Stroke is the leading cause of disability. Spasticity is present in approximately 1/3 of stroke survivors. It remains a clinical challenge for clinicians, patients and their care providers. Botulinum toxin (BoNT) injection is the first line of management of focal spasticity through blockade of neurotransmitter release at the neuromuscular junction (i.e., innervation zone) of spastic muscles. The efficacy of BoNT therapy depends on the location of injection needle tip and its distance from the innervation zone. This talk will discuss how innervation zone is localized via surface EMG and its relation to BoNT injection.