Using accelerometry for measurement of motor behavior in children: Relationship of real-world movement to standardized evaluation

Background: When detected, children with asymmetrical motor impairment are referred for therapeutic interventions to maximize the child's ability to reach their health and developmental potential. Referal is dependent on standardized evaluation, which rarely examines upper extremity (UE) function within the context of real-world activity. Accelerometry provides an efficient method to objectively measure movement in children. The purpose of this study was to compare accelerometry to clinical assessment, specifically the Melbourne Assessment of Unilateral Upper Limb Function-2 (MA-2). Methods: A total of 52 children between 1–17 years of age with asymmetrical motor deficits and age matched controls participated in this study. Participants wore bilateral accelerometers for 4 x 25 h. The use ratio (UR) and mono-arm use index (MAUI) were calculated to quantify asymmetrical impairment. The Melbourne Assessment of Unilateral Upper Limb Function-2 (MA-2) was administered and compared to accelerometry variables. Results: The UR and MAUI were significantly different in children with and without deficits. The MAUI was significantly correlated with all domains of the MA-2: accuracy (r = 0.44, p = 0.026); fluency (r = 0.52, p = 0.006); dexterity (r = 0.53, p = 0.005); and range of motion (r = 0.49, p = 0.011). Conclusions: Our findings suggest a relationship between real-world movement and clinical evaluation.