Aponeuroses are stiff sheath-like components of the muscle-tendon unit that play a vital role in force transmission and thus locomotion. There is clear importance of the aponeurosis in musculoskeletal function, but there have been relatively few studies of aponeurosis material properties to date. The goals of this work were to: 1) perform tensile stress-relaxation tests, 2) perform planar biaxial tests, 3) employ computational modeling to the data from 1 to 2, and 4) perform scanning electron microscopy to determine collagen fibril organization for aponeurosis tissue. Viscoelastic modeling and statistical analysis of stress-relaxation data showed that while relaxation rate differed statistically between strain levels (p = 0.044), functionally the relaxation behavior was nearly the same. Biaxial testing and associated modeling highlighted the nonlinear (toe region of ~2–3% strain) and anisotropic (longitudinal direction linear modulus ~50 MPa, transverse ~2.5 MPa) tensile mechanical behavior of aponeurosis tissue. Comparisons of various constitutive formulations showed that a transversely isotropic Ogden approach balanced strong fitting (goodness of fit 0.984) with a limited number of parameters (five), while damage modeling parameters were also provided. Scanning electron microscopy showed a composite structure of highly aligned, partially wavy collagen fibrils with more random collagen cables for aponeurosis microstructure. Future work to expand microstructural analysis and use these data to inform computational modeling would benefit this work and the field.

腱膜是肌腱单元的坚硬的鞘状成分，在力传递和运动中起着至关重要的作用。腱膜在肌肉骨骼功能中具有明显的重要性，但是迄今为止，关于腱膜物质性质的研究相对较少。这项工作的目标是：1）进行拉伸应力松弛测试，2）进行平面双轴测试，3）对从1到2的数据进行计算建模，以及4）进行扫描电子显微镜检查以确定胶原纤维的组织。腱膜组织。应力松弛数据的粘弹性模型和统计分析表明，虽然应变率之间的弛豫率在统计上有所不同（p = 0.044），但功能上的弛豫行为几乎相同。双轴测试和相关模型强调了腱膜组织的非线性（趾部应变约为2-3％）和各向异性（纵向线性模量约为50 MPa，横向约为2.5 MPa）拉伸机械性能。各种本构公式的比较表明，横向各向同性的Ogden方法使用有限数量的参数（五个）平衡了强拟合（拟合优度0.984），同时还提供了损伤建模参数。扫描电子显微镜显示了高度对准的，部分波浪状的胶原纤维的复合结构，以及用于腱膜微观结构的更多的随机胶原蛋白电缆。将来扩展微观结构分析并使用这些数据为计算建模提供信息的工作将使这项工作和该领域受益。