RECOVERY FROM STROKE
Regaining the ability to walk in their community is commonly the most cited goal of people post-stroke with hemiparesis, making the rehabilitation of walking balance of paramount importance.
1. Effectiveness of Fast muscle Activation and Stepping Training (FAST) on balance and mobility post-stroke
Given that rehabilitation is the primary treatment for individuals recovering from stroke, it is essential that innovative exercise regimes are developed and examined for their ability to effect change in balance and mobility. The use of fast movements as an intervention to retrain walking balance showed the capacity to induce short-term changes in the muscle activation necessary for balance and mobility. The effectiveness of the exercise in evoking longer-term changes in function or physiological responses will be determined using 6 week retraining program.
2. Evaluation of motor recovery after stroke using an innovative High Density Surface Electromyography (HDS-EMG) technique
Many stroke survivors have residual sensorimotor deficits that impact negatively on balance and quality of life. Recently, considerable attention has been paid to neuroplastic changes in the brain that occur with rehabilitation interventions. It is important to investigate the capacity for remodeling at the level of the muscle after stroke. Surface electromyography has been used for decades to understand muscle activation patterns. Typically a single set of electrodes is placed over a muscle group to give an indication of the level of muscle activation. New High Density Surface Electromyography (HDS-EMG) technology developed at the Laboratory of Engineering of Neuromuscular System and Motor Rehabilitation (LISiN) in Turin, Italy has the capacity to determine the temporal and spatial patterns of muscle activity, e.g. to generate a map of the activation pattern across the different muscles. Physiologically relevant changes in the location of muscle activation, overtly not perceived by conventional surface electrodes, provide a more comprehensive way of evaluating the muscle impairment after stroke and the effects of interventions aimed at motor recovery.
POSTURAL ACTIVITIES
Control of human standing posture: The main objective of this research program is to advance the understanding of the neural control of force production and movement by investigating the regional activation of populations of motor units in a functional standing task as a model instead of conventional isometric or isotonic voluntary contractions.
1. Investigation of regional activation of the ankle plantarflexor muscles during standing perturbations.
The physiological significance of regional activation and the influence of perturbation direction and size, and fatigue on the HDS-EMG is explored.
2. How is spinal motoneuron excitability controlled during standing?
Peristimulus frequencygrams (PSF) are used to estimate the excitatory and inhibitory postsynaptic potentials (EPSP or IPSP) in ankle plantarflexors. By means of HDS-EMG the discharge of several simultaneously active motor units in ankle plantarflexors are recorded. The signal is subsequently decomposed using sophisticated decomposition software.
3. Is there a cortical contribution to regional activation during standing perturbations?
Corticospinal coherence is evaluated using electroencephalography (EEG) and HDS-EMG of the ankle plantarflexors.
PATELLOFEMORAL PAIN SYNDROME
Muscle activation in patellofemoral pain syndrome: The source of the knee pain is not clear: some studies show that people with knee pain contract their quadriceps muscle differently from healthy people, while others showed abnormalities primarily in people’s hips and feet. In this study, we investigate how individuals with patellofemoral pain syndrome activate their quadriceps muscle using high-density surface electromyography.
1. Is quadriceps dysfunction common in individuals with patellofemoral pain?
Using high-density surface electromyography, the coordination of regions within vastus medialis and lateralis is evaluated and compared between individual with patellofemoral pain and healthy controls.
2. Is quadriceps dysfunction related to knee strength or hip/foot posture?
We will also determine if clinical tests commonly used by physiotherapists can differentiate people with knee pain and quadriceps dysfunction from those without quadriceps dysfunction.
FUNDING SOURCES
Natural Sciences and Engineering Research Council
Heart and Stroke Foundation of Canada
Canada Foundation for Innovation
Physiotherapy Foundation of Canada (CAMPT Founders Award)