AbstractImportanceConstraint Induced Movement Therapy (CIMT) is a common treatment for children with unilateral cerebral palsy (CP). While clinic-based assessments have demonstrated improvements in arm function after CIMT, quantifying if these changes are translated and sustained outside of a clinic setting remains unclear.ObjectiveAccelerometers were used to quantify arm movement for children with CP one week before, during, and 4+ weeks after CIMT and compared to typically-developing (TD) peers.DesignObservational during CIMTSettingClinical assessments and treatment occurred in a tertiary hospital and accelerometry data were collected in the communityParticipants7 children with CP (5m/2f, 7.4 ± 1.2 yrs) and 7 TD peers (2m/5f, 7.0 ± 2.3 yrs)Intervention30-hour CIMT protocolOutcomes and MeasuresThe use ratio, magnitude ratio, and bilateral magnitude were calculated from the accelerometry data. Clinical measures were evaluated before and after CIMT and surveys were used to assess the feasibility of using accelerometers.ResultsBefore CIMT, children with CP used their paretic arm less than their TD peers. During therapy, their frequency and magnitude of paretic arm use increased in the clinic and in daily life. After therapy, although clinical scores improved, children reverted to baseline accelerometry values. Additionally, children and parents in both cohorts had positive perceptions of wearing accelerometers.Conclusions and RelevanceThe lack of sustained improved accelerometry metrics following CIMT suggest therapy gains did not translate to increased movement outside the clinic. Additional therapy may be needed to help the transfer of skills to the community setting.What this Article AddsThis study compares the movement of children with CP undergoing CIMT in the community setting with their typically developing peers. Additional interventions may be needed in combination with or following CIMT to sustain the benefits of the therapy outside of the clinic.