Developmental Coordination Disorder Group Research Articles

Corticospinal excitability during motor imagery is reduced in young adults with developmental coordination disorder

While a compelling body of behavioral research suggests that individuals with developmental coordination disorder (DCD) experience difficulties engaging motor imagery (MI), very little is known about the neural correlates of this deficit. Since corticospinal excitability is a predictor of MI proficiency in healthy adults, we reasoned that decreased MI efficiency in DCD may be paralleled by atypical primary motor cortex (PMC) activity. Participants were 29 young adults aged 18- 36 years: 8 with DCD (DCD) and 21 controls. Six participants with DCD and 15 controls showed behavioral profiles consistent with the use of a MI strategy (MI users) while performing a novel adaptation of the classic hand laterality task (HLT). Single-pulse transcranial magnetic stimulation (TMS) was administered to the hand node of the left PMC (hPMC) at 50ms, 400ms or 650ms post stimulus presentation during the HLT. Motor-evoked potentials (MEPs) were recorded from the right first dorsal interosseous (FDI) via electromyography. As predicted, MI users with DCD were significantly less efficient than MI using controls, shown by poorer performance on the HLT. Importantly, unlike healthy controls, no evidence of enhanced hPMC activity during MI was detected in our DCD group. Our data are consistent with the view that inefficient MI in DCD may be subserved by decreased hPMC activity. These findings are an important step towards clarifying the neuro-cognitive correlates of poor MI ability and motor skill in individuals with DCD.

Development of motor imagery ability in children with developmental coordination disorder - Agoal-directed pointing task.

Children with developmental coordination disorder (DCD) have difficulties with the predictive control of movements. This was shown in studies that target motor imagery and motor planning, and appears to become particularly evident with increases in task complexity. In this study, we used a complex mental chronometry paradigm to examine the development of motor imagery ability in children with DCD, using a longitudinal design. Thirty children were included in the DCD group (aged 6-11years) and age- and gender-matched to 30 controls. The DCD group had a Movement Assessment Battery for Children-2 score ≤16th percentile and the control group ≥25th percentile. Results of this study showed that children with DCD indeed had a significantly lower correlation between executed and imagined movements. Importantly, the increase in the correlation and linear fit during subsequent measurements was comparable for the DCD and control group. Together, these findings suggest a delayed developmental onset of motor imagery ability in DCD, but a similar rate of development over time compared to the control group. Based on these results, it seems likely that explicit motor imagery instructions can be used to improve predictive control in children with DCD.

Emotional and behavioural problems in children with Developmental Coordination Disorder: Exploring parent and teacher reports

BackgroundAlthough characterised by motor impairments, children with Developmental Coordination Disorder (DCD) also show high rates of psychopathology (anxiety, depression, low self-esteem). Such findings have led to calls for the screening of mental health problems in this group. AimsTo investigate patterns and profiles of emotional and behavioural problems in children with and without DCD, using the Strengths and Difficulties Questionnaire (SDQ). Methods and proceduresTeachers and parents completed SDQs for 30 children with DCD (7–10 years). Teacher ratings on the SDQ were also obtained from two typically-developing (TD) groups: 35 children matched for chronological age, and 29 younger children (4–7 years) matched by motor ability. Outcomes and resultsGroup and individual analyses compared parent and teacher SDQ scores for children with DCD. Teacher reports showed that children with DCD displayed higher rates of emotional and behavioural problems (overall, and on each subscale of the SDQ) relative to their TD peers. No differences were observed between the two TD groups. Inspection of individual data points highlighted variability in the SDQ scores of the DCD group (across both teacher and parent ratings), with suggestions of elevated hyperactivity but comparably lower levels of conduct problems across this sample. Modest agreement was found between teacher and parent ratings of children with DCD on the SDQ. Conclusions and implicationsThere is a need to monitor levels of emotional and behavioural problems in children with DCD, from multiple informants.

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When an object appears unexpectedly: foot placement during obstacle circumvention in children and adults with Developmental Coordination Disorder.

Adjustments to locomotion to avoid an obstacle require a change to the usual pattern of foot placement, i.e. changes to step length and/or step width. Previous studies have demonstrated a difficulty in individuals with Developmental Coordination Disorder (DCD) in controlling stability while both stepping over and while circumventing an obstacle. In a previous study, we have considered the way in which individuals with DCD prepare for the possibility of an obstacle appearing (Wilmut and Barnett in Exp Brain Res 235:1531-1340, 2017). Using a parallel data set from this same task on the same individuals, the aim of the current study was to investigate the exact nature of changes in foot placement during obstacle avoidance, as this was not clear from previous work. Children and adults aged from 7 to 34years of age took part in the study. Forty-four met the criteria for a diagnosis of DCD and there were 44 typically developing (TD) age and gender-matched controls. Participants walked at a comfortable pace down an 11m walkway; on 6 out of 36 trials a 'gate' closed across their pathway which required circumvention. These 6 'gate close' trials were analysed for this study. The number and magnitude of step length and step width adjustments were similar across the DCD and TD groups, however, the younger children (7-11years) made a greater number of early adjustments compared to the older children and adults (12-34years of age). In contrast the adults made a greater number of adjustments later in the movement compared to the children. In terms of foot placement adjustments a clear preference was seen across all participants to use adjustments which resulted in reducing step length, stepping away from the obstacle and a combination of these. Apart from subtle differences, the individuals with DCD make step placements to circumvent an obstacle in line with their peers. It is suggested that the choice of foot placement strategy in individuals with DCD, although in line with their peers, may not be optimal for their level of motor ability.

Tactile localization performance in children with developmental coordination disorder (DCD) corresponds to their motor skill and not their cognitive ability

When localizing touches to the hands, typically developing children and adults show a “crossed hands effect” whereby identifying which hand received a tactile stimulus is less accurate when the hands are crossed than uncrossed. This demonstrates the use of an external frame of reference for locating touches to one’s own body. Given that studies indicate that developmental vision plays a role in the emergence of external representations of touch, and reliance on vision for representing the body during action is atypical in developmental coordination disorder (DCD), we investigated external spatial representations of touch in children with DCD using the “crossed hands effect”. Nineteen children with DCD aged 7–11years completed a tactile localization task in which posture (uncrossed, crossed) and view (hands seen, unseen) were varied systematically. Their performance was compared to that of 35 typically developing controls (19 of a similar age and cognitive ability, and 16 of a younger age but similar fine motor ability). Like controls, the DCD group exhibited a crossed hands effect, whilst their overall tactile localization performance was weaker than their peers of similar age and cognitive ability, but in line with younger controls of similar motor ability. For children with movement difficulties, these findings indicate tactile localization impairments in relation to age expectations, but apparently typical use of an external reference frame for localizing touch.

Children With Developmental Coordination Disorder.

This study tested the effect of task-specific training of a perceptual ability for children with Developmental Coordination Disorder (DCD) compared to control children. A manual matching task (target location and pointing task) was used, which required the children to locate target pins either visually (seen target) or proprioceptively (felt target), while matching to the located target was always carried out without vision. Thirty-one children (11-12 years) were selected based on teacher statements regarding everyday motor skill performance, the DSM-IV criteria, and the Movement ABC test. Based on this, 10 children with obvious motor problems were placed in the DCD group (Trg-DCD), 9 children with no identified motor problems were placed in a training group (Trg-N), and 12 children also with no identified motor problems were placed in a control group. All the children were tested pre and post to training on a manual matching task. In the pretest, the children in the DCD group were significantly inferior to the control groups in the proprioceptive condition with both the preferred and nonpreferred hands. In the posttest, after the training periode was completed, the DCD subjects showed significant improvement in the proprioceptive condition for both preferred and nonpreferred hands. For the other groups, no significant training effects were observed across the training period. It is concluded that children in the DCD group may benefit from specific training of perceptual abilities, because they have motor control resources not exploited due to a lack of relevant experience.

Gait symmetry in individuals with and without Developmental Coordination Disorder

BackgroundSymmetry between the left and right side of the body during locomotion is key in a coordinated gait cycle and is also thought to be important in terms of efficiency. Although previous studies have identified aspects of the gait cycle which are atypical in children and adults with Developmental Coordination Disorder (DCD), studies have not considered whether this could be explained by asymmetrical gait. Method and procedureThe current study included 62 participants with and 62 without DCD (aged 7–34 years). Participants were asked to walk continuously for 1min up and down a walkway while movement was captured using an optical tracking system. Measures of step length and step time were taken for both the right and the left leg and symmetry ratios were calculated. ResultsThe DCD group showed significantly higher symmetry ratios for both measures compared to the typically developing (TD) group, with approximately a third of DCD participants falling outside the normative range for symmetry. Furthermore, a relationship was found between movement variability and degree of asymmetry. ConclusionsThese findings demonstrate an asymmetry in the gait of individuals with DCD which, despite improving with age, does not reach the same level as that shown by TD individuals.

Cognitive Control of Saccadic Eye Movements in Children with Developmental Coordination Disorder.

The ability to use advance information to prepare and execute a movement requires cognitive control of behaviour (e.g., anticipation and inhibition). Our aim was to explore the integrity of saccadic eye movement control in developmental coordination disorder (DCD) and typically developing (TD) children (8–12 years) and assess how these children plan and inhibit saccadic responses, the principal mechanisms within visual attention control. Eye movements and touch responses were measured (separately and concurrently) in Cued and Non-Cued conditions. We found that children with DCD had similar saccade kinematics to the TD group during saccade initiation. Advance information decreased hand movement duration in both groups during Cued trials, but decrements in accuracy were significantly worse in the DCD group. In addition, children with DCD exhibited greater inhibitory errors and inaccurate fixation during the Cued trials. Thus, children with DCD were reasonably proficient in executing saccades during reflexive (Non-Cued) conditions, but showed deficits in more complex control processes involving prediction and inhibition. These findings have implications for our understanding of motor control in children with DCD.

Coupling of online control and inhibitory systems in children with atypical motor development: A growth curve modelling study

IntroductionPrevious research indicates that children with Developmental Coordination Disorder (DCD) show deficits performing online corrections, an issue exacerbated by adding inhibitory constraints; however, cross-sectional data suggests that these deficits may reduce with age. Using a longitudinal design, the aim of the study presented here was to model the coupling that occurs between inhibitory systems and (predictive) online control in typically developing children (TDC) and in those with Developmental Coordination Disorder (DCD) over an extended period of time, using a framework of interactive specialization. We predicted that TDC would show a non-linear growth pattern, consistent with re-organisation in the coupling during the middle childhood period, while DCD would display a developmental lag. MethodA group of 196 children (111 girls and 85 boys) aged between 6 and 12years participated in the study. Children were classified as DCD according to research criteria. Using a cohort sequential design, both TDC and DCD groups were divided into age cohorts. Predictive (online) control was defined operationally by performance on a Double-Jump Reaching Task (DJRT), which was assessed at 6-month intervals over two years (5 time points in total). Inhibitory control was examined using an anti-jump condition of the DJRT paradigm whereby children were instructed to touch a target location in the hemispace opposite a cued location. ResultsFor the TDC group, model comparison using growth curve analysis revealed that a quadratic trend was the most appropriate fit with evidence of rapid improvement in anti-reach performance up until middle childhood (around 8–9years of age), followed by a more gradual rate of improvement into late childhood and early adolescence. This pattern was evident on both chronometric and kinematic measures. In contrast, for children with DCD, a linear function provided the best to fit on the key metrics, with a slower rate of improvement than controls. ConclusionWe conclude that children with DCD require a more extended period of development to effectively couple online motor control and executive systems when completing anti-reach movements, whereas TDC show rapid improvement in early and middle childhood. These group differences in growth curves are likely to reflect a maturational lag in the development of motor-cognitive networks in children with DCD.

Adaptations to walking on an uneven terrain for individuals with and without Developmental Coordination Disorder

Given the importance of walking in everyday life, understanding why this is challenging for some populations is particularly important. Studies focusing on gait patterns of individuals with Developmental Coordination Disorder (DCD) have shown that whilst increased variability is characteristic of walking patterns for this group, differences in spatio-temporal gait variables seem only to arise when task demands increase. However, these differences occur under rather artificial conditions, for example using a treadmill. The aim of this study, therefore was to examine the step characteristics of individuals with and without DCD whilst walking along an irregular terrain. Thirty-five individuals with DCD aged 8–32years and 35 age and gender-matched controls participated in this study. Participants were divided into 3 age groups; 8–12years (n=12), 13–17years (n=12) and 18–32years (n=11). Participants walked up and down a 6m walkway for two minutes on two terrains: level and irregular. VICON 3D motion analysis was used to extract measures of foot placement, velocity and angle of the head and trunk. Results showed that both groups adapted their gait to negotiate the irregular terrain, but the DCD group was more affected than their TD peers; walking significantly slower with shorter, wider steps and inclining their head more towards the ground. This suggests an adaptive approach used by individuals with DCD to preserve stability and increase visual sampling whilst negotiating an irregular terrain.

Neural changes associated to procedural learning and automatization process in Developmental Coordination Disorder and/or Developmental Dyslexia.

Recent theories hypothesize that procedural learning may support the frequent overlap between neurodevelopmental disorders. The neural circuitry supporting procedural learning includes, among others, cortico-cerebellar and cortico-striatal loops. Alteration of these loops may account for the frequent comorbidity between Developmental Coordination Disorder (DCD) and Developmental Dyslexia (DD). The aim of our study was to investigate cerebral changes due to the learning and automatization of a sequence learning task in children with DD, or DCD, or both disorders. fMRI on 48 children (aged 8-12) with DD, DCD or DD+DCD was used to explore their brain activity during procedural tasks, performed either after two weeks of training or in the early stage of learning. Firstly, our results indicate that all children were able to perform the task with the same level of automaticity, but recruit different brain processes to achieve the same performance. Secondly, our fMRI results do not appear to confirm Nicolson and Fawcett's model. The neural correlates recruited for procedural learning by the DD and the comorbid groups are very close, while the DCD group presents distinct characteristics. This provide a promising direction on the neural mechanisms associated with procedural learning in neurodevelopmental disorders and for understanding comorbidity.

Parent Report and Actigraphically Defined Sleep in Children with and without Developmental Coordination Disorder; Links with Fatigue and Sleepiness

Impaired sleep is associated with negative effects on quality of life and daytime functioning. Higher rates of sleep disturbance are reported in children with various developmental disorders. However, little is known about sleep in children with developmental coordination disorder (DCD), a condition characterized by everyday movement difficulties. Previously, in a preliminary study, we found higher rates of parent-reported sleep disturbance in children with DCD compared to controls. To examine sleep in DCD using objective measures and to examine links with daytime fatigue and sleepiness. Two groups (primary and secondary school-aged) of 15 children with DCD, plus matched controls, participated. Parent-reported child sleep was assessed using the Children's Sleep Habits Questionnaire and actigraphy provided an objective measure of sleep-wake patterns over 1 week (including weekdays and weekend). Pediatric restless legs syndrome (RLS) semi-structured diagnostic interview was conducted with each child and parent to capture symptoms of RLS. Aspects of self-rated child functioning were assessed with questionnaires (Pre-sleep Arousal Scale, Pediatric Daytime Sleepiness Scale, PedsQL Multidimensional Fatigue Scale) and mothers' reported thoughts about child sleep with the Maternal Cognitions about Infant Sleep Questionnaire. The DCD groups had greater parent-reported sleep disturbance. Actigraphy results suggested that for secondary aged children with DCD their sleep quality was impaired and there were differences in the timing of sleep compared to controls (including some differences in the variation between weekday and weekend sleep times). The actigraphy of the primary age group with DCD was unremarkable compared to controls. No child in the study met the criteria for RLS. Exploratory analyses suggested that daytime fatigue, aspects of pre-sleep arousal, and daytime sleepiness were reported as greater in the DCD groups and were particularly related to objective sleep parameters in the DCD groups. Maternal thoughts about sleep did not differ between the DCD and control groups. The nature and underlying cause of sleep disturbance and how it might be linked with aspects of daytime functioning in adolescents with DCD requires further research. Meanwhile, clinical awareness of the risk of atypical sleep patterns/sleep problems in DCD is important to ensure early identification and implementation of appropriate support.

The effect of exergames on functional strength, anaerobic fitness, balance and agility in children with and without motor coordination difficulties living in low-income communities

Children with Developmental Coordination Disorder (DCD) are physically less active, preferring more sedentary behavior and are at risk of developing health problems or becoming overweight. 18 children (age 6–10years) with lower levels of motor coordination attending a primary school in a low-income community in South Africa (score on Movement Assessment Battery for Children Second edition equal to or below the 5th percentile) were selected to participate in the study and were age-matched with typically developing peers (TD). Both groups of children engaged in 20min of active Nintendo Wii Fit gaming on the balance board, twice a week for a period of five weeks. All children were tested before and after the intervention using the lower limb items of the Functional Strength Measurement, the 5×10 meter sprint test, the 5×10 meter slalom sprint test, and the Balance, Running speed and Agility subtest of the Bruininks Oseretsky Test of Motor Proficiency 2nd edition (BOT-2).After intervention, both groups of children improved in functional strength and anaerobic fitness. The magnitude of these changes was not related to participant’s motor coordination level. However, differences in change between the TD and DCD group were apparent on the motor performance tests; children with DCD seemed to benefit more in balance skills of the BOT-2, while the TD children improved more in the Running speed and Agility component of the BOT-2. Compliance to the study protocol over 5weeks was high and the effect on physical functioning was shown on standardized measures of physical performance validated for children with and without DCD.

Changes in dynamic balance control over time in children with and without Developmental Coordination Disorder

The aim of this study was to examine differences in underlying adaptations of dynamic balance in children with and without Developmental Coordination Disorder (DCD) during a Wii Fit game and to measure changes over time and after intervention.Twenty-eight children with DCD and 21 typically developing (TD) children participated in the study. Analyses of force plate variables showed that the TD group initially used a longer path length for the ski slope descent and tended toward more variation in Center of Pressure (CoP) displacement in lateral direction than the children with DCD. In contrast, the TD group showed a trend of fewer reversals per cm in both AP and lateral direction. After the nonintervention period, the TD group improved performance by decreasing the path length, while the DCD group improved by increasing the path length and by decreasing the number of reversals. After intervention, no changes were found in sway characteristics. Individual analyses within the DCD group showed that the path length per run fell more often within the 95% confidence Interval of the faultless runs. In conclusion both TD and DCD children modify the underlying kinetics of dynamic balance control, but in different ways and both lead to better performance.

Defining the neuroanatomic basis of motor coordination in children and its relationship with symptoms of attention-deficit/hyperactivity disorder.

When children have marked problems with motor coordination, they often have problems with attention and impulse control. Here, we map the neuroanatomic substrate of motor coordination in childhood and ask whether this substrate differs in the presence of concurrent symptoms of attention-deficit/hyperactivity disorder (ADHD). Participants were 226 children. All completed Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5)-based assessment of ADHD symptoms and standardized tests of motor coordination skills assessing aiming/catching, manual dexterity and balance. Symptoms of developmental coordination disorder (DCD) were determined using parental questionnaires. Using 3 Tesla magnetic resonance data, four latent neuroanatomic variables (for the cerebral cortex, cerebellum, basal ganglia and thalamus) were extracted and mapped onto each motor coordination skill using partial least squares pathway modeling. The motor coordination skill of aiming/catching was significantly linked to latent variables for both the cerebral cortex (t = 4.31, p < 0.0001) and the cerebellum (t = 2.31, p = 0.02). This effect was driven by the premotor/motor cortical regions and the superior cerebellar lobules. These links were not moderated by the severity of symptoms of inattention, hyperactivity and impulsivity. In categorical analyses, the DCD group showed atypical reduction in the volumes of these regions. However, the group with DCD alone did not differ significantly from those with DCD and co-morbid ADHD. The superior cerebellar lobules and the premotor/motor cortex emerged as pivotal neural substrates of motor coordination in children. The dimensions of these motor coordination regions did not differ significantly between those who had DCD, with or without co-morbid ADHD.

Examining the cognitive profile of children with Developmental Coordination Disorder

BackgroundWhile primarily a motor disorder, research considering the cognitive abilities in children with Developmental Coordination Disorder (DCD) is limited; even though these children often struggle academically. AimsThe present study aimed to characterise the IQ profile of children with and without DCD, and to identify whether children with DCD exhibit specific cognitive weaknesses. Methods and procedures104 children participated in the study. Fifty-two children (mean age, 9 years) with a diagnosis of DCD were matched to 52 typically-developing children by age and gender. Cognitive ability was assessed using the Wechsler Intelligence Scale for Children (WISC-IV). Outcomes and resultsChildren with DCD performed poorer than their peers on processing speed and working memory measures. Individual analyses revealed varied performance in the DCD group across all cognitive indices, despite displaying Full-Scale IQs in the typical range. Discriminant function analyses show processing speed and working memory performance predicted only 23% of between-group variability. ConclusionsChildren with DCD present with a heterogeneous cognitive profile, lending support to individual case analyses in research and when designing educational assistance plans. The motorically-demanding nature of the WISC-IV processing speed tasks raises specific concerns about using this index of the IQ assessment in this population. Research and practical implications are raised.

Revealing hot executive function in children with motor coordination problems: What’s the go?

Recent research suggests that children with Developmental Coordination Disorder (DCD) often show deficits in executive functioning (EF) and, more specifically, the ability to use inhibitory control in ‘hot’, emotionally rewarding contexts. This study optimized the assessment of sensitivity of children with DCD to emotionally significant stimuli by using easily discriminable emotional expressions in a go/no-go task. Thirty-six children (12 with DCD), aged 7–12years, completed an emotional go/no-go task in which neutral facial expressions were paired with either happy or sad ones. Each expression was used as both, a go and no-go target in different runs of the task. There were no group differences in omission errors; however, the DCD group made significantly more commission errors to happy no-go faces. The particular pattern of performance in DCD confirms earlier reports of (hot) EF deficits. Specifically, a problem of inhibitory control appears to underlie the atypical pattern of performance seen in DCD on both cold and hot EF tasks. Disrupted coupling between cognitive control and emotion processing networks, such as fronto-parietal and fronto-striatal networks, may contribute to reduced inhibitory control in DCD. The implications for a broader theoretical account of DCD are discussed, as are implications for intervention.

Overlapping Phenotypes in Autism Spectrum Disorder and Developmental Coordination Disorder: A Cross-Syndrome Comparison of Motor and Social Skills.

Motor and social difficulties are often found in children with an autism spectrum disorder (ASD) and with developmental coordination disorder (DCD), to varying degrees. This study investigated the extent of overlap of these problems in children aged 7–10 years who had a diagnosis of either ASD or DCD, compared to typically-developing controls. Children completed motor and face processing assessments. Parents completed questionnaires concerning their child’s early motor and current motor and social skills. There was considerable overlap between the ASD and DCD groups on the motor and social assessments, with both groups more impaired than controls. Furthermore, motor skill predicted social functioning for both groups. Future research should consider the relationships between core symptoms and their consequences in other domains.

Atypical speech lateralization in adults with developmental coordination disorder demonstrated using functional transcranial Doppler ultrasound.

Research using clinical populations to explore the relationship between hemispheric speech lateralization and handedness has focused on individuals with speech and language disorders, such as dyslexia or specific language impairment (SLI). Such work reveals atypical patterns of cerebral lateralization and handedness in these groups compared to controls. There are few studies that examine this relationship in people with motor coordination impairments but without speech or reading deficits, which is a surprising omission given the prevalence of theories suggesting a common neural network underlying both functions. We use an emerging imaging technique in cognitive neuroscience; functional transcranial Doppler (fTCD) ultrasound, to assess whether individuals with developmental coordination disorder (DCD) display reduced left‐hemisphere lateralization for speech production compared to control participants. Twelve adult control participants and 12 adults with DCD, but no other developmental/cognitive impairments, performed a word‐generation task whilst undergoing fTCD imaging to establish a hemispheric lateralization index for speech production. All participants also completed an electronic peg‐moving task to determine hand skill. As predicted, the DCD group showed a significantly reduced left lateralization pattern for the speech production task compared to controls. Performance on the motor skill task showed a clear preference for the dominant hand across both groups; however, the DCD group mean movement times were significantly higher for the non‐dominant hand. This is the first study of its kind to assess hand skill and speech lateralization in DCD. The results reveal a reduced leftwards asymmetry for speech and a slower motor performance. This fits alongside previous work showing atypical cerebral lateralization in DCD for other cognitive processes (e.g., executive function and short‐term memory) and thus speaks to debates on theories of the links between motor control and language production.