AB Gait Estim Neurophysiology

Inclusion Criteria: * 18-65 years * Able-bodied (healthy without any physical disability, neurological, orthopedic, or other medical disorder affecting walking or study protocol participation) * Ability to walk \>10m overground and for 1 minute on a treadmill * Ability to follow 3-stage commands and provide informed consent. Exclusion Criteria: * Self-reported history or evidence of orthopedic or physical disability * History or evidence of neurological pathology * Pregnancy (female) * Uncontrolled hypertension * Cardiac pacemaker or other implanted electronic system * Presence of skin conditions preventing electrical stimulation setup * Impaired sensation in the left upper limb. * Bruises or cuts at the stimulation electrode placement site * Concurrent enrollment in rehabilitation or another investigational study. * History or evidence of orthopedic or physical disability interfering with study procedures * History or evidence of neurological pathology or disorder * Severe uncontrolled medical problems (e.g., hypertension, cardiovascular disease, rheumatoid arthritis, active cancer or renal disease, epilepsy) that may interfere with study procedures * Contraindications to TMS such as metal implants, medications that can increase cortical excitability, unexplained dizziness in the past 6 months