DCD is a discrete motor disorder under the broader
heading of neurodevelopmental disorders affecting
approximately 6% of school-aged children, with boys at
greater risk than girls (DSM-5) (American Psychiatric
Association, 2013). According to the DSM-5, individuals
are diagnosed with DCD when exhibiting (1)
acquisition and execution of motor skills below what
would be expected at a given chronological age and
opportunity for skill learning and use; (2) motor skills
deficits significantly interfering with activities of daily
living (e.g., self-care and self-maintenance) appropriate
to the chronological age, impacting school productivity,
leisure, and play; (3) early development onset of symptoms;
(4) motor skills deficits that cannot be explained
by intellectual disability, visual impairment and not
attributable to a neurological condition (e.g., cerebral
palsy, muscular dystrophy, or a degenerative disorder).
Clinical studies have shown that DCD often cooccurs
with other neurodevelopmental disorders (e.g.,
Attention Deficit Hyperactivity Disorder, Autistic
Spectrum Disorder, Specific Language Impairment,
reading disorders) in 30% 50% of the cases (Gomez &
Sirigu, 2015).
Children with DCD show a wide variety of
perceptual-motor problems, difficulties with postural
control, deficits in motor prediction, visuo-spatial deficits,
and difficulties in motor learning, which cause
functional difficulties (e.g., dressing, handwriting, using
utensils, running, riding a bicycle, catching balls, and
playing sports). These difficulties contribute to secondary
long-term health consequences, including reduced
engagement in physical activity and social activities,
low fitness, and an increased risk of low self-esteem,
anxiety, and depression. The motor difficulties seen in
50% 70% of children with DCD persist into adolescence
and adulthood impacting motor tasks, such as
learning to drive a car or activities requiring high levels
of executive functioning (APA, 2013).
The underlying aetiology of the movement difficulties
associated with DCD is thought to be multifactorial as
no single cause has been identified, but etiological factors
of DCD suggest interplay of environmental (e.g.,
socioeconomic and cross-cultural influence, natal and
perinatal risk factors), and genetic factors, as well as
neuropsychological deficits such as efference copy
impairment and lack of sensory feedback to estimate
actual body states (Gomez & Sirigu, 2015). To date,
there is no consistent picture on a neural signature for
DCD; however, cerebellum, basal ganglia, parietal lobe,
and parts of the frontal lobe (medial orbitofrontal cortex
and dorsolateral prefrontal cortex) could constitute a
good signature of DCD (Biotteau et al., 2016).
Recently, gray matter volume reductions in premotor
frontal regions were identified as being reflective of the
level of motor proficiency (Reynolds et al., 2017).
Intervention strategies for children with DCD can be
categorized as (1) traditional: a combination of a variety
of sensory integrative, gross motor, fine motor, and
perceptual-motor activities (e.g., aquatic therapy); (2)
process-orientated: specifically designed kinaesthetic
tasks; or (3) task-orientated strategies (including a cognitive
component): practicing real life activities with
the intention of acquiring skill (e.g., table tennis, treadmill
training, Wii Fit, balance, taekwondo). Evidence
from a recent meta-analysis (Lucas et al., 2016) indicates
that task-orientated approaches are most effective
for improving gross motor outcomes compared to other
therapy approaches, such as traditional, processorientated,
or psychological.
