Diffusion Tensor MRI Analysis of Hamstring Muscle Architecture Following 9-Week Eccentric Training

Motivation: To unveil the mechanism of preventative action offered by eccentric exercise regimes towards hamstring strain injuries, understanding muscle adaptations at microstructural level is crucial. Goal(s): To investigate microstructural adaptations in hamstring muscles post 9-weeks of eccentric NHE using diffusion tensor imaging (DTI) metrics like axial (AD), mean (MD), and radial (RD) diffusivities. Approach: Ten participants underwent Dixon and DTI scans pre and post 9-weeks of supervised eccentric NHE training. Results: Post intervention, significant increases in AD, MD, and RD were observed, suggesting muscle hypertrophy, exercise-induced microtrauma, structural remodelling and potential Type II muscle fiber adaptations. Impact: This study explored the ability of DTI to provide novel insights into microstructural adaptations of hamstring muscle to eccentric training. The findings highlight hypertrophy, structural remodelling, and fiber type shifts, advancing injury prevention and rehabilitation strategies through a fiber-level perspective.