Sensitivity Analysis of Muscle Parameters and Identification of Effective Muscles in Low Speed Lateral Impact at Just Below the Knee

Finite Element simulation of a lower extremity model is used to (1) determine which of the muscle parameters maximum force capacity (F_max), initial activation levels (N_a) and maximum muscle contraction velocity (V_max) affect ligament strains the most and (2) to identify which muscles affect the knee response the most in low speed, just below the knee, lateral impact. Simulations have been performed with F_max, N_a and V_max varying from their reference values. Sensitivity of ligament strains to variation in muscle parameters has been studied. It is observed that knee response is more sensitive to F_max and N_a than V_max. Amongst the muscles varied, reduction in the F_max and the N_a in the hamstring and the gastrocnemius muscles affects the knee ligament strains the most. The hamstring parameters significantly affects the ACL, the PCL as well as the MCL strains whereas, change in the gastrocnemius parameters affects only the MCL strain.