The study team is recruiting 20 adults with spasticity due to chronic stroke and 20 adults with no neurological injuries for a 4 day study over 1 week. In people with chronic stroke, one of the most common and disabling problems is spasticity (increased muscle tone or muscle stiffness). The purpose of this research study is to examine effects of dry needling on the nervous system (pathways between the muscle, spinal cord, and brain) in people with spasticity due to chronic stroke. Dry needling is a procedure in which a thin, stainless steel needle is inserted into your skin to produce a muscle twitch response. It is intended to release a knot in your muscle and relieve pain.

The total study duration is 4 visits over one week. The first visit will take about 1.5 hours, during which the study team will determine the best electrode placement and create a removeable cast of your arm or leg to aid in placing electrodes in the next visits. The second visit will take about 3 hours, during which dry needling will take place, and the fourth and fifth visits will take about 1.5 hour. During all visits you will be asked to participate in examinations of reflexes (muscle responses to non-invasive nerve stimulation) and arm/leg function.