Usha Sinha1, Ali Moghadasi2, Ryuta Kinugasa3, Shantanu Sinha4
1Physics, San Diego State University, San Diego, CA, United States; 2University of California at San Diego, San Diego, CA, United States; 3Human Science, Kanagwa University, Kanagawa, Japan; 4Radiology, University of California at San Diego, San Diego, CA, United States
Strain rate describes the rate of regional deformation and does not require 3Dal tracking, or a reference state since strain rate is an instantaneous measure of kinematic properties. Further, measurement of strain rate in young and old subjects will help characterize and elucidate age related changes in muscle structure and function. The strain rate tensor orientation deviated significantly from the muscle fiber orientation in both young and old subjects and may be an index of structural integrity. The out-of-plane strain rate component was significantly increased in the older subjects indicating age related loss of structural integrity.