Does relative body fat influence the Movement ABC-2 assessment in children with and without developmental coordination disorder?

Study protocol to examine the effects of acute exercise on motor learning and brain activity in children with developmental coordination disorder (ExLe-Brain-DCD)

INTRODUCTION

Developmental coordination disorder (DCD) is one of the most prevalent pediatric chronic conditions. Without proper intervention, significant delays in motor skill performance and learning may persist until adulthood. Moderate-to-vigorous physical exercise has been proven to improve motor learning (adaptation and consolidation) in children with or without disorders. However, the effect of a short bout of physical exercise on motor adaptation and consolidation in children with DCD has not been examined. Furthermore, the role of perceptual-motor integration and attention as mediators of learning has not been examined via neuroimaging in this population.

OBJECTIVES

Therefore, the primary aims of this project will be to compare children with and without DCD to (a) examine the effect of acute exercise on motor learning (adaptation and consolidation) while performing a rotational visuo-motor adaptation task (rVMA), and (b) explore cortical activation in the dorsolateral- and ventrolateral-prefrontal cortex areas while learning the rVMA task under rest or post-exercise conditions.

METHODS

One hundred twenty children will be recruited (60 DCD, 60 controls) and within-cohort randomly assigned to either exercise (13-minute shuttle run task) or rest prior to performing the rVMA task. Adaptation and consolidation will be evaluated via two error variables and three retention tests (1h, 24h and 7 days post adaptation). Cortical activation will be registered via functional near-infrared spectroscopy (fNIRS) during the baseline, adaptation, and consolidation.

DISCUSSION

We expect to find exercise benefits on motor learning and attention so that children with DCD profiles will be closer to those of children with typical development. The results of this project will provide further evidence to: (a) better characterize children with DCD for the design of educational materials, and (b) establish acute exercise as a potential intervention to improve motor learning and attention.

Identifying Children with Developmental Coordination Disorder via Parental Questionnaires. Spanish Reference Norms for the DCDDaily-Q-ES and Correlation with the DCDQ-ES

Developmental Coordination Disorder (DCD) is one of the most prevalent neurodevelopmental disorders in school-aged children, with major consequences in psychosocial and physical health. Adequate identification of this disorder is necessary to prompt effective interventions. The aims of this study were to develop the Spanish adjusted reference norms for the DCDDaily-Q and to test the correlation and agreement between the Spanish versions of the DCDDaily-Q (DCDDaily-Q-ES) and the Developmental Coordination Disorder Questionnaire (DCDQ-ES), two reliable instruments to assess motor performance and DCD. Clinically relevant percentiles were calculated for the DCDDaily-Q-ES using a representative sample of Spanish children aged 5 to 10 years (n = 356; M = 7.3 years, SD = 1.8; boys = 50%). Pearson's correlation coefficient and intraclass correlation coefficient (ICC) were used to determine correlation and agreement between questionnaires, respectively. A moderate and significant correlation and agreement between DCDDaily-Q-ES and DCDQ-ES was found (r = 0.406; ICC = 0.381; p < 0.001). Differences in daily participation and performance were found between age groups, but not between boys and girls. Spanish age-adjusted percentiles and cutoff scores for DCDDaily-Q-ES are provided. This study offers further validation and relevant information regarding assessment of DCD and has practical implications for clinical practice and research.

Physical and Mental Health of Children with Developmental Coordination Disorder

Developmental coordination disorder (DCD) is a neurodevelopmental condition characterized by poor motor proficiency that interferes with an individual’s activities of daily living. These problems in motor coordination are prevalent despite children’s intelligence levels. Common symptoms include marked delays in achieving motor milestones and clumsiness, typically associated with poor balance, coordination, and especially handwriting skills. Currently, DCD is said to impact about 2–7% of school-age children. More importantly, DCD is considered to be one of the major health problems among school-aged children worldwide, with unique consequences to physical and mental health. Because these children and adolescents often experience difficulties participating in typical childhood activities (e.g., riding a bike), they tend to be more sedentary, more overweight/obese, at a higher risk for coronary vascular disease, and have lower cardiorespiratory and physical fitness than their typically developing peers. From another perspective, the motor difficulties have also been linked to an increased risk for mental health issues, such as higher anxiety and depression. The understanding of the health consequences associated with DCD offers practical applications for the understanding of the mechanisms and intervention protocols that can improve the consequences of this condition. In this review, I will explore such consequences and provide evidence for the implementation of interventions that focus on improving physical and mental health in this population.

Physical fitness and overweight in Israeli children with and without developmental coordination disorder: gender differences

Physical fitness and overweight among children has become paramount in the general population and more so in children with developmental coordination disorder (DCD). The purpose of the current study was to examine the association between physical fitness and overweight in a sample of Israeli children in comparison to typical children, and to examine gender differences. DCD was identified through total scores on the movement assessment battery for children 2 (MABC-2) equal to or less than the 16th percentile as well as parents' report that the child's deficits in motor skills interfered with at least two daily life activities. The sample included a group of children with DCD (n=22, M age=8.70 [SD=1.36], 16 boys [73%]) and a control group of typical children (n=47, M age=8.90 [SD=1.52], 34 boys [72%]). Measures included the strength subtest of the Bruininks-Oseretsky test of motor proficiency (BOT-2), the six minutes' walk test (6MWT) with heart rate measure, BMI and the percentage of body fat. Significant differences between DCD and typical children were found on all variables of physical fitness and weight. A two-way analysis of variance (ANOVA) analysis (group/gender) also revealed significant interactions for the percentage of body fat (F=8.51, p<.005) and BMI (F=4.50, p<.038) meaning that less fit children are more obese. The current study supports previous findings that children with DCD are less physically fit and more overweight compared to typically developing children. Moreover, in comparing between the genders, the girls in the study sample weighed more and had a significantly higher percentage of body fat than boys, it is essential to further our understanding of the relationships between obesity, physical fitness and gender among children with and without DCD.

Submaximal oxygen cost during incremental exercise in children with developmental coordination disorder

There has been minimal evidence examining the differences in submaximal aerobic power between children with and without probable developmental coordination disorder (pDCD). This is important as most activities of daily living are performed at submaximal levels. The aim of this study was to examine the oxygen cost of work (VO2) performed during an incremental exercise protocol on a cycle ergometer. Subjects with pDCD (n=63) were matched for age and gender to 63 typically developing controls (12-13 years of age) using a nested case-control design. Motor coordination was assessed using the Movement Assessment Battery for Children. Children with pDCD had significantly lower VO2 peak values relative to controls (35.0 vs. 42.9 ml/kg/min, p<0.0001). At the submaximal level, mixed effects modeling demonstrated that, after controlling for relative body fat, and VO2 peak, children with pDCD had consistently greater oxygen cost (VO2 ml/kg/min) compared to controls at any given exercise intensity (p=0.0006). A significant interaction between pDCD and workload indicated that the difference in VO2 at higher workloads is greater than that at lower workloads (p=0.0004). Children with pDCD utilize more oxygen to sustain the same submaximal workload. The implication of these findings is that children with pDCD may experience earlier fatigue than well coordinated individuals when engaging in physical activity.