Frequency of anticipatory trunk muscle onsets in children with and without developmental coordination disorder.

This study used electromyography to compare the frequency of anticipatory postural adjustments for three bilateral trunk muscles and unilateral tibialis anterior muscle between children with and without developmental coordination disorder (DCD; n = 22, ages 7 to 14 years) during three tasks (kicking a ball, stepping onto a step, standing on one foot). Between-group comparisons demonstrated significantly less frequent anticipatory activation of ipsilateral tibialis anterior, ipsilateral transversus abdominis/internal oblique, and bilateral external oblique muscles in children with DCD. Odds ratios indicated that children with DCD utilized anticipatory contractions of these muscles one half to one quarter as often as the typically developing children did, while performing the same tasks. These results suggest that the movement difficulties experienced by children with DCD may be associated with less frequent anticipatory adjustments. For these children, inconsistent preparatory activation may contribute to postural control difficulties, excessive movement variability and poor movement quality.