Characterising and comparing musculoskeletal (MSK) modelling outputs during gait in typical clinical cohorts

Musculo-skeletal (MSK) modelling enables calculation of additional outcomes compared to traditional clinical three-dimensional gait analysis (3DGA), with potential to inform and enhance treatment decision-making and evaluate outcomes. However, translation to routine practice has been limited due to the complexities of MSK modelling in clinical populations. The overall aim of this project is to facilitate the introduction of MSK modelling into a paediatric clinical gait analysis service, characterising and defining the reliability of outputs of normalised muscle-tendon length (nMTL) and velocity (nMTV) for both typical and clinical datasets, using newly available MSK models and approaches. Clinical cohorts are identified from retrospective clinical 3DGA data from children and young people (CYP) with Cerebral Palsy (CP) Diplegia and Hemiplegia, grouped and described based on sagittal plane kinematic features.

A recently released generic MSK model with properties based on latest research is identified for use, further modified based on the approach of previous publications, to reflect established 3DGA modelling. This enables comparison of kinematic outputs, facilitating understanding and interpretation of subsequent MSK modelling results. Processing techniques devised are presented and justified, along with the choice of ten muscles to explore within this project. For these muscles, thresholds for minimal level of detectable change (MLDC) in nMTL and nMTV outputs are determined from reliability studies.

Following characterisation of nMTL and nMTV in both typical and clinical datasets, statistically significant differences between groups and typical data are identified across the gait cycle utilising Statistical Parametric Mapping (SPM), to provide an understanding of discriminant validity. Differences are interpreted in context with known muscle function and kinematic outputs, with an assessment of convergent validity through comparison to clinical examination findings. Data from the Semimembranosus muscle is presented as an exemplar, including exploring responsiveness with a case-study of surgical hamstring lengthening.

Throughout, the presented work highlights the challenges and potential of implementing MSK modelling in clinical gait laboratories. The limitations of the devised approaches and recommendations for future development are discussed, with the aim of facilitating implementation of MSK modelling in clinical gait environments.

Outputs

DClinSci Thesis: https://research.manchester.ac.uk/en/studentTheses/characterising-and-comparing-musculoskeletal-msk-modelling-output/

Presentation at Clinical Movement Analysis Society AGM 2025: https://cmasuki.org/wp-content/uploads/2025/07/Oxford-CMAS-2025.pdf

Presentation at European Society of Movement Analysis in Adults and Children AGM 2025: https://doi.org/10.1016/j.gaitpost.2025.07.200