A. Primary Objective Motor Outcome: Assisting Hand Assessment (AHA). This is the established standard for the objective quantification of bilateral hand function in children with hemiparetic CP. This Rasch-built evaluation carries the strongest evidence of inter-rater, intra-rater, and test-retest reliabilities, test-validity, and responsiveness to change for bimanual tasks in hemiparetic CP children within this age range. Sensitivity to change and excellent clinimetric properties have been established in multiple pediatric hemiparetic CP clinical trials. Trained therapists have successfully executed >100 AHA measurements in previous trials with no limitations and robust data.