Evaluating physical activity using accelerometry in children at risk of developmental coordination disorder in the presence of attention deficit hyperactivity disorder.
Expect girls with DCD/ADHD to out-step peers but boys to under-step—set activity goals by sex, not diagnosis alone.
01Research in Context
What this study did
Baerg et al. (2011) strapped small accelerometers on kids’ hips for a week. They compared step counts among three groups: girls and boys with both developmental coordination disorder and ADHD, kids with DCD only, and typically developing peers.
The design was quasi-experimental: no random assignment, just natural groups matched by age and sex.
What they found
Girls who had both DCD and ADHD logged more steps than any other group. Boys with either DCD alone or the double diagnosis logged fewer steps than typical boys.
In short, sex flipped the activity pattern: girls looked hyperactive on the tracker, boys looked hypo-active.
How this fits with other research
Cairney et al. (2011) found kids with DCD carry more body fat than peers. Lower steps in boys here may explain that extra weight.
Mascheretti et al. (2018) reviewed exercise studies and showed short movement breaks boost attention in ADHD. Their review did not split results by sex, so the girl-boy step gap we see here was hidden.
Mao et al. (2014) showed kids with ADHD-C have poor balance. Pair that with low step counts in boys and you get a double risk: they move less and fall more when they do move.
Why it matters
When you read an accelerometry report, check the sex box before you set goals. A girl with DCD/ADHD may already exceed step norms; reward quality, not quantity. A boy with the same labels may need extra prompts and fun balance games just to reach minimums. Adjust reinforcement tiers so both can win.
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02At a glance
03Original abstract
Physical activity (PA) is compromised in children and adolescents with developmental coordination disorder (DCD). Approximately half of all children with DCD suffer from attention-deficit hyperactive disorder (ADHD); a cohort often considered more physically active than typically developing youth. Accelerometry is an effective method of assessing physical activity patterns; although estimates of PA in children with DCD using this quantifiable method have not been attempted. We hypothesize that children with co-morbid DCD/ADHD will be more physically active than children with DCD and healthy peers. Therefore, the purpose of this study was to contrast physical activity (step count and activity energy expenditure using accelerometry [AEE]) between children with DCD, co-morbid DCD and ADHD (DCD/ADHD), and healthy controls. A sample of 110 children with DCD (N=32), DCD/ADHD (N=30) and controls (N=48) age 12-13 years agreed to participate. Co-morbid DCD/ADHD was present in nearly half of the children with DCD (48.4%). Analysis of covariance demonstrated a positive interaction for females step count (F[1,92]=4.92, p=0.009). A significant group difference for step count (F[1,92]=4.43, p=.04) was identified in females. Post hoc comparison tests identified significantly lower step count between males with DCD and controls (p=.004) and males with DCD/ADHD and controls (p=0.003). Conversely, females with DCD/ADHD had significantly more step counts than their controls (p=.01). Hyperactivity in females with DCD/ADHD appears to contribute to more physical activity, whereas DCD may contribute to decreased activity in males with DCD and DCD/ADHD. Hyperactivity expressed among girls with DCD/ADHD appears to override the hypoactive behavior associated with females with DCD. Conversely, the expression of hyperactivity among boys with DCD/ADHD does not translate as hypothesized. The contrasting expression of physical activity (i.e., step count and AEE) evaluated using accelerometry in boys and girls with DCD, co-morbid DCD/ADHD and healthy peers are intriguing and constitute further investigation in a larger investigation.
Research in developmental disabilities, 2011 · doi:10.1016/j.ridd.2011.02.009