Computational modelling is an invaluable tool for investigating features of human locomotion which cannot be measured except for highly invasive techniques. Recent research has focussed on creating personalised musculoskeletal models using medical imaging. Although progress has been made, robust definition of two critical model parameters remains challenging; (i) tibiofemoral (TF) and patellofemoral (PF) joint motions, and (ii) muscle tendon unit (MTU) pathways and kinematics. The aim of this study was to develop a highly automated framework for the definition of personalised musculoskeletal models, consisting of personalised bone geometries, TF and PF joint models, and MTU pathways and kinematics. Informed from medical imaging, personalised rigid body 6 degree-of-freedom TF and PF joint models were created. Using atlas-and optimisation-based methods, personalised MTU pathways and kinematics were created with the aim of preventing MTUs penetrating bones and smooth MTU kinematics that follow literature patterns. This framework was deployed in Musculoskeletal Atlas Project Client for 6 participants, where 5 models with incremental personalisation were created. Three comparisons were made; (i) non-optimised and optimised models with nonpersonalised joint models; (ii) non-optimised and optimised models with personalised joint models; (iii) both aforementioned optimised models. Following optimisation, significant improvements were consistently shown in pattern similarity to literature data. Although not significant, improvements to all metrics were shown with reduced MTUs penetrating bone and increased kinematic smoothness. Comparing optimised models, no significant difference was identified for any evaluation metric, with a trend for more desirable results in the nonpersonalised joint models in most evaluation metrics.
Methods
Gait data testing and magnetic resonance imagingData were collected at Griffith University as part of an ongoing project (Ethics reference: PES/36/10/HREC). A subset of 6 participants were selected from a larger cohort to span a large range of age, height, and mass (Table 1). Participants had no history of musculoskeletal injury, trauma or lower-limb surgeries. Each participant provided their written and informed consent prior to undergoing comprehensive motion capture (MOCAP) and medical imaging sessions.Three-dimensional (3D) marker positions during a static calibration trial were converted from standard MOCAP format (i.e., .c3d) to standard OpenSim format (i.e., .trc) using MOtoNMS (Mantoan et al. 2015) for use in the MAP-Client.Each participant underwent magnetic resonance imaging (MRI) of their lower-limbs at a local radiology clinic (QScan Southport, QLD, Australia) performed on the preceding or same day as the MOCAP session. Axial T1-weighted 3D fast field echo sequences were acquired bilaterally from above the iliac crest to below the toes, while the participant lay supine in a 3 T
