Inclusion Criteria1. be between the ages of 18-85
2. able to give informed consent
3. be ≥ 6 months post diagnosis of unilateral cortical stroke and
4. have residual leg paresis.
Exclusion Criteria1. chronic low back or hip pain
2. substance abuse
3. head trauma in last 6 months
4. neurodegenerative disorder
5. any uncontrolled medical condition
6. any condition where knee extension contractions are contraindicated
7. people who are unable to follow multi step commands.
8. people who cannot walk ≥ 10 ft without physical assistance.
9. history of major psychiatric disorder
10. participant has had a myocardial infarction in the last year
11. participant has uncontrolled hypertension
12. participant is unable to contract knee muscles