The investigators will test whether an intervention called ischemic conditioning can improve paretic leg motor function in chronic stroke subjects.

This study will study ischemic conditioning (IC) as an intervention to improve motor function post-stroke. IC is a well studied, well tolerated intervention which has been shown to improve regional blood flow, motor neuron excitability and muscle function in multiple patient groups and in young, healthy subjects. Because IC targets three physiological systems which are all affected by stroke, the investigators hypothesize that repeated bouts of IC will result in improved motor function of the paretic leg.

Inclusion Criteria:

1. 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 Criteria:

1. 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