间的 ICC 非常好（0.96），Bland-Altman 程序显示平面之间的一致性（d=0.376；P=0.612）。相反，TB CSA 的 ICC 较差（0.07），Bland-Altman 程序显示平面之间无一致性（d=-24.49；P=0.022）。
PM 和 TB 肌肉在轴位上测量的 CSA 与 1RM 呈显著相关，而只有 PM 在矢状位上的 CSA 与 1RM 呈显著相关。最后，结果表明 PM 图像在平面之间具有很好的可靠性，而 TB 肌肉则不然。
