Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 52 12 2019 10 14 Simulation of Biceps Femoris Muscle Growth Based on Stretch Using a Multiscale Model Simulation of Biceps Femoris Muscle Growth Based on Stretch Using a Multiscale Model 3549 3566 3633 10.22060/mej.2019.15643.6175 FA Saeed Javadi Department of Mechanical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad Abdolrahman Jaamialahmadi Department of Mechanical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad 0000-0001-8747-2884 Ali Reza Danesh Mehr Mechanical Engineering, Tehran University Mohaddeseh Azadvari Tehran University of Medical Sciences Saeid Nekoonam Tehran University of Medical Sciences Journal Article 2019 01 17 Understanding the process of muscle tissue growth is important to professionals who <br />are involved in curing musculoskeletal disorders, physical medicine and rehabilitation specialists <br />and orthopedic surgeons. This article investigates the development of a musculoskeletal cell and also <br />determining the vulnerable areas of biceps femoris muscles due to passive strains applied on it. By <br />decomposing the deformation gradient tensor to two parts, the elastic and growth, the finite growth relations <br />have been applied for an isotropic hyperelastic muscle material behavior. Consequently, the continuum <br />relations were combined with the growth evolution equation whrer a series of mechanobiological <br />relations were obtained. To solve them, a FORTRAN user-defined material subroutine (UMAT) for the <br />finite element Abaqus software was written and executed. The biceps femoris – long head muscle was <br />simulated based on a 6-week period assuming as a cylinder with 10% increase in initial length. Results <br />of the simulation indicate that maximum strains occur in the surfaces, not inside the muscle. They reach <br />1.045 near the proximal muscle-tendon junction in the posterior layer and 1.06 in distal muscle-junction <br />in interior surface. Also, these results can help a correct and optimal treatment, patient’s rehabilitation <br />and orthopedic surgeries. Understanding the process of muscle tissue growth is important to professionals who <br />are involved in curing musculoskeletal disorders, physical medicine and rehabilitation specialists <br />and orthopedic surgeons. This article investigates the development of a musculoskeletal cell and also <br />determining the vulnerable areas of biceps femoris muscles due to passive strains applied on it. By <br />decomposing the deformation gradient tensor to two parts, the elastic and growth, the finite growth relations <br />have been applied for an isotropic hyperelastic muscle material behavior. Consequently, the continuum <br />relations were combined with the growth evolution equation whrer a series of mechanobiological <br />relations were obtained. To solve them, a FORTRAN user-defined material subroutine (UMAT) for the <br />finite element Abaqus software was written and executed. The biceps femoris – long head muscle was <br />simulated based on a 6-week period assuming as a cylinder with 10% increase in initial length. Results <br />of the simulation indicate that maximum strains occur in the surfaces, not inside the muscle. They reach <br />1.045 near the proximal muscle-tendon junction in the posterior layer and 1.06 in distal muscle-junction <br />in interior surface. Also, these results can help a correct and optimal treatment, patient’s rehabilitation <br />and orthopedic surgeries. https://mej.aut.ac.ir/article_3633_acf922154627f6788918f03c42b123cd.pdf