Nakao Gakuto, Kodesho Taiki, Yamagata Kazuma, Watanabe Kota, Ohsaki Yuki, Katayose Masaki, Taniguchi Keigo
Graduate School of Health Sciences, Sapporo Medical University, Sapporo, JPN.
Department of Physical Therapy, Sapporo Medical Technology, Welfare and Dentistry Professional Training College of Nishino Gakuen School Foundation, Sapporo, JPN.
Cureus. 2024 Aug 31;16(8):e68343. doi: 10.7759/cureus.68343. eCollection 2024 Aug.
This study used ultrasound shear wave elastography (SWE) to evaluate the mechanical properties of hamstring muscles from cadaveric specimens with knee flexion contractures.
Hamstring muscles for tensile testing were harvested from Thiel soft-embalmed cadavers with and without knee flexion contracture. Muscle specimens were mounted on a testing machine. The initial load detected when a tensile load was applied to the distal end was used as the slack length. The cross-sectional areas of the muscle at slack length were measured at the proximal and distal sites using B-mode ultrasonography. Subsequently, the muscle specimen was elongated from the slack length to 8% strain, with the shear modulus measured using SWE. Young's modulus (stress/strain) was calculated based on the displacement and tensile force obtained from the tensile test.
Regression analysis showed a significant positive linear relationship between the Young's and shear moduli for all specimens at all the sites (P < 0.01 and coefficient of determination: 0.95-0.99). The Young's and average shear moduli at the proximal and distal sites were higher in all hamstring muscles with contractures than in those without contractures.
SWE can be used to estimate Young's moduli of hamstring muscles with contractures. Muscle specimens with contractures exhibited higher resistance to elongation, thereby indicating that their mechanical properties differed from those of muscles without contractures.
本研究采用超声剪切波弹性成像（SWE）评估膝关节屈曲挛缩尸体标本中绳肌的力学性能。
从经蒂尔氏液软防腐处理的尸体上获取用于拉伸试验的绳肌，这些尸体有无膝关节屈曲挛缩。将肌肉标本安装在试验机上。当向远端施加拉伸载荷时检测到的初始载荷用作松弛长度。使用B型超声在近端和远端测量松弛长度时肌肉的横截面积。随后，将肌肉标本从松弛长度拉长至8%应变，同时使用SWE测量剪切模量。根据拉伸试验获得的位移和拉力计算杨氏模量（应力/应变）。
回归分析表明，所有部位所有标本的杨氏模量和剪切模量之间均存在显著的正线性关系（P < 0.01，决定系数：0.95 - 0.99）。所有有挛缩的绳肌近端和远端的杨氏模量和平均剪切模量均高于无挛缩的绳肌。
SWE可用于估计有挛缩的绳肌的杨氏模量。有挛缩的肌肉标本表现出更高的抗伸长能力，从而表明其力学性能与无挛缩的肌肉不同。
