THE EFFECTS OF CONSTRAINING OPENSIM INVERSE KINEMATICS TO A BONE PIN MARKER DEFINED RANGE

Abstract

The aim of this study was to apply bone pin kinematic constraints to an OpenSim model to determine differences in knee joint kinematics and kinetics beween the constrained and unconstrained solutions. In vivo data from healthy, anterior cruciate ligament deficient and reoonstructed patients completing a forward jump lunge were combined with bone pin data from a past study to redefine ranges that the knee degrees of freedom were constrained to. Differences between the constrained and unconstrained solutions existed for all participants at various points of the jump lunge movement, especially at the time of impact. Soft tissue artifact was most apparent in transverse plane translations. In conclusion, musculoskeletal modelling based solely on surface marker positions is inherently affected by soft tissue artifact and thus, results from these analyses should be interpreted with caution.