Investigating a non-invasive method for determining muscle fiber composition

• Main Author: Treers, Laura
• Other Authors: Anette Hosoi.
• Format: Others
• Language: English
• Published: Massachusetts Institute of Technology 2019
• Subjects: Mechanical Engineering.
• Online Access: http://hdl.handle.net/1721.1/119934

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018. === Cataloged from PDF version of thesis. === Includes bibliographical references (pages 39-40). === This study aims to explore a new method for analysis of muscle fiber type, using data collected from weightlifts on a leg press. A dynamic muscle model is developed, which utilizes the Descherevskii kinetic theory in combination with a muscle "matrix" model to predict net muscle contraction forces and velocities as a function of fiber type. These relationships are integrated into a dynamic model for lifting a weight, allowing for the derivation of joint trajectories in time, from the molecular properties of muscle. The model-predicted velocity trajectories for the lift are compared with curves obtained experimentally from weightlifting trials. Longer lifts with slower peak velocities indicate higher ratios of slow-twitch fibers, and shorter lifts with greater peak velocities indicate higher ratios of fast-twitch fibers. This idea is supported by both the model results and in experimental trends. With further refinement of experimental protocols, the leg press test has the potential to be a powerful training tool for athletes-both to compare their muscle makeup with other athletes, and to track their own progress over the course of their training. === by Laura Treers. === S.B.