Inclusion Criteria:  ≥18 years old no known neurological injuries. neurologically stable for >6 months (and >1 yr post stroke) medical clearance to participate unilateral ankle and/or wrist spasticity, confirmed by Modified Ashworth Scale (MAS) > 1 and the presence of spastic hyperreflexia  Exclusion Criteria:  motoneuron injury (i.e. the neurons that give rise to the axons innervating the muscles) with inadequate response to stimulation a cardiac condition ( history of myocardial infarction, congestive heart failure, pacemaker use, coronary artery disease, atrial fibrillation, congenital heart disease, uncontrolled hypertension) a medically unstable condition (including temporary infections and pregnancy) age <18 years old cognitive impairment sufficient to interfere with informed consent or successful completion of the protocol metal allergies needle phobias lymphedema over a limb (due to risk of infection/cellulitis) abnormal bleeding tendencies compromised immune system vascular disease uncontrolled diabetes history of epilepsy (as DDN generates strong somatosensory sensation) anxiety disorders or in distress botox injection in target muscle within 3 months prior to start of study