Linking cortex and contraction-Integrating models along the corticomuscular pathway

Front Physiol. 2023 May 10:14:1095260. doi: 10.3389/fphys.2023.1095260. eCollection 2023.

Abstract

Computational models of the neuromusculoskeletal system provide a deterministic approach to investigate input-output relationships in the human motor system. Neuromusculoskeletal models are typically used to estimate muscle activations and forces that are consistent with observed motion under healthy and pathological conditions. However, many movement pathologies originate in the brain, including stroke, cerebral palsy, and Parkinson's disease, while most neuromusculoskeletal models deal exclusively with the peripheral nervous system and do not incorporate models of the motor cortex, cerebellum, or spinal cord. An integrated understanding of motor control is necessary to reveal underlying neural-input and motor-output relationships. To facilitate the development of integrated corticomuscular motor pathway models, we provide an overview of the neuromusculoskeletal modelling landscape with a focus on integrating computational models of the motor cortex, spinal cord circuitry, α-motoneurons and skeletal muscle in regard to their role in generating voluntary muscle contraction. Further, we highlight the challenges and opportunities associated with an integrated corticomuscular pathway model, such as challenges in defining neuron connectivities, modelling standardisation, and opportunities in applying models to study emergent behaviour. Integrated corticomuscular pathway models have applications in brain-machine-interaction, education, and our understanding of neurological disease.

Keywords: biophysical modelling; corticomuscular; corticospinal; motor control; neuromuscular; proprioception.

Grants and funding

This research was partially funded by the New Zealand Ministry of Business, Innovation and Employment’s (MBIE) Catalyst Strategic Fund (project “12 Labours”) and partially by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy—EXC 2075—390740016 and projects “Priority Program 2311” (ID 465243391) and “Soft Tissue Robotics” (ID GRK2198). Additional funding was also provided by Callaghan Innovation, New Zealand’s innovation agency (ID SMACH1801), the Li Ka Shing Foundation, the Friedlander Foundation and the University of Auckland.