Inclusion Criteria:  age 7 to 21; has SKG diagnosed with brain injury including but not limited to Cerebral Palsy, Stroke,Traumatic Brain Injury; ability to walk on a treadmill without assistive devices based on parent/guardian report and/or treatment history; the cognitive development is at the level needed to: understand and follow instructions, answer questions, be able to understand the purpose of the study and the activities involved.  Exclusion Criteria:  Botulinum toxin treatment less than 16 weeks before initiation of the study Recent or concurrent treatment that might interfere with the study.