Ankle Robotics for Error Augmentation After Stroke

The goal of this pilot clinical trial is to test whether training with a portable ankle robot improves ankle push-off and walking speed in adults with chronic stroke who have ankle weakness. The study will also evaluate whether the device is safe and practical to use during walking rehabilitation. The main questions it aims to answer are: Does training with the portable ankle robot improve paretic ankle propulsion during walking? Does training with the portable ankle robot improve walking speed at self-selected and fast walking speeds? Participants will: Complete 30 training sessions of treadmill and overground walking while wearing the portable ankle robot, 3 to 4 times per week over 8 to 9 weeks Complete walking and movement assessments before training, after 15 sessions, and after 30 sessions Walk at self-selected and fast speeds while researchers measure ankle propulsion, gait symmetry, and walking speed

Inclusion Criteria: * Chronic stroke, more than 6 months post-stroke * Clinical evidence of hemiparetic gait * Ankle dorsiflexion and plantarflexion strength on the affected side graded 1/5 (trace contraction) to 4/5 (reduced strength) on manual muscle testing * Able to independently complete the 10-Meter Walk Test at a walking speed less than 1.0 m/s, with or without an assistive device Exclusion Criteria: * Self-reported unstable angina, myocardial infarction within the past 3 months, congestive heart failure (NYHA Class II), or hemodynamically significant valvular disease * Self-reported hypertension that is a contraindication to routine physical therapy (greater than 160/100 mmHg on two assessments) * Self-reported hospitalization within the past 3 months for severe medical illness * Self-reported symptomatic peripheral arterial occlusive disease * Self-reported orthopedic conditions or chronic pain that significantly alter gait function * Self-reported pulmonary or renal failure * Self-reported active cancer * Self-reported history of a non-stroke neuromuscular disorder restricting gait * Aphasia or cognitive functioning that confounds participation, defined as unable to follow two-step commands or by judgment of the evaluating therapist * Self-reported history of cerebellar stroke or observable cerebellar signs * Self-reported botulinum toxin prescribed for the lower extremities within the previous 3 months