Assessment of Stress Distributions in a Skeletal Muscle Affected by Post-Stroke Spastic Myopathy

The aim of this study is to evaluate stress distributions in the medial gastrocnemius muscle (GM) of patients with spastic myopathy after stroke. Shear wave elastography was employed to measure the shear modulus in three specific regions (upper, middle, and lower) of the muscle in six participants (three healthy and three post-stroke). These shear modulus measurements served as inputs for a finite element model to estimate stress distributions during uniform muscle stretching. The skeletal muscle was modelled as a hyperelastic, incompressible and inhomogeneous material. The results permitted to compare the healthy and post-stroke cases, showing that stress distributions tend to significantly increase in the post-stroke group, particularly in the middle region (+60%) and lower region (+13%). These results demonstrate the feasibility of estimating stress distributions using SWE data in post-stroke conditions, highlighting potential for further optimization of both experimental protocols and numerical models. These advancements could ultimately provide valuable insights into the clinical challenges associated with understanding spastic myopathy pathologies. • Shear modulus measured in the medial gastrocnemius of post-stroke patients. • Finite element analysis estimated stress distributions under uniform stretch. • Post-stroke muscles exhibited higher stress concentrations.