Personalisation of Plantarflexor Musculotendon Model Parameters in Children with Cerebral Palsy

Personalisation of Plantarflexor Musculotendon Model Parameters in Children with Cerebral Palsy

Veerkamp, Kirsten (Vrije Universiteit Amsterdam; Griffith University; Amsterdam Movement Sciences, Rehabilitation & Development)
van der Krogt, Marjolein M. (Vrije Universiteit Amsterdam; Amsterdam Movement Sciences, Rehabilitation & Development)
Harlaar, J. (TU Delft Biomechatronics & Human-Machine Control; Erasmus MC)
O’Brien, Thomas D. (Liverpool John Moores University)
Kalkman, Barbara (Liverpool John Moores University)
Seth, A. (TU Delft Biomechatronics & Human-Machine Control)
Bar-On, Lynn (Vrije Universiteit Amsterdam; Universiteit Gent; Amsterdam Movement Sciences, Rehabilitation & Development)

2022

Neuromusculoskeletal models can be used to evaluate aberrant muscle function in cerebral palsy (CP), for example by estimating muscle and joint contact forces during gait. However, to be accurate, models should include representative musculotendon parameters. We aimed to estimate personalised parameters that capture the mechanical behaviour of the plantarflexors in children with CP and typically developing (TD) children. Ankle angle (using motion capture), torque (using a load-cell), and medial gastrocnemius fascicle lengths (using ultrasound) were measured during slow passive ankle dorsiflexion rotation for thirteen children with spastic CP and thirteen TD children. Per subject, the measured rotation was input to a scaled OpenSim model to simulate the torque and fascicle length output. Musculotendon model parameters were personalised by the best match between simulated and experimental torque–angle and fascicle length-angle curves according to a least-squares fit. Personalised tendon slack lengths were significantly longer and optimal fibre lengths significantly shorter in CP than model defaults and than in TD. Personalised tendon compliance was substantially higher in both groups compared to the model default. The presented method to personalise musculotendon parameters will likely yield more accurate simulations of subject-specific muscle mechanics, to help us understand the effects of altered musculotendon properties in CP.

Achilles tendon
Biomechanical simulation
Calf muscles
Contracture
Muscle mechanics
Neuromusculoskeletal modelling
OpenSim
Subject specific
Triceps surae
Ultrasound

http://resolver.tudelft.nl/uuid:3605d6ed-7b28-4cc7-90a0-255b4fa9ac81

https://doi.org/10.1007/s10439-022-03107-8

0090-6964

Annals of Biomedical Engineering, 51 (2023) (5), 938-950

Institutional Repository

journal article

© 2022 Kirsten Veerkamp, Marjolein M. van der Krogt, J. Harlaar, Thomas D. O’Brien, Barbara Kalkman, A. Seth, Lynn Bar-On