The purpose of this clinical trial is to evaluate whether Transcutaneous Electrical Nerve Stimulation (TENS) is effective in reducing spasticity in adults with post-stroke spasticity. The primary research question is whether TENS can reduce the severity of spasticity. The effectiveness of TENS will be assessed by comparing spasticity-related outcomes measured before, during, and after the intervention. Participants will first undergo a one-hour baseline monitoring period, during which assessments will be conducted at 10-minute intervals. This will be followed by a 30-minute TENS intervention and a two-hour follow-up period, with assessments performed every 10 minutes. One participant will repeat this protocol once daily for three consecutive days, whereas the remaining three participants will undergo the procedure on a single occasion.