Observational skills assessment score: reliability in measuring amount and quality of use of the affected hand in unilateral cerebral palsy.

Background The Observational Skills Assessment Score (OSAS) measures amount and quality of use of the affected hand in children with unilateral Cerebral Palsy (CP) in bimanual activities and could therefore be a valuable addition to existing assessment tools. The OSAS consists of tasks that are age appropriate and require use of the affected hand.