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Updated: Jul 3, 2026

An in vivo Rodent Model of Contraction-induced Injury and Non-invasive Monitoring of Recovery
Published on: May 11, 2011
Mechanics of muscle injury induced by lengthening contraction
Yingxin Gao1, Alan S Wineman, Anthony M Waas
1Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109-2125, USA.
Abstract:
Skeletal muscle is composed of two primary structural components, contractile myofibrils and extracellular matrix (ECM). The myofibrils adhere to the surrounding endomysium through the basal lamina, sarcolemma and dystrophin, and dystrophin associated glycoprotein (DAG). In this study, a novel shear lag type model is developed to investigate the mechanics of injury to the single muscle fiber due to lengthening contractions. A single muscle fiber is considered as a composite system with reinforced by the contractile myofibrils. The lateral linkages between myofibril and endomysium is modeled as a zero thickness coating layer, that could be injured under high interfacial shear stress. The results shows that the degree of the muscle injury is correlated to the magnitude of the passive stretch during the contraction. Dystrophic muscles are more susceptible to contraction induced injury due to lack of DAG complex in lateral linkage.
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