Motor and gestural performance in children with autism spectrum disorders, developmental coordination disorder, and/or attention deficit hyperactivity disorder.

Motor and gestural skills of children with autism spectrum disorders (ASD), developmental coordination disorder (DCD), and/or attention deficit hyperactivity disorder (ADHD) were investigated. A total of 49 children with ASD, 46 children with DCD, 38 children with DCD+ADHD, 27 children with ADHD, and 78 typically developing control children participated. Motor skills were assessed with the Bruininks-Oseretsky Test of Motor Proficiency Short Form, and gestural skills were assessed using a test that required children to produce meaningful gestures to command and imitation. Children with ASD, DCD, and DCD+ADHD were significantly impaired on motor coordination skills; however, only children with ASD showed a generalized impairment in gestural performance. Examination of types of gestural errors revealed that children with ASD made significantly more incorrect action and orientation errors to command, and significantly more orientation and distortion errors to imitation than children with DCD, DCD+ADHD, ADHD, and typically developing control children. These findings suggest that gestural impairments displayed by the children with ASD were not solely attributable to deficits in motor coordination skills.     

Understanding performance deficits in developmental coordination disorder: a meta‐analysis of recent research

Aim Developmental coordination disorder (DCD) is a significant disorder of childhood, characterized by core difficulties in learning fine and/or gross motor skills, and the attendant psychosocial problems. The aim of the meta‐analysis presented here (the first on DCD since 1998) was to summarize trends in the literature over the past 14 years and to identify and describe the main motor control and cognitive deficits that best discriminate children with DCD from those without. Method A systematic review of the literature published between January 1997 and August 2011 was conducted. All available journal papers reporting a comparison between a group of children with DCD and a group of typically developing children on behavioural measures were included. Results One hundred and twenty‐nine studies yielded 1785 effect sizes based on a total of 2797 children with DCD and 3407 typically developing children. Across all outcome measures, a moderate to large effect size was found, suggesting a generalized performance deficit in children with DCD. The pattern of deficits suggested several areas of pronounced difficulty, including internal (forward) modelling, rhythmic coordination, executive function, gait and postural control, catching and interceptive action, and aspects of sensoriperceptual function. Interpretation The results suggest that the predictive control of action may be a fundamental disruption in DCD, along with the ability to develop stable coordination patterns. Implications for theory development and intervention are discussed.     

The effectiveness of exercise intervention on inhibitory control in children with developmental coordination disorder: Using a visuospatial attention paradigm as a model

Children with developmental coordination disorder (DCD) have been demonstrated to show a deficit of inhibitory control in volitional shifts of attention. The aim of this study was to use ecological intervention to investigate the efficacy of table-tennis training on treating both problems with attentional networks and motor disorder in children with DCD. Forty-three children aged 9–10 years old were screened using the Movement Assessment Battery for Children and divided into DCD (n = 27) and typically developing (TD, n = 16) groups. Children with DCD were then quasi-randomly assigned to either a DCD-training group who underwent a ten-week table-tennis training program with a frequency of 3 times a week or a DCD non-training group. Before and after training, the capacity of inhibitory control was examined with the endogenous Posner paradigm task for DCD and TD groups. Table-tennis training resulted in significant improvement of cognitive and motor functions for the children with DCD. The study demonstrated that exercise intervention employed within the school setting can benefit the inhibitory control and motor performance in children with DCD. However, future research efforts should continue to clarify whether the performance gains could be maintained over time.     

A dyspraxic deficit in specific language impairment and developmental coordination disorder? Evidence from hand and arm movements

The extent to which children with either specific language impairment (SLI) or developmental coordination disorder (DCD) could be considered dyspraxic was examined using three tasks involving either familiar, or unfamiliar actions. SLI is diagnosed in children who fail to develop language in the normal fashion for no apparent reason, while the DCD diagnosis is applied to a child who experiences problems with movement in the absence of other difficulties. Seventy-two children aged between 5 and 13 years participated, falling into one of four groups: (1) children with specific language impairment (SLI), (2) children with developmental coordination disorder (DCD), (3) age-matched control children, and (4) younger control children. The performance of the clinical groups resembled that of younger normally developing children. Children with SLI, DCD, and the younger controls showed significant difficulty on the task requiring the production of familiar, but not unfamiliar postures. The deficit observed in the SLI group is particularly striking because it was seen both in those with and those without recognized motor difficulties.     

Nature of motor impairments in autism spectrum disorder: A comparison with developmental coordination disorder

Introduction: Several authors have suggested the existence of motor disorders associated with developmental coordination disorder (DCD) in individuals with autism spectrum disorder (ASD). However, there are few comparative studies of psychomotor profiles that include assessments of neurological soft signs in children with ASD or DCD. We used a neuropsychomotor assessment for children with ASD from a standardized neurodevelopmental examination to understand the nature of the difficulties these children encounter. To uncover the differences and similarities in psychomotor profiles, we compared the profiles of children with ASD with those of children with DCD and focused on two recently described DCD subgroups: visuospatial–constructional (VSC) and mixed (MX).

Methods: We compared 18 children with ASD and 58 children with DCD (33 with VSC-DCD and 25 with MX-DCD) who were assessed with a battery of French-language tests (the NP-MOT) to evaluate the neuropsychomotor functions associated with visual perception and visual–spatial–motor structuring.

Results: Although there were similarities between the profiles of children with ASD and those with DCD (VSC-DCD or MX-DCD), these similarities were not associated with the predictive diagnostic markers that characterized subtypes of DCD. Instead, many variables (visuospatial–motor structuration, synkinetic movements, dynamic balance, manual dexterity, coordination, praxis, bodily spatial integration, and digital perception) differed among the three groups; the best performance was observed in the children with ASD.

Conclusion: The neuropsychomotor profiles of children with ASD and those with VSC-DCD or MX-DCD differed, and these differences are discussed. Our results highlight that impairments of ASD are specific about lateralization disturbances and support the hypothesis of proprioceptive impairment due to visual fixation problems influenced by muscular tone in relation to the subcortical and cortical structures and possible interhemispheric disorder. Thus, some neuropsychomotor functions that underpin both gestures and a set of motor skills are affected.     

Influence of methylphenidate on motor performance and attention in children with developmental coordination disorder and attention deficit hyperactive disorder

Individuals with attention deficit hyperactive disorder (ADHD) often have coexisting developmental coordination disorder (DCD). The positive therapeutic effect of methylphenidate on ADHD symptoms is well documented, but its effects on motor coordination are less studied. We assessed the influence of methylphenidate on motor performance in children with comorbid DCD and ADHD. Participants were 30 children (24 boys) aged 5.10–12.7 years diagnosed with both DCD and ADHD. Conners’ Parent Rating Scale was used to reaffirm ADHD diagnosis and the Developmental Coordination Disorder Questionnaire was used to diagnose DCD. The Movement Assessment Battery for Children-2 and the online continuous performance test were administrated to all participants twice, with and without methylphenidate. The tests were administered on two separate days in a blind design. Motor performance and attention scores were significantly better with methylphenidate than without it (p < 0.001 for improvement in the Movement Assessment Battery for Children-2 and p < 0.006 for the online continuous performance test scores).The findings suggest that methylphenidate improves both attention and motor coordination in children with coexisting DCD and ADHD. More research is needed to disentangle the causality of the improvement effect and whether improvement in motor coordination is directly affected by methylphenidate or mediated by improvement in attention.     

Postural responses to a suprapostural visual task among children with and without developmental coordination disorder

We sought to determine the effects of varying the perceptual demands of a suprapostural visual task on the postural activity of children with developmental coordination disorder (DCD), and typically developing children (TDC). Sixty-four (32 per group) children aged between 9 and 10 years participated. In a within-participants design, each child performed a signal detection task at two levels of difficulty, low (LD) and high difficulty (HD). During performance of the signal detection tasks we recorded positional variability of the head and torso using a magnetic tracking system. We found that task difficulty had a greater effect on task performance among the TDC group than among children with DCD. Overall positional variability was greater the DCD group than in the TDC group. In the TDC group, positional variability was reduced during performance of the HD task, relative to sway during performance of the LD task. In the DCD group, positional variability was greater during performance of the HD task than during performance of the LD task. In children, DCD may reduce the strength of functional integration of postural activity with the demands of suprapostural visual tasks.     

Performance of gesture in children with and without DCD: effects of sensory input modalities

This study aimed to investigate the extent to which gesture performance depends on input modality and whether gestural development patterns differ in children with and without developmental coordination disorder (DCD). Therefore, development of limb gesture was studied in 140 children--105 control children (94 males, 11 females) and in 35 children with DCD (29 males, six females) divided into three age bands: 5 to 6 years, 7 to 8 years, and 9 to 10 years. Transitive gestural skills were investigated through four input modalities: Imitation, Visual plus Tactile, Visual, and Verbal. Results indicate that limb gestural skills in normally developing children follow a progressive maturation pattern: Imitation, Visual plus Tactile, and visual routes appear to mature before the verbal route and appear to be available earlier to enable the child to perform a correct gesture. The performance of children with DCD throughout the four modalities suggested a general maturational delay. When gestures were required through the Verbal modality, there was a specific deficit in using sensory-motor information and in integrating it into a motor representation. In the Verbal modality, children with DCD performed consistently worse than their control peers and the difference in performance tended to increase rather than improve with age.     

Motor imagery and action observation for predictive control in developmental coordination disorder

In 2019, international clinical practice recommendations on the definition, diagnosis, assessment, intervention, and psychosocial aspects of developmental coordination disorder (DCD) were published. Informing our understanding of mechanisms, recent systematic reviews have shown that children with DCD have difficulties with the predictive control of movements, including aspects of motor planning, which is expressed as the internal modeling deficit hypothesis. This motor control deficit is most evident when the spatial and temporal demands of a task increase. An increasing number of empirical studies suggest that motor planning problems can be remediated through training based on one or a combination of motor imagery and action observation. In this review, we show evidence of motor planning problems in children with DCD and show that task demands or complexity affects its appearance. Implications of these findings are treatments based on motor imagery and action observation to remediate motor planning issues. The article concludes with recommendations for future research.     

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

Developmental coordination disorder (DCD) is a condition that results in an impairment of gross and/or fine motor coordination. Compromised motor coordination contributes to lower levels of physical activity, which is associated with elevated body fat. The impact of elevated body fat on motor coordination diagnostic assessments in children with DCD has not been established. The purpose of this study was to determine if relative body fat influences performance on the Movement Assessment Battery for Children, 2nd Edition (MABC-2) test items in children with and without DCD. A nested case–control, design was conducted within the Physical Health Activity Study Team longitudinal cohort study. The MABC-2 was used to assess motor coordination to categorize cases and matched controls. Relative body fat was assessed using whole body air displacement plethysmography. Relative body fat was negatively associated with the MABC-2 “balance” subcategory after adjusting for physical activity and DCD status. Relative body fat did not influence the subcategories of “manual dexterity” or “aiming and catching”. Item analysis of the three balance tasks indicated that relative body fat significantly influences both “2-board balance” and “zig-zag hopping”, but not “walking heel-toe backwards”. Children with higher levels of relative body fat do not perform as well on the MABC-2, regardless of whether the have DCD or not. Dynamic balance test items are most negatively influenced by body fat. Health practitioners and researchers should be aware that body fat can influence results when interpreting MABC-2 test scores.     

Deficits of visuospatial attention with reflexive orienting induced by eye-gazed cues in children with developmental coordination disorder in the lower extremities: An event-related potential study

The present study aims to investigate and compare the behavioral performance and event-related potentials (ERPs) measures in children with developmental coordination disorder (DCD) and typically developing (TD) children when performing the visuospatial attention task with reflexive orienting. Thirty children with DCD and 30 TD children were recruited and presented with central eye-gazed cues. The children needed to detect and respond to laterally presented reaction signals preceded by centrally presented non-predictive directional and non-directional eye-gazed cues, which directed them to attend covertly to the right or left field location, or straight ahead, via stepping on pedals with their bilateral lower limbs, while brain ERPs were concurrently recorded. The behavioral data showed that children with DCD responded slowly and exhibited a deficit in inhibitory control capacity as compared to TD children. In terms of electrophysiological characteristics, children with DCD showed distinct modulatory effects upon longer N2 and P3 latencies, smaller P3 amplitude, an elongated interval between N2 and the motor response (N2 latency-RT), and small areas on Contingent Negative Variation (CNV). The behavioral and ERP data suggest that children with DCD could have deficits in the ventral attention network and the mechanisms on the inhibitory control difficulty, when performing such a task, could be a slower response inhibitory process and stimulus classification speed, less ability in interhemispheric and cognitive-to-motor transfer speed, and less mature abilities with regard to anticipatorily executive and motor preparatory processes.     

Mathematical problems in children with developmental coordination disorder

Developmental coordination disorder (DCD) is a heterogeneous disorder, which is often co-morbid with learning disabilities. However, mathematical problems have rarely been studied in DCD. The aim of this study was to investigate the mathematical problems in children with various degrees of motor problems. Specifically, this study explored if the development of mathematical skills in children with DCD is delayed or deficient. Children with DCD performed significantly worse for number fact retrieval and procedural calculation in comparison with age-matched control children. Moreover, children with mild DCD differed significantly from children with severe DCD on both number fact retrieval and procedural calculation. In addition, we found a developmental delay of 1 year for number fact retrieval in children with mild DCD and a developmental delay of 2 years in children with severe DCD. No evidence for a mathematical deficit was found. Diagnostic implications are discussed.     

Visual–proprioceptive mapping in children with developmental coordination disorder

Developmental coordination disorder (DCD) occurs in a small but significant proportion of children who present with impaired body-eye coordination and show poor acquisition of motor skills. This study investigated the visual-proprioceptive mapping ability of children with DCD from a small selected group, with particular reference to the use of vision in matching tasks. The children with DCD in this study were significantly poorer than control children on all matching tasks. They seemed to have particular difficulty in cross-modal judgements that required the use of visual information to guide proprioceptive judgements of limb position. A distinction is drawn between tasks that can be achieved purely through sensory matching and those that require body-centred spatial judgements, suggesting that it is the latter that posits a particular difficulty for children with DCD.     

Fine motor skills and effects of methylphenidate in children with attention-deficit-hyperactivity disorder and developmental coordination disorder

The aims of this study were to investigate fine motor skills of children with both attention-deficit-hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) and those of a control group, and to examine the effects of methylphenidate on these skills. A group of 12 children with ADHD-DCD (11 males, one female; mean age 9y 8mo [SD 1y 7mo]) and 12 age- and sex-matched controls (mean age 9y 7mo [SD 1y 2 mo]) participated. The manual dexterity subtests of the Movement Assessment Battery for Children, the concise assessment method for children's handwriting, and a computerized graphomotor task were used. Results demonstrated that children with ADHD-DCD performed more poorly on the manual dexterity subtests, had poorer quality of handwriting, and drew more rapidly, more fluently, but less accurately than controls on the graphomotor task. On methylphenidate, manual dexterity and quality of handwriting improved, and strokes on the graphomotor task became less fluent but more accurate. ADHD is characterized by persistent symptoms of inattention, impulsivity, and hyperactivity, affecting 3 to 5% of school-age children. Up to 50% of children with ADHD also have motor coordination problems that are severe enough to meet criteria for DCD. In DCD, children demonstrate functional motor performance deficits not explained by the child's (chronological) age or intellect, or by other neurological or psychiatric disorders.     

Developmental coordination disorder in children with attention-deficit-hyperactivity disorder and physical therapy intervention

Although physical therapy (PT) is effective in improving motor function in children with developmental coordination disorder (DCD), insufficient data are available on the impact of this intervention in children with combined attention-deficit-hyperactivity disorder (ADHD) and DCD. This prospective study aimed to establish the prevalence of DCD among a cohort of patients with ADHD, characterize the motor impairment, identify additional comorbidities, and determine the role of PT intervention on these patients. DCD was detected in 55.2% of 96 consecutive children with ADHD (81 males, 15 females), mostly among patients with the inattentive type (64.3% compared with 11% of those with the hyperactive/impulsive type, p<0.05). Mean age was 8 years 4 months (SD 2 y). Individuals with both ADHD and DCD more often had specific learning disabilities (p=0.05) and expressive language deficits (p=0.03) than children with ADHD only. Twenty-eight patients with ADHD and DCD randomly received either intensive group PT (group A, mean age 9 y 3 mo, SD 2 y 3 mo) or no intervention (group B, mean age 9 y 3 mo, SD 2 y 2 mo). PT significantly improved motor performance (assessed by the Movement Assessment Battery for Children; p=0.001). In conclusion, DCD is common in children with ADHD, particularly of the inattentive type. Patients with both ADHD and DCD are more likely to exhibit specific learning disabilities and phonological (pronunciation) deficits. Intensive PT intervention has a marked impact on the motor performance of these children.     

A staged approach for identifying children with developmental coordination disorder from the population

The purpose of this study was to describe the motor, attention and intellectual characteristics of a population-based sample of children first screened for motor impairment and to discuss the recruitment and identification methods employed. A two stage cross-sectional, school-based survey was conducted to screen for children with motor coordination difficulties and to identify children with an existing diagnosis of attention deficit hyperactivity disorder/attention deficit disorder (ADHD/ADD). The identified children, and a random sample of typically developing children, were assessed to confirm or rule out the presence of developmental coordination disorder (DCD).Six thousand four hundred and seventy five children were invited to participate; 2943 children, with parental consent, completed the initial screening process. Two hundred eighty four children with possible motor impairment were identified. The parents of 113 children consented to a full assessment. Sixty eight children of the 113 children met diagnostic criteria for DCD, and 26 also had ADHD. Twenty eight of the 55 children who screened in with a diagnosis of ADHD were subsequently found to have DCD. The total number of children with confirmed characteristics of DCD was reduced after application of DCD diagnostic criteria. This study differs from others with regard to the additional screening for children with ADHD/ADD. The second stage assessment notably increased the number of children identified with both ADHD and DCD.     

Working memory, processing speed, and set-shifting in children with developmental coordination disorder and attention-deficit-hyperactivity disorder

It has been suggested that the high levels of comorbidity between attention-deficit-hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) may be attributed to a common underlying neurocognitive mechanism. This study assessed whether children with DCD and ADHD share deficits on tasks measuring working memory, set-shifting, and processing speed. A total of 195 children aged between 6 years 6 months and 14 years 1 month (mean 10y 4mo [SD 2y 2mo]) were included in this study. A control group (59 males, 79 females), a DCD group (12 males, six females), an ADHD-predominantly inattentive group (16 males, four females), and an ADHD-combined group (15 males, four females), were tested on three executive functioning tasks. Children with DCD were significantly slower on all tasks, supporting past evidence of a timing deficit in these children. With few exceptions, children with ADHD did not perform more poorly than control children. These findings demonstrate the importance of identifying children with motor deficits when examining tasks involving a timing component.     

Assessment of body composition using whole body air-displacement plethysmography in children with and without developmental coordination disorder

Developmental coordination disorder (DCD) is a neuro-developmental disorder characterized by poor fine and/or gross motor coordination. Children with DCD are hypothesized to be at increased risk for overweight and obesity from inactivity due to their motor coordination problems. Although previous studies have found evidence to support this hypothesis, their reliance on field-based measures, most notably body mass index (BMI), to determine body composition is problematic. Moreover, there has been no research to date that has examined whether THERE ARE differences in lean tissue mass between children with and without coordination. Differences in muscle mass, the main component of lean tissue, may be a contributing factor to both coordination problems and the development of overweight and obesity, but has only been indirectly examined at this time. In this study, whole-body air displacement using a dual chamber plethysmograph was used to estimate fat mass, fat free mass and body fat in children with probable DCD (pDCD) and a group of typically developing children. Consistent with previous research using field-based assessments of relative body weight, the results show that children with pDCD have much higher body fat than their peers, and that this difference increases with the severity of observed motor coordination difficulties. There was no difference in lean tissue mass between groups. The demonstration of an association between pDCD and body fat using a more sensitive measure of body composition, and evidence showing a dose-response in this relationship, further supports the hypothesis that DCD may be a risk factor for obesity in children.     

Prevalence of suspected developmental coordination disorder and associated factors in Spanish classrooms

BackgroundDevelopmental Coordination Disorder (DCD) is a multifactorial, neurodevelopmental motor disorder that severely affects the activities of a child’s daily life and classroom performance. The aim of this study was to determine the prevalence of suspected DCD in a sample of Spanish schoolchildren and its association with socio-demographic factors.MethodsWe conducted a cross-sectional study including a random sample of 460 children attending mainstream schools in northwest Spain in 2017. A Developmental Coordination Disorder Questionnaire-European Spanish was used to evaluate suspected DCD prevalence. We performed multivariate logistic and linear regression analysis to determine the socio-demographic variables associated with suspected DCD and problematic motor coordination performance.ResultsThe prevalence of suspected DCD was 12.2%. According to the multivariate analysis, DCD symptoms were significantly associated with males (OR = 3.0), ages above 10 years old (OR = 5.0) and low participation in out-of-school physical activities (OR = 2.3). Preterm birth children were twice as likely to show suspected DCD, although this association was not statistically significant (OR = 2.1).ConclusionsA high percentage of Spanish schoolchildren are at risk for developing DCD. There is a strong connection between suspected DCD and socio-demographic factors. Protocols aimed to detect DCD and intervention programmes in classrooms designed to promote motor coordination skills need to take these factors into consideration.     

Evaluation of the Japanese version of the Developmental Coordination Disorder Questionnaire as a screening tool for clumsiness of Japanese children

Developmental Coordination Disorder (DCD) is characterized by clumsiness and coordination difficulties. DCD interferes with academic performance and participation in physical activities and psychosocial functions, such as self-esteem, cognition, or emotion, from childhood through adolescence to adulthood. DCD is a common pediatric condition and its prevalence is estimated to be 6% worldwide. Although English questionnaires are available, there is no questionnaire to identify DCD in Japan, and therefore, no information on its prevalence is available. Recently, we developed the Japanese version of the Developmental Coordination Disorder Questionnaire (DCDQ-J). The purpose of this study was to describe the applicability of the DCDQ-J for use with a community-based population of children in Japan and to investigate the relationships between coordination and attention-deficit hyperactivity disorder (ADHD) tendencies or intelligence. The DCDQ-J was completed by 6330 parents or guardians of children and adolescents. We employed the ADHD-rating scale and determined the intelligence quotient (IQ) of the children. Two-way analysis of variance showed that the scores linearly increased as the children's grades advanced in 2 subscales, namely, control during movement and fine motor. In contrast, non-linear changes were found in the scores of the general coordination subscale. The total scores of the DCDQ-J and ADHD-RS were significantly correlated, but no relationship between DCDQ-J scores and IQ was found. The DCDQ-J is expected to be a useful screening tool to identify and assess motor coordination difficulties of children in Japan and enable cross-cultural comparisons.