  Simulation of assistive devices on pathological gait through musculoskeletal
models offers the potential and advantages of estimating the effect of the
device in several biomechanical variables and the device characteristics ahead
of manufacturing. In this study, we introduce a novel musculoskeletal modelling
approach to simulate the biomechanical impact of ankle foot orthoses (AFO) on
gait in individuals with spinal cord injury (SCI). Leveraging data from the
Swiss Paraplegic Center, we constructed anatomically and muscularly scaled
models for SCI-AFO users, aiming to predict changes in gait kinematics and
kinetics. The importance of this work lies in its potential to enhance
rehabilitation strategies and improve quality of life by enabling the
pre-manufacturing assessment of assistive devices. Despite the application of
musculoskeletal models in simulating walking aids effects in other conditions,
no predictive model currently exists for SCI gait. Evaluation through RMSE
showed similar results compared with other pathologies, simulation errors
ranged between 0.23 to 2.3 degrees in kinematics. Moreover, the model was able
to capture ankle joint muscular asymmetries and predict symmetry improvements
with AFO use. However, the simulation did not reveal all the AFO effects,
indicating a need for more personalized model parameters and optimized muscle
activation to fully replicate orthosis effects on SCI gait.
