Research
I study how the human nervous system controls movement. I want to refine our understanding of how the spinal cord works to produce co-ordinated arm and leg movements during walking. I am very interested in applying basic neuroscience discoveries to target changes in the nervous system (neural plasticity) that can improve the rehabilitation of walking after neurological damage (particularly after stroke). My research has had an emphasis on the role reflexes play in functional coordination of the arms and legs. The methodologies applied in my research projects cross many boundaries and make use of the techniques of neurophysiology, biomechanics, motor behaviour, and exercise physiology.
There are three major themes that emerge from my research: 1) neural control of human rhythmic movement; 2) coordination of the arms and legs during locomotion; and 3) neuromuscular plasticity and motor recovery after stroke. Click on this to go to rehabneurolab.ca and read more about my research.
Neural control of rhythmic human movement
This theme actually forms the umbrella for my other research activities. You can read a bit more about this below and elsewhere, but let me give you the short answers before you move on. My work suggests that the neural control of rhythmic locomotion in humans is supported by spinal cord circuits just like found in other animals like the monkey, cat, rat, and turtle. Related to this point the activity of the arms helps support activity in the legs and vice versa. I like to say that “the arms give the legs a helping hand” when we walk. The last bit is that my work suggests that many of the connections that help us walk when we don’t have damage may be preserved after stroke and can be improved with rehabilitation and training.
Arm and leg coordination during walking
Many of my experiments are aimed at evaluating the extent to which the nervous system creates elementary units of coordination within and between limbs. In many of my studies I used different reflex pathways to reveal this coordination. Other studies emphasized the possible utility of these connections in coordinating the arms during rhythmic movement and all four limbs during complex tasks such as walking. Recent projects examined the extent to which sensory information is transferred via reflex pathways from the foot to the arms during walking. This is important not just for improving our understanding of arm and leg coordination, but also has application to research in older subjects in which balance control and coordination during walking are impaired, often as an outcome of sensory loss. Funding for these projects is provided by NSERC and the Heart and Stroke Foundation of Canada.
Neuromuscular plasticity and rehabilitation
Much of my work has focused upon describing mechanisms of coordination in reflex pathways during human movement. I am now building upon the concepts that I have established to evaluate the changes in this coordination as a result of exercise training, after injury (e.g. stroke or spinal cord injury), or after rehabilitative interventions. Earlier in my career I examined this issue of injury previously in stroke and this remains a current focus. Additionally some projects also address issues related to incomplete spinal cord injury. My work has shown that remote stimulation (i.e. from the cutaneous fields of the foot) evoke large responses in arm and leg muscles in stroke and this could provide another avenue for rehabilitative interventions. Further, the integrity of arm to leg linkages may be facilitated with training after stroke. Recently more of our work has been in evaluating the bilateral response to strength training of one arm or leg. This "cross education effect" of neuroplasticity is steadily increasing in emphasis in my lab and is funded by the Heart and Stroke Foundation of Canada (BC & Yukon).