A new model of passive muscle tissue integrating Collagen Fibers: Consequences for muscle behavior analysis

Abstract

Mechanical properties of muscle tissue are crucial in biomechanical modeling of the human body. Muscle tissue is a combination of Muscle Fibers (MFs) and connective tissue including collagen and elastin fibers. There are a lot of passive muscle models in the literature but most of them do not consider any distinction between Collagen Fibers (CFs) and MFs, or at least do not consider the mechanical effects of the CFs on the Three-Dimensional (3-D) behavior of tissue. As a consequence, unfortunately, they cannot describe the observed stress-stretch behavior in tissue in which the reinforced direction is not parallel to the MF direction. In this research, a new passive muscle model is presented, in which the CFs are separately considered in the formulation: they are distributed along the MFs in a cross-shaped arrangement. Thanks to this new architecture, a mechanical reinforced direction can be proposed, in addition to the muscle main fiber direction. The passive biomechanical properties of the genioglossus muscle of a bovine tongue have been measured under uniaxial tensile tests. To characterize the 3-D response of the tissue, tests have been performed in different directions with respect to the MF direction. Moreover, a Constitutive Law (CL) has been proposed for modeling this behavior. In addition to our measurements on the bovine genioglossus muscle, results published in the literature on experimental data from the longissimus dorsi of pigs and the chicken pectoralis muscle were used to appraise the applicability of the proposed model. It is demonstrated that the proposed passive muscle model provides an accurate description of the fiber-oriented nature of muscle tissue. Also, it has been shown that using Finite Element Analysis (FEA) it might be possible to predict the angle θ between CFs and MF.

Exploring the Pathological Role of Collagen in Paravertebral Muscle in the Progression of Idiopathic Scoliosis

“…Mechanical properties of skeletal muscle are crucial in spinal stability, which is determined by its composition. Skeletal muscle is a combination of muscle fibers and connective tissue including collagen fibers [ 7 ]. Collagen fibers maintain the integrity of skeletal muscle by binding muscle fibers together and allow the transmission of muscular forces [ 34 ].…”

“…Mechanical properties of muscle tissue are crucial in the biomechanical balance of the human body [7]. The biomechanical characteristics of PVM has been suggested as being scoliogenic (inducing scoliosis) or counteracting scoliosis in the initial development and maintenance of IS [8,9].…”

Investigating Passive Muscle Mechanics With Biaxial Stretch

“…Gindre et al (2013) developed a microstructural model of a muscle fiber wrapped with a single family of dispersed ECM fibers to explore titin and ECM contributions. Yousefi et al (2018) showed how a similar model of the ECM as the only load bearing mechanism with two perfectly reinforcing fiber directions can describe the observed anisotropy in passively stretched bovine, porcine, and chicken muscle. Bleiler et al (2019) designed and formulated a passive constitutive model with dispersed collagen fibers surrounding muscle fibers that could be integrated into a finite element simulation.…”

“…fibers (Figure 2; Yousefi et al, 2018;Bleiler et al, 2019). This formulation attributes muscle fibers and the ECM as the main load-bearing constituents in passively stretched muscle (Smith et al, 2019).…”

“…While each of these studies present advantages for modeling the passive response of skeletal muscle, we have chosen to use a similar approach to Yousefi et al (2018) with the extension of the model to include ECM collagen dispersion and muscle fiber stiffness. After applying assumptions for the low-stiffness isotropic ground matrix (Wheatley et al, 2017a) and nearincompressibility (Takaza et al, 2012), this model required five parameters to describe the hyperelastic response -two for the muscle fibers (stiffness and non-linearity) and three for the ECM (stiffness, direction, and dispersion).…”