Clinical Outcomes: Motor Function. Expert co-investigators have designed a rigorous approach to motor outcome assessment, overcoming some of the limitations of existing hemiparetic CP trials. Multidimensional evaluations will assess body structure and function, activity and participation domains of the WHO International Classification of Functioning, Disability and Health (ICF). Tools with established clinimetric properties were selected to evaluate diverse upper extremity functions relevant to daily living in children. Measures had to be both child/family friendly and time sensitive. The investigators will measure uni- and bi-lateral function for normative data, evaluation of bimanual functions, and safety (including screening for changes in unaffected hand function). Tests will be performed by the same experienced, blinded, non-treating site OT and video-taped for quality assurance and offline analysis. Motor outcomes are measured at baseline, and 1 week, 2 months and 6 months post-intervention.