Torsion Tool: An automated tool for personalising femoral and tibial geometries in OpenSim musculoskeletal models

Common practice in musculoskeletal modelling is to use scaled models based on a healthy adult, but this does not consider subject-specific geometry, such as tibial torsion and femoral neck-shaft anteversion angles (NSA AVA). The aims of study were (1) develop an automated tool for creating OpenSim with NSA AVA, (2) evaluate the component, (3) release open-source. Torsion Tool (https://simtk.org/projects/torsiontool) MATLAB-based that requires individual’s torsion, AVA estimates input rotates corresponding bones associated muscle points generic model. Performance was evaluated comparing femur personalised femurs manually segmented golden standard six typically developing children thirteen cerebral palsy. generated geometries closer segmentations, lower maximum (?19%) root mean square (?18%) errors higher Jaccard indices (+9%) compared femurs. Furthermore, resulted larger improvements participants deviations. allows automatic, fast, user-friendly way personalising geometry Personalisation expected be particularly relevant pathological populations, will further investigated by evaluating effects simulation outcomes.