Sensitivity of musculoskeletal models to scaled-generic knee kinematic errors

Musculoskeletal muscle and joint contact forces during activity are used in research and clinical contexts including prosthesis design and injury prevention. Most often, a generic musculoskeletal model is scaled to participant anatomy using corresponding measurements of segment length. However, it is unclear how scaled-generic knee kinematic errors affect muscle and joint contact force calculation. Recently, subject-specific knee kinematics were obtained from patient anatomy using a spatial parallel mechanism while segment lengths, motion data and bone geometry can be obtained using gait analysis and computed-tomography (CT). We assessed the sensitivity of musculoskeletal models to scaled-generic knee kinematic errors by combining subject-specific knee kinematic modelling with earlier motion data and CT images.