—PFJ contact force waveforms (dashed line) for internal approach (top), external approach (middle), and Brechter model (bottom) for a single trial (trial 10). The vertical dot-dash line marks the transition between stance to swing phase. Target contact forces (solid line) are generated by a musculoskeletal model (COMAK). Root mean square errors of 3.81, 7.23, and 10.2 N/BW for the internal approach, external approach, and Brechter model, respectively. BW indicates body weight; COMAK, Concurrent Optimization of Muscle Activations and Kinematics; PFJ, patellofemoral joint.

Citation: Journal of Applied Biomechanics 39, 6; 10.1123/jab.2022-0247