Contributions of muscle mechanics and sensorimotor control to agile locomotion

Humans and animals navigate complex terrain seemingly effortless.

This is in stark contrast with even the most performant robots, illustrating that walking over complex terrains is by no means trivial. Our neuromusculoskeletal system is equipped with mechanisms that allow us to recover from unexpected perturbations. Two key mechanisms are muscle intrinsic mechanics and sensory-driven feedback control.

Immediate changes in muscle force upon a perturbation allow the body to respond fast to sudden perturbations through quick-acting muscle mechanical responses.

Feedback responses, slower due to transmission delays, are also critical to stability as they are more flexible whereas muscle mechanical responses are determined by feedforward control and muscle properties.

We do not yet know how these pathways interact to help us maintain agility and robustness, in the presence of external perturbations, or in the case of sensory loss. I aim to gain novel insights into how muscle mechanics and sensory feedback allow agile locomotion across conditions.

I will unravel fundamental principles governing relative contributions of these mechanisms, using a blended experimental- and computational approach. I already collected a unique experimental dataset that I will combine with physics-based simulations.

I will use novel approaches to predict locomotion patterns and feedforward and feedback control by optimizing performance criteria in presence of sensorimotor noise without relying on experimental data.

Validation of simulation to experimental data allows us to evaluate which performance criteria and muscle properties drive observed interactions between muscle mechanics tuned by feedforward and feedback control.

As many neurological disorders impair stable locomotion, fundamental insights obtained through my project have potential to inform treatments.

Lastly, novel insights in locomotor neuromechanics inspires designs of legged robots and prosthetics to assist during locomotion.