Bucknell University

Eri: a Computational and Experimental Approach to Establishing Multiscale and Multiphasic Structure-function Mechanisms of Muscle Stiffness -this Engineering Research Initiation (ERI) Award Supports Research That Will Create a Model of Muscle Behavior at Multiple Scales. Muscle Is Responsible for Providing the Power That Is Necessary to Live Our Daily Lives ? Walking, Communicating, and Breathing Are All Possible Thanks to Skeletal Muscle. However, Muscle Injury, Neuromuscular Disease, and Other Impairments Can Reduce a Person?s Mobility and Cause Significant Pain Because the Muscles Are Too Stiff. This Project Is to Investigate How the Stiffness and Biology of Healthy Muscle Is Different From That of Impaired Muscle. in Particular, It Is Currently Unknown How Molecules That Compose Skeletal Muscle Contribute to the Mechanical Properties, Particularly to Muscle Stiffness. the Project Will Investigate How Three Key Parts of Skeletal Muscle Contribute to Muscle Stiffness ? a) Muscle Cells, B) a Web-like Tissue Called the Extracellular Matrix, and C) the Cellular Liquids in Muscle. the Research Team Will Use Experimental Testing Complemented by Computer Models to Generate Data. This Data Will Help Scientists and Clinicians Better to Understand What Specific Mechanisms of a Disease Change Muscle Stiffness. the Results Will Contribute to Improving Treatments for People Who Suffer From Such Muscle Conditions. This Grant Also Will Support Educational Outreach to Mentor a Diverse Group of Undergraduate Student Researchers and Support Their Professional Development in Careers in the Sciences. This Work Will Establish Critical Structure-function Mechanisms in Passive Skeletal Muscle by Leveraging Multiscale Materials Testing and Finite Element Analysis. While Changes to Muscle Stiffness From Impairments Correlate to Measurements Such as Collagen Content and Type, Predicting the Hyperelastic, Anisotropic Material Properties of Muscle in Vivo Is Not Possible. the Research Team Will Perform Multi-axial Materials Testing on Individual Muscle Fibers, Muscle Tissue, and Whole Muscle Under Both Tensile and Compressive Conditions. These Experimental Data Will Comprise the Most Comprehensive Set of Muscle Material Properties Collected to Date and Will Be Used for the Calibration and Validation of a Multiscale, Biphasic, Homogenized Finite Element Model of Muscle Tissue That Links Microstructural Form to Macro Function. This Model Can Then Be Used in Future Efforts to Study How Microstructural Changes to Muscle Tissue Alter Muscle Material Properties and Thus in Vivo Function. This Award Reflects NSF'S Statutory Mission and Has Been Deemed Worthy of Support Through Evaluation Using the Foundation's Intellectual Merit and Broader Impacts Review Criteria.