To remain functional throughout life, the control of locomotion must be adjustable to changes in body size and muscle strength as well as to the demands of the environment. However, part of the neural circuits at the basis of this life-long motor learning are specific to this movement. Therefore, we cannot always generalize from what is known from experiments performed “at rest” to what happens during walking. This presentation will summarize several experiments performed in healthy participants and neurological populations where a robotic ankle orthosis was used to study the signals that trigger our ability to adapt human gait. By imposing controlled disturbances during walking and by interrogating sensorimotor pathways using different neurophysiological methods (TMS, reflexes, etc.), this approach allowed us to better understand adaptive loco-motor plasticity and to reveal some of the underlying neural mechanisms. Moreover, as locomotor rehabilitation is often performed in the presence of pain, we used this model to also assess the effect of experimental pain (cutaneous and muscular) on locomotor learning. Our results demonstrate that the use of robotic tools can be very powerful to help understanding human locomotor control in health and disease and to develop / optimize locomotor rehabilitation paradigms.
While the neural control of locomotion differs from that of other types of voluntary movements, it is nevertheless capable of motor adaptation and motor learning.
Using repeated external perturbations (“force fields”) is a good model to trigger locomotor learning.
The motor cortex and skin afferents contribute to the underlying neural processes.
Exposure to pain during the learning process affects retention more than acquisition.
Sensory inputs are gated during gait, and locomotor training after spinal cord injury can help restoring normal proprioception.
Robotic tools are useful to help understanding locomotor control/ learning in humans
This work was supported by the Canadian Institutes for Health Research (CIHR) and the Natural Sciences and Engineering Research Council of Canada (NSERC).
Dr. Bouyer is a Full Professor in the Department of Rehabilitation at Laval University, the Director of the Neuroscience Research Center and a Researcher at the Center for Interdisciplinary Research in Rehabilitation and Social Integration (CIRRIS). His research program focuses on motor control and motor learning. Most of his research projects are carried out in interdisciplinary teams that combine health sciences and engineering, covering many facets of rehabilitation research. His research interests include understanding the neural circuitry underlying human gait control, remote sensing / telemetry in real-world environments, improving clinical tests using wearable sensors, and developing new robotic technologies and software for rehabilitation.