Children with hemiplegic or unilateral cerebral palsy (uCP) have a preference to use only one hand, and if early intervention does not occur, children often avoid or never learn to use their paretic or impaired hand. Constraint-Induced Movement Therapy (CIMT) is an evidence-based intervention where a child wears a cast on their dominant arm and therapists deliver intensive therapy to the paretic hand to improve the strength and skills of that hand. The goal of CIMT is to generate unimanual mass practice of skills in therapy which can be transferred to bimanual skills in daily life. Few studies have investigated objective measures of bimanual tasks occurring in daily life following therapy. This thesis set out to use accelerometry data to objectively quantify hand use for children with uCP before, during, and after CIMT and to compare it to typically developing (TD) children. Four children with uCP (age range: 6-8) and five TD children (age range: 2-9) were enrolled in this study. Children in the uCP cohort wore accelerometers on each wrist during three data collection periods; before, during, and six to eight weeks after CIMT and functional tests occurred before and six to eight weeks after CIMT. The TD cohort also wore the wrist accelerometers during three data collection periods temporally spaced with the uCP cohort, however no interventions occurred. Results demonstrated that before CIMT children in the uCP cohort moved their paretic hand much less than the TD cohort, but compensated by using their non-paretic hand at higher magnitude percentages than the TD cohort. Accelerometer data also suggested that although children improved the frequency of use of their paretic hand compared to their non-paretic hand (use ratio) and magnitude ratio during therapy these metrics fell back to baseline values six to eight weeks following therapy, suggesting the benefits of the therapy were not sustained. Functionally the uCP cohort improvement on clinical outcome measures for their paretic hand; box & blocks increased on average 4.4 blocks moved in 60 seconds, grip strength increased by 6 lbs, 3-point pinch increased by 3.1 lbs, lateral grasp increased by 1 lb, and children rated themselves as reaching their goals on average 4.4 points higher per goal (measured by the Canadian Occupational Performance Measure). The clinical results indicated that children may improve their ability to perform unimanual tasks following CIMT, however accelerometry data demonstrated that these gains do not transfer into increased bimanual hand use outside of the clinic. We recommend that a Remind-To-Move protocol, which has been shown to improve bimanual skills, be implemented following CIMT. Furthermore, through the use of surveys and focus groups this research provided positive perceptions from both families and clinicians for the incorporation of accelerometers into clinical practice. These results suggest that accelerometers can be used to measure movement in TD children and children with uCP outside of the clinic and that post CIMT follow-up interventions may be necessary to translate clinical gains into bimanual daily activities.