Evaluation of a modelling workflow to obtain subject specific spine geometry for sitting postures

A three steps modelling workflow is introduced to obtain personalised spine models at standing and sitting postures. Initially, a principal component analysis based model is employed to locate internal points in a standing posture, using the external trunk shape as input. Then, these estimated internal points are used to personalise a generic anatomical spine template at a standing posture, using the AnyBody Modeling System. The personalised spine model is repositioned into a sitting posture using anatomical landmarks (AL). The proposed workflow was verified with MRI scans obtained from nine participants in standing and sitting postures. The mean prediction error of the spine joint centres was 18.7 (3.6) mm for the standing and 13.1 (5.0) mm for the sitting posture when all AL were used. The suggested workflow can provide accurate spine models at sitting postures when enough information (AL) is available regarding the spine, for the model positioning.