Within the first year after stroke, approximately 38% of stroke survivors experience an increased resistance to movement, also called spasticity. One type of treatment that is approved for stroke survivors in Canada that could reduce spasticity is the injection of Botulinum toxin (BTX) into the affected muscle. While BTX reduces spasticity, there is limited evidence to show that BTX administration leads to functional improvements. This may occur because the outcomes aren't sensitive enough to detect change, some people may have better responses to BTX, or because BTX hasn't been paired with the right exercises to improve function. The aims of this research are: i) to determine if there is a way of improving the markers that measure change in response to treatment; and ii) to identify the ideal type of exercise that should be paired with BTX to allow the drug to have it greatest effect.

There are two primary research questions: a) What are the measures that will indicate whether a person with post-stroke spasticity will benefit from BTX therapy? It is hypothesized that EMG latency and amplitude, for those who best respond to BTX, will differ from those who demonstrate a weaker response to BTX; b)What is the ideal training approach for improving muscle function in stroke survivors receiving BTX injections? It is hypothesized that a training protocol that focuses on optimizing specific muscle activation patterns will demonstrate better outcomes than a training program designed to improve function.

Inclusion Criteria:

• >120 days post first ischemic stroke
• Unilateral spasticity (MAS ≥ 1) of the wrist or elbow
• >18 years of age
• Medical referral for focal BoNT-A injections
• Residual active control of the wrist or elbow

Exclusion Criteria:

• Underlying neuromuscular disorders (i.e. ALS, neuropathies, myasthenia gravis)
• Inability to provide informed consent or communicate in English
• Bilateral paresis/spasticity
• Contractures
• Prescribed anti-spastic medication