A new tool for assessing head movements and postural sway in children

Current methods of measuring gross motor abilities in children involve either high-cost specialist apparatus that is unsuitable for use in schools, or low-cost but nonoptimal observational measures. We describe the development of a low-cost system that is capable of providing high-quality objective data for the measurement of head movements and postural sway. This system is based on off-the-shelf components available for the Nintendo Wii: (1) The infrared cameras in a pair of WiiMotes are used to track head movements by resolving the position of infrared-emitting diodes in three dimensions, and (2) center-of-pressure data are captured using the WiiFit Balance board. This allows the assessment of children in school settings, and thus provides a mechanism for identifying children with neurological problems affecting posture. In order to test the utility of the system, we installed the apparatus in two schools to determine whether we could collect meaningful data on hundreds of children in a short time period. The system was successfully deployed in each school over a week, and data were collected on all of the children within the school buildings at the time of testing (N = 269). The data showed reliable effects of age and viewing condition, as predicted from previous small-scale studies that had used specialist apparatus to measure childhood posture. Thus, our system has the potential to allow screening of children for gross postural deficits in a manner that has never previously been possible. It follows that our system opens up the possibility of conducting large-scale behavioral studies concerning the development of posture.