To compare the effect of constraint induced movement therapy (CIMT) vs. treadmill training only on walking function in individuals post-stroke, a 6 week, single-blind, randomized training study will be conducted with three assessments of gait to determine the training effect. Subjects will be randomized to either the CIMT or treadmill training only groups at the initial test. Following the initial test, individuals from the 2 groups will undergo intensive locomotor training. Training will be performed 3 times per week for 6 weeks with the training time for each visit set to 45 minutes as tolerated. Data collection will proceed until 36 subjects from 2 groups have been trained.

To determine the effect of constraint induced movement therapy (CIMT) on locomotor function in individuals post stroke. In order to compare the effect of CIMT vs. treadmill training only on walking function in individuals post-stroke, a 6 week, single-blind, randomized training study will be conducted with three assessments of gait to determine the training effect. Subjects will be blocked by gait speed into slow (< 0.4 m/s) or fast (≥ 0.4 m/s) subgroups and randomized to either the CIMT or treadmill training only groups at the initial test. Following the initial test, individuals from the 2 groups will undergo intensive locomotor training. Training will be performed 3 times per week for 6 weeks with the training time for each visit set to 45 minutes as tolerated, excluding set up time. Data collection will proceed until 36 subjects from 2 groups have been trained.

Inclusion Criteria:

1. age between 21 and 75 years;
2. history of unilateral, supratentorial, ischemic or hemorrhagic stroke;
3. no prior stroke;
4. demonstration of impaired walking function (self-selected walking speed ≤ 0.80 m/s);
5. able to stand and walk (>10 meters) without physical assistance.

Exclusion Criteria:

1. significant cardiorespiratory/metabolic disease;
2. other neurological or orthopedic injury that impairs locomotion;
3. scores on the Mini Mental Status examination < 24;
4. stroke of the brainstem or cerebellar lesions;
5. uncontrolled hypertension (systolic > 200 mm Hg, diastolic > 110 mm Hg);
6. botox injection within 6 months of starting the study.

Outcome measures of each subject will be evaluated before training, after 6 weeks of training, and at 8 weeks after the end of training by a physical therapist who is blinded by subject group assignment, and subjects will be requested not to disclose his/her group assignment to this physical therapist.