Comparison of balance performance between boys with and without developmental coordination disorder

Abstract

The purpose of the present study was to investigate the performance of 6 to 13 year old boys with and without Developmental Coordination Disorder (DCD) on two balance tasks: balance space and quiet standing. The participants were 40 boys, assigned to either a control or an experimental group, based on initial screening by teachers with the Motor Behavior Checklist, and subsequent testing conducted at Lakehead University School of Kinesiology Motor Development Clinic using the Movement ABC (MABC). Final group assignment was based on the MABC Total Impairment Score and Total Balance Score. Boys were tested in a subsequent session in 20 second trials using an AMTI force plate with the sampling frequency set at 100 Hz, gain at 4000x, 5x, and electronic filter at 10.5 Hz using the CAS stability Program to measure the following dependent measures: anterior-posterior sway, lateral sway, path length and area of sway. The study incorporated a 2 (age) x 2 (condition) completely randomized factorial design. The data analysis incorporated MANOVA, factorial ANOVA, planned comparisons and Pearson correlations, with the significance level at alpha level p< .05. The results of the study indicated that boys" without DCD and balance difficulties were more effective in the balance space task than boys with DCD and balance difficulties. There was no difference between the groups in the quiet standing tasks. Developmentally, older boys performed much better than the younger boys. A significant interaction effect based on balance space indicated that the older boys from the control group perceived their tolerance region significantly better than any other group (F (4,32) = 3.27, E < .05). It was postulated that: older boys with DCD exhibited anticipatory postural behavior similar to those of boys with no DCD who were 2 to 3 years younger, and that this gap in balance performance between boys with and without DCD increased with age. Further study of a longitudinal nature is required to confirm this hypothesis. Although the balance space task proved to be more sensitive to differences in balance performance, participants exhibited a similar pattern of behavior in both tasks. More skilled balancers scored high on balance space tasks and low on quiet standing tasks, while the reverse behavior was evident in the performance of less skilled balancers. It appears that the quality of feedforward balance responses relates to the quality of feedback based mechanisms as control children who experienced balance difficulties related to voluntary balance mechanisms also experienced difficulties with involuntary balance control. In terms of balance control and vision, children with DCD performed significantly poorer than the control group with eyes open but not with eyes closed. It was postulated that the absence of visual input may be a facilitating factor for boys who cannot effectively respond to a multisensory environment Although further study is needed, it was concluded that the balance space task is most effective at showing condition, developmental and interaction effects, whereas the quiet standing task is more sensitive to balance control differences due to age. It was recommended that for future studies both tasks be incorporated, so that the relationship between the postural mechanisms they represent can be studied further.