Imaging-based musculoskeletal models alter muscle and joint contact forces but do not improve the agreement with experimentally measured electromyography signals in children with cerebral palsy

•We compared generic with medical imaging-based musculoskeletal models.•MRI-based models do not improve the estimation of muscle activation.•MRI-based models have a big impact on joint contact forces.•Altered joint contact forces do not necessarily mean accurate muscle activations.