In the present study a sequential tapping task was used to compare the planning and execution of finger tapping sequences in children with motor coordination problems (clumsy children) and control children. Fifteen children with significant movement problems were compared to 15 control children matched on age, sex, and Verbal IQ. The clumsy children took significantly longer to initiate the movement sequence (i.e., reaction time). During the execution of the sequence, the clumsy children left their finger on the tap plate for significantly longer for each tap than the control children. No significant differences were found between the groups for the time taken between the taps, or mean average force. Past research has indicated that the source of timing problems in clumsy children may lie in a central timing mechanism possibly the cerebellum, whereas the evidence from the present study indicates an impairment of the peripheral processes may be a more important contributor to timing deficits in clumsy children. (JINS, 1999, 5, 320–329.)

A meta-analysis was conducted to identify information processing factors that characterise children with Developmental Coordination Disorder (DCD). A total of 50 studies yielded 374 effect sizes based on 983 DCD and 987 control children. A mild generalised performance deficit was indicated, since motor-impaired children were inferior on almost all measures of information processing. There were, however, several areas where their deficiencies were more pronounced. The greatest deficiency was in visual-spatial processing. This was evident regardless of whether or not the tasks involved a motor component. Most other deficiencies were in the small-to-moderate range and included kinaesthetic and cross-modal processing. The findings support the notion that perceptual problems, particularly in the visual modality, are associated with difficulties in motor coordination.

In previous papers (Sims, Henderson, Hulme, & Morton, 1996a; Sims, Henderson, Morton, & Hulme, 1996b) we have found that the motor skills of clumsy children are capable of significant improvement following relatively brief interventions. Most remarkably, this included a 10-minute intervention while testing the kinaesthetic acuity of the children using a staircase method (Pest). In this paper, we show that Pest testing improves the kinaesthetic acuity of normal children as well. We analyse the available data on the development and improvement of motor skills and kinaesthetic acuity and derive a causal model for the underlying skills. We show that at least three independent cognitive/biological components are required to account for the data. These three components are affected differently by the various interventions that have been tried. We deduce that improvement on a general test of motor impairment can be found as a result of training in kinaesthetic acuity or through other, independent factors.