Aim: To investigate the characteristics of children with DCD with different severity of motor ability and compare motor progression over time.
Introduction: Children with DCD have difficulty in the development of motor coordination and learning new motor skills. Empirical and professional evidence suggests that they differ from typically developing children, but also suggest that they are heterogeneous in nature. DCD commonly overlaps with other developmental disorders. Studies have used different cut-off points for motor impairment and yet little is known whether children’s motor progression differs for these different cut-offs or the impact on participation in physical activity (PA).
Method: An ecological mixed methods study design was used. Children had detailed profiles compiled of their individual characteristics and context. DSM-5 criteria were applied to identify children with and without DCD. Repeated motor measurements over 2 years measured motor stability or change. A case study approach identified a subset of children to interview about their experiences of participation in PA. Data analysis considered group comparison and individual motor progression through a dynamical systems lens.
Results: Children were categorized according to motor ability: ≤5th percentile, 6-16th percentile and ≥25th percentile on MABC2. Children in the lowest motor ability group had distinct characteristics. They had significant differences between their motor performance and the other groups, both at baseline and over time. It was characterized by stable, persistent and poor motor performance, while the other two groups were more variable over time.
Conclusion: Children ≤5th percentile of MABC2 appeared to have special characteristics in motor and non-motor domains. These were less variable and different to both typically developing children and to children with milder motor impairment. The results point the way to differential intervention according to the nature and severity of the characteristics in DCD in both the motor and non-motor domains.
