DTI and Fiber Tracking Study of the Effects of Aging on Musculoskeletal Architectural and Functional Parameters

Sanghamitra Sinha¹, Ryuta Kinugasa², ³

Muscle force output is affected severely by the aging process through its dependency on various musculoskeletal (MSK) architectural and physiological factors. In six senior and six young subjects, MSK diffusion tensor imaging (DTI) and fiber tractography was used to non-invasively investigate age-related microarchitectural changes in muscle compartments of the lower leg. Analysis of the DTI parameters revealed that λ3 decreased significantly with age in the plantarflexors. FA increased with age in all muscles. Finally, a decrease of MG fiber pennation angle by ~30% with age provided a partial explanation for the significant loss of muscle force output in the elderly.