A Poroelastic Model of Skeletal Muscle Tissue Used to Predict Intramuscular Pressure

Many single-phase, solid mechanics computational models of skeletal muscle have been created based on the assumptions that skeletal muscle is hyperelastic, transversely isotropic,^1,2 and isovolumic. However, muscle has also been observed to have non-linear time-dependent behaviors that can be modeled using viscoelasticity or poroelasticity. The inherent viscoelasticity of muscle may not fully explain the time-dependent nature that may arise from extracellular fluid filtration³ and redistribution⁴ within the tissue. Further, intramuscular pressure (IMP) has been shown to have a heterogeneous distribution in muscle. This may be attributable to the movement of extracellular fluid, but the mechanisms of fluid redistribution are not completely understood. While a viscoelastic model may predict time-dependent responses of skeletal muscle, viscoelastic theory does not explain underlying causative tissue behaviors.⁵