Locomoting through apertures of different width: a study of children with cerebral palsy.

Whether children with cerebral palsy (CP) differ from non-handicapped (NH) children was studied, using body-scaled information about the passability of a doorway-like opening. There were 55 children of whom 23 were NH and 32 had CP, the latter consisting of 12 who could stand and walk unaided (CP-Walk) and 20 confined to a wheelchair (CP-Wheel). All groups were divided into two age ranges (5-8 and 9-13 year) and were tested on two occasions separated by an interval of 12 months. On both occasions, testing involved three consecutive tasks: making perceptual (pre)judgments about the passability of an opening varying in width, actually attempting to locomote through the openings (performance), and another round of (post)judgments. Judgments and performance were expressed in terms of absolute and relative outcomes, the latter differing from the former in accounting for differences in body width relative to aperture width. There were two main findings. Firstly, the younger CP-Walk children were the least able to employ body-scaled information in judging aperture width and the older CP-Wheel and NH the most able. Secondly, when performances in passing through the openings were adjusted for differences in body width, all groups had similar outcomes. This findings lends credence to the notion that when action is used in the service of perception, this is beneficial for the visual-spatial abilities of both NH and CP children. The study concludes by pointing out future directions in this type of research as well as some of the clinical implications of the findings.