Left ventricular structure and function in children with and without developmental coordination disorder

Children with developmental coordination disorder (DCD) are more likely to develop cardiovascular disease risk factors such as obesity and reduced cardio-respiratory fitness. However, there is limited data using laboratory measures for assessing the risk of cardiovascular disease associated with DCD. The purpose of this study was to examine differences in left ventricular structure and function between children with DCD and healthy controls. The study involved 126 children (aged 12-13 years) with significant motor impairment (n = 63) and healthy controls (n = 63) matched for age, sex, and school. The Movement ABC test (M-ABC2) was used to classify children as probable DCD (p-DCD). Cardiac dimensions were measured using ultrasound echocardiography. Left ventricular mass (LVM) was elevated in children with p-DCD (89 ± 17 g) compared to controls (87 ± 21 g), however, this difference was not significant. When LVM was normalized to height^2.7, no difference was evident between groups (26 g and 26 g for the p-DCD and controls, respectively). However, the p-DCD group demonstrated significantly elevated stroke volume (p = 0.02), cardiac output (p < 0.001), end-diastolic volume (p = 0.03), and left ventricle diameter in diastole (p = 0.02). Also, peak VO₂ normalized for fat free mass (FFM) was significantly lower (p = 0.001) and systolic blood pressure (p = 0.01), body mass index (p = 0.001), heart rate (p = 0.005) and percent body fat (p < 0.001) were significantly higher in p-DCD. In regression analyses, p-DCD was a significant predictor of stroke volume and cardiac output even after accounting for height, FFM, VO_2FFM, and sex. Children with p-DCD do not demonstrate significantly elevated LVM or depressed systolic function compared to healthy controls. However, cases with p-DCD demonstrate significantly elevated end-diastolic volume, diastolic chamber size, stroke volume, and cardiac output. These differences indicate obesity related changes in the left ventricle and may represent the early stages of developing left ventricle hypertrophy.     

Evaluating physical activity using accelerometry in children at risk of developmental coordination disorder in the presence of attention deficit hyperactivity disorder

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.     

Gesture production in school vs. clinical samples of children with Developmental Coordination Disorder (DCD) and typically developing children

Dyspraxia, a difficulty in executing an operationalised act, has been associated with Developmental Coordination Disorder (DCD). However, issues relating to the area such as comparisons across modalities, comparisons of school vs. clinical populations, and developmental delay vs. pathology have not been addressed in the same, comprehensive study. In the current study, therefore, familiar gesture production in DCD was addressed in a comprehensive manner to follow-up outstanding issues from previous studies: The production of familiar gestures and praxis imagery in a school (n = 26) vs. clinic sample (n = 19) of children with DCD was examined in relation to typically developing age matched (n = 24) all aged from 9 to 11 years, and two groups of younger children within the age ranges of 5-6 (n = 23) and 4-5 (n = 26) years. Overall, children with Developmental Coordination Disorder showed an impaired ability to produce familiar gestures compared to their typical peers, and this was dependant on the type of gesture and presentation modality. Differences were found between school and clinic samples of children with DCD, suggestive of the recruitment of different underlying mechanisms in the two samples. The results have a bearing on our understanding of the relationship of developmental dyspraxia to DCD, as well as of the issue of developmental delay vs. pathology.     

Pulmonary function in children with development coordination disorder

The purpose of this study was to compare pulmonary function in children with developmental coordination disorder (DCD) with children who are typically developing (TD), and also analyze possible gender differences in pulmonary function between these groups. The Movement ABC test was used to identify the movement coordination ability of children. Two hundred and fifty participants (90 children with DCD and 160 TD children) aged 9-10 years old completed this study. Using the KoKo spirometry, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV_1.0) were used to measure pulmonary function. The 800-m run was also conducted to assess cardiopulmonary fitness of children in the field. There was a significant difference in pulmonary function between TD children and those with DCD. The values of FVC and FEV_1.0 in TD children were significantly higher than in children with DCD. A significant, but low correlation (r = −0.220, p < .001) was found between total score on the MABC and FVC; similarly, a positive but low correlation (r = 0.252, p < .001) was found between total score on the MABC and the completion time of 800-m run. However, no significant correlation between FVC and the time of 800-m run was found (p > .05). Significant correlations between total score on the MABC and the completion time of the 800-m run (r = 0.352, p < .05) and between FVC and the time of 800-m run (r = −0.285, p < .05) were observed in girls with DCD but not boys with this condition. Based on the results of this study, pulmonary function in children with DCD was significantly lower than that of TD children. The field test, 800-m run, may not be a good indicator to distinguish aerobic ability between children with DCD and those who are TD. It is possible that poor pulmonary function in children with DCD is due to reduced physical activity in this population.     

Comorbid ADHD and DCD: examining cognitive functions using the WISC-IV

This study explored the cognitive performance of children with Attention Deficit/Hyperactivity Disorder (ADHD) and/or Developmental Coordination Disorder (DCD) using the Wechsler Intelligence Scale for Children-IV. Participants were 62 children with ages between 9 years 8 months and 12 years 7 months. These children were placed into one of the four groups: Comparison (n = 26), ADHD (n = 14), DCD (n = 11), and ADHD + DCD (n = 11) groups. The ADHD symptoms were assessed using the Australian Disruptive Behaviours Scale, and motor ability was assessed using the McCarron Assessment of Neuromuscular Development (MAND). Significantly poorer perceptual reasoning ability was seen in DCD and ADHD + DCD groups but not in the ADHD group. The findings provide evidence that a deficit in visuo-spatial ability may underlie DCD but not ADHD. These findings revealed different cognitive profiles for ADHD and/or DCD, thus the current study does not lend support to the common aetiology hypothesis in understanding the basis of ADHD and DCD comorbidity.     

Sensory organization of balance control in children with developmental coordination disorder

This study aimed to (1) compare functional balance performance and sensory organization of postural control between children with and without developmental coordination disorder (DCD) and (2) determine the association between postural control and participation diversity among children with DCD. We recruited 81 children with DCD and 67 typically developing children. Balance was evaluated with the Sensory Organization Test (SOT) and the Movement Assessment Battery for Children-2 (Movement ABC-2). Participation patterns were evaluated using the Children Assessment of Participation and Enjoyment assessment. Analysis of variance was used to compare outcome variables between the two groups. A multiple regression analysis was performed to examine the relationship between participation diversity and balance performance in children with DCD. The DCD group had significantly lower Movement ABC-2 balance scores, SOT-derived equilibrium scores, and sensory ratios than the control group (p < 0.05). However, only the Movement ABC-2 balance score was significantly associated with participation diversity in children with DCD. After accounting for the effects of age and gender, Movement ABC-2 balance score remained significantly associated with participation diversity, explaining 10.9% of the variance (F_change1,77 = 9.494, p = 0.003). Children with DCD demonstrate deficits in sensory organization of balance control. This suboptimal balance ability contributes to limited participation in activities.     

Metabolic syndrome in children with and without developmental coordination disorder

Children with developmental coordination disorder (DCD) have higher rates of obesity compared to children with typical motor development, and, as a result may be at increased risk for developing metabolic syndrome (MetS). The purpose of this study was to determine the presence of MetS and its components among children with and without DCD. This nested case-control study classified 63 children scoring below the 16th percentile on the Movement Assessment Battery for Children (M-ABC-2) as probable DCD (pDCD), and 63 controls, all of whom scored above the 16th percentile. Metabolic syndrome was defined using the International Diabetes Federation (IDF) criteria. Eleven children met the criteria for MetS; 8 (72.3%) with pDCD and 3 (27.3%) controls (p = 0.115). Abdominal obesity was found in 39 (30.9%) of children, 29 (46.0%) with pDCD and 10 (15.9%) controls (p < 0.01). Serum triglycerides were higher in pDCD compared to controls, 91.9 mg/dl (63.1) vs. 67.7 mg/dl (33.3) in the control group, p = 0.001. Blood pressure was also significantly higher in the pDCD group, mean systolic BP (110 vs. 105 mmHg, p = 0.01) and mean diastolic BP (69 vs. 65 mmHg, p = 0.01). There were no statistically significant differences between the groups for other components of MetS. The higher prevalence of abdominal obesity and elevated triglycerides and blood pressure in children with pDCD may put them at risk of meeting all criteria of MetS earlier then their peers.     

Taekwondo training improves sensory organization and balance control in children with developmental coordination disorder: a randomized controlled trial

Children with developmental coordination disorder (DCD) have poorer postural control and are more susceptible to falls and injuries than their healthy counterparts. Sports training may improve sensory organization and balance ability in this population. This study aimed to evaluate the effects of three months of Taekwondo (TKD) training on the sensory organization and standing balance of children with DCD. It is a randomized controlled trial. Forty-four children with DCD (mean age: 7.6 ± 1.3 years) and 18 typically developing children (mean age: 7.2 ± 1.0 years) participated in the study. Twenty-one children with DCD were randomly selected to undergo daily TKD training for three months (1 h per day). Twenty-three children with DCD and 18 typically developing children received no training as controls. Sensory organization and standing balance were evaluated using a sensory organization test (SOT) and unilateral stance test (UST), respectively. Repeated measures MANCOVA showed a significant group by time interaction effect. Post hoc analysis demonstrated that improvements in the vestibular ratio (p = 0.003) and UST sway velocity (p = 0.007) were significantly greater in the DCD-TKD group than in the DCD-control group. There was no significant difference in the average vestibular ratio or UST sway velocity between the DCD-TKD and normal-control group after three months of TKD training (p > 0.05). No change was found in the somatosensory ratio after TKD training (p > 0.05). Significant improvements in visual ratios, vestibular ratios, SOT composite scores and UST sway velocities were also observed in the DCD-TKD group after training (p ≤ 0.01). Three months of daily TKD training can improve sensory organization and standing balance for children with DCD. Clinicians can suggest TKD as a therapeutic leisure activity for this population.     

Motor ability and weight status are determinants of out-of-school activity participation for children with developmental coordination disorder

According to the International Classification of Functioning, Disability and Health model endorsed by the World Health Organization, participation in everyday activities is integral to normal child development. However, little is known about the influence of motor ability and weight status on physical activity participation in children with developmental coordination disorder (DCD). This study aimed to (1) compare motor performance, weight status and pattern of out-of-school activity participation between children with DCD and those without; and (2) identify whether motor ability and weight status were determinants of participation patterns among children with DCD. We enrolled 81 children with DCD (boys, n = 63; girls, n = 18; mean age, 8.07 ± 1.5 years) and 67 typically developing children (boys, n = 48; girls, n = 19; mean age, 8.25 ± 1.6 years). Participation patterns (diversity, intensity, companionship, location, and enjoyment) were evaluated with the Children Assessment of Participation and Enjoyment. Motor ability was evaluated with the Movement Assessment Battery for Children, second edition (MABC-2). Other factors that may influence participation such as age, gender, and body weight were also recorded. Analysis of variance was used to compare outcome variables of the two groups, and significant determinants of activity participation were identified by multiple regression analysis. Children with DCD participated in fewer activities (i.e., limited participation diversity) and participated less frequently (i.e., limited participation intensity) than their typically developing peers; however, companionship, location of participation, and enjoyment level did not differ between the two groups. Children in the DCD group demonstrated significantly worse motor ability as assessed by the MABC-2. Further, a greater proportion of children in the DCD group were in the overweight/obese category compared with their typically developing peers. After accounting for the effects of age and gender, motor ability and weight category explained 7.6% and 5.0% of the variance in participation diversity, respectively, for children with DCD. Children with DCD showed less diverse and less intense out-of-school activity participation than typically developing children. Motor impairment and weight status were independently associated with the lower participation diversity. Interventions aiming at improving participation for children with DCD should target weight control and training in motor proficiency. Further study is needed to identify other factors that may hinder participation in this group of children.     

The validity of psychiatric diagnoses: the case of 'specific' developmental disorders

We tested whether developmental coordination disorder (DCD) and mixed receptive expressive language disorder (RELD) are valid diagnoses by assessing whether they are separated from each other, from other childhood disorders, and from normality by natural boundaries termed zones of rarity. Standardized measures of intelligence, language, motor skills, social cognition, and executive functioning were administered to children with DCD (n = 22), RELD (n = 30), autistic disorder (n = 30), mental retardation (n = 24), attention deficit/hyperactivity disorder (n = 53) and to a representative sample of children (n = 449). Discriminant function scores were used to test whether there were zones of rarity between the DCD, RELD, and other groups. DCD and RELD were reliably distinguishable only from the mental retardation group. Cluster and latent class analyses both resulted in only two clusters or classes being identified, one consisting mainly of typical children and the other of children with a disorder. Fifty percent of children in the DCD group and 20% in the RELD group were clustered with typical children. There was no evidence of zones of rarity between disorders. Rather, with the exception of mental retardation, the results imply there are no natural boundaries between disorders or between disorders and normality.     

Identification of emotional and behavioral problems by teachers in children with developmental coordination disorder in the school community

Current evidence on the co-occurrence of Developmental Coordination Disorder (DCD) and psychosocial problems mainly concerns parent-reported information, but rarely includes teacher information. The aim of this study was (1) to investigate the teachers’ identification of emotional and behavioral problems in children with DCD and (2) to examine the performance of the teacher version of the Strengths and Difficulties Questionnaire (SDQ-T) compared with the Teacher Report Form (TRF) in children with DCD. We assessed primary school children (202 boys, 200 girls, range 4–10.8 years, mean age 7.2 years) for DCD following the DSM IV-TR criteria. Emotional and behavioral problems were measured with the TRF (n = 327) and the SDQ-T (n = 361). DCD was established in 23 (5.7%) children, 16 boys and 7 girls (mean age 7.0 years). Children with DCD had a higher proportion of clinical scores on both the TRF Total Problem Scale (TRF TPS) and SDQ-T Total Difficulties Score (SDQ-T TDS). Children with DCD had increased odds on the TRF domains Thought (odds ratio, OR: 5.39), Externalizing (OR: 4.12) and Internalizing (OR: 4.42) problems, and on all SDQ-T-domains and Total Difficulties score (OR: 7.30). In the DCD group the SDQ-T TDS correlated strongly (Spearman's rho 0.80) with the TRF TPS and demonstrated a moderate agreement (Cohen's Kappa 0.53). In conclusion, teachers identified significantly more emotional and behavioral problems in children with DCD compared with their peers. The SDQ-T showed moderate agreement with the TRF in identifying emotional and behavioral problems in children with DCD.     

Development of the Little Developmental Coordination Disorder Questionnaire for preschoolers and preliminary evidence of its psychometric properties in Israel

Purpose

The early identification of motor coordination challenges before school age may enable close monitoring of a child's development and perhaps ameliorate some of the social, psychological and behavioral sequela that often accompany unrecognized Developmental Coordination Disorder (DCD). The purpose of this study was to develop and assess the initial psychometric properties of a screening tool, the Little DCD Questionnaire (Little DCDQ), designed to identify DCD amongst preschoolers aged 3 and 4.

Methods

The suitability of the items of the DCDQ’07 for 3- and 4-year-old children was assessed. Four items were found to be suitable and new items were generated. Content validity was ensured using a Table of Specification and the items were categorized into three sub-categories (Control During Movement, Fine Motor and General Coordination). The Little DCDQ was administered to 146 children (91 boys) aged 3 and 4 (mean age = 49.39 ± 7.16 months). Ninety-one typically developing children were included (mean age = 47.80 ± 7.05 months; 46 boys) while 55 children had been referred or were being treated for some form of developmental delay (mean age = 52.02 ± 6.60 months; 45 boys). Of this sample, 28 parents completed the questionnaire twice within a 2-week interval.

Results

Test-retest reliability was evidenced by moderate to good intraclass correlation coefficient values between scores on the two administrations for the total and the three sub-category scores. Evidence of internal consistency was provided by adequate to high Cronbach's alpha co-efficients calculated for each item, each sub-category score and the total score for the total group, and separately for the control group and the clinically referred group. Validity evidence based on relations to other variables was provided by the finding of significant group differences (clinically referred and control) for the total and sub-category scores for both the age groups and the total group.

Conclusions

Based on the preliminary psychometric evidence, it appears that the Little DCDQ meets many of the necessary standards for validity and reliability as a screening instrument, and shows promise as a useful clinical and research tool.     

Air pollution is associated with brainstem auditory nuclei pathology and delayed brainstem auditory evoked potentials

We assessed brainstem inflammation in children exposed to air pollutants by comparing brainstem auditory evoked potentials (BAEPs) and blood inflammatory markers in children age 96.3 ± 8.5 months from highly polluted (n = 34) versus a low polluted city (n = 17). The brainstems of nine children with accidental deaths were also examined. Children from the highly polluted environment had significant delays in wave III (t(50) = 17.038; p < 0.0001) and wave V (t(50) = 19.730; p < 0.0001) but no delay in wave I (p = 0.548). They also had significantly longer latencies than controls for interwave intervals I-III, III-V, and I-V (all t(50) > 7.501; p < 0.0001), consisting with delayed central conduction time of brainstem neural transmission. Highly exposed children showed significant evidence of inflammatory markers and their auditory and vestibular nuclei accumulated α synuclein and/or β amyloid_1-42. Medial superior olive neurons, critically involved in BAEPs, displayed significant pathology. Children's exposure to urban air pollution increases their risk for auditory and vestibular impairment.     

Understanding physical activity and motivations for children with Developmental Coordination Disorder: An investigation using the Theory of Planned Behavior

Developmental coordination disorder (DCD) is a neurodevelopmental condition, affecting approximately 5–6% of children. Previous research has consistently found children with DCD being less physically active compared to typically-developing (TD) children; however, the psychosocial factors associated with physical activity for children with DCD are poorly understood. The purpose of this study was to examine how theory-based physical activity cognitions impacts physical activity behaviors for children with and without DCD. Participants included a sample of boys (N = 61, M_age = 13.25 ± .46) with DCD (n = 19) and without DCD (n = 42), drawn from a larger prospective cohort study. A questionnaire with psychosocial measures was first administered, and accelerometers were used to assess their physical activity behavior over the subsequent week. Findings indicate that DCD was significantly associated with lower physical activity (F(1,58) = 6.51, p < .05), and poorer physical activity cognitions (F(4,56) Wilks Lambda = 2.78, p < .05). Meditational analyses found attitudes (B = .23, p < .05) and subjective norms (B = .31, p < .05) partially mediating the relationship between DCD and physical activity. Overall, this study further confirms that the activity deficit that exists among boys with DCD, and that the relationship is partially mediated through some physical activity cognitions. Interventions should target the perceived approval of influential people, and the personal evaluations of physical activity for boys with motoric difficulties. These findings further emphasizes the discrepancy in physical activity that exist between boys with DCD and TD boys, and highlight the need to better understand the psychological factors related to physical activity for children with DCD.     

Body awareness in preschool children with psychiatric disorder

The purpose of this study was to investigate the body awareness of preschool children with a psychiatric disorder as measured by the test imitation of gestures (Bergès & Lézine, 1978), using the subsections for pointing to body parts (passive vocabulary) and naming body parts (active vocabulary). Seventy-seven children from 37 to 72 months of age with psychiatric disorders and 67 children without psychiatric disorders were matched for age and sex. A MANOVA indicated no significant interaction effects on the results between the sexes in the psychiatric group and the control group for passive vocabulary (F(1,150) = .59, p ≥ 0.05) or for active vocabulary (F(1,150) = .61, p ≥ 0.05). An ANOVA was conducted to determine the differences between the boys and girls for passive and active vocabulary, and the differences between the psychiatric group and the control group for passive and active vocabulary. No significant differences between the boys and girls for passive vocabulary (F(1,150) = 1.968, p ≥ 0.05) and active vocabulary (F(1,150) = 1.57, p ≥ 0.05) were found. There was a significant difference between the psychiatric and the control group for passive vocabulary (F(1,150) = 9.511, p = 0.002) and active vocabulary (F(1,150) = 16.18, p = 0.00009). The study provides support for the presence of language disorders associated with active and passive body awareness in children with psychiatric disorders compared to typically developing children.     

Short-term motor learning of dynamic balance control in children with probable Developmental Coordination Disorder

PurposeTo explore the differences in learning a dynamic balance task between children with and without probable Developmental Coordination Disorder (p-DCD) from different cultural backgrounds.ParticipantsTwenty-eight Dutch children with DCD (p-DCD-NL), a similar group of 17 South African children (p-DCD-SA) and 21 Dutch typically developing children (TD-NL) participated in the study.MethodsAll children performed the Wii Fit protocol. The slope of the learning curve was used to estimate motor learning for each group. The protocol was repeated after six weeks. Level of motor skill was assessed with the Movement ABC-2.ResultsNo significant difference in motor learning rate was found between p-DCD-NL and p-DCD-SA, but the learning rate of children with p-DCD was slower than the learning rate of TD children. Speed–accuracy trade off, as a way to improve performance by slowing down in the beginning was only seen in the TD children, indicating that TD children and p-DCD children used different strategies. Retention of the level of learned control of the game after six weeks was found in all three groups after six weeks. The learning slope was associated with the level of balance skill for all children. This study provides evidence that children with p-DCD have limitations in motor learning on a complex balance task. In addition, the data do not support the contention that learning in DCD differs depending on cultural background.     

The impact of obesity on developmental coordination disorder in adolescence

Developmental coordination disorder (DCD) as well as overweight and obesity are of increasing importance in the study of human development. Data on the relation between DCD and obesity in adolescence are of particular interest because both phenomena are unlikely to disappear with age. The objective of this study was to determine the impact of obesity on severe DCD in adolescence. A total of 99 obese adolescents aged between 11 and 16 years and 99 normal-weight controls matched for age and gender were included in this cross-sectional study. The Movement Assessment Battery for Children 2 (age band 3) was used to determine subjects’ stage of motor development. Results made clear that (i) obese show a higher severe DCD-risk in comparison to normal-weight adolescents (p < .01) which is (ii) most pronounced in balance (p < .01), and (iii) thereby rather appears in boys (p ≤ .10). Thus, our results at least do not exclude the possibility that obesity might have a detrimental effect on the etiopathology of DCD beyond childhood. Therefore, primary obesity prevention measures may additionally contribute to the prevention of a possible consolidation of severe DCD.     

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.     

Diagnostic validity and reliability of a Korean version of the Parent and Adolescent General Behavior Inventories

Objectives

The purpose of this study was to evaluate the validity and reliability of a Korean version of the Parent General Behavior Inventory-10-item Mania Scale (P-GBI-10M) and the Adolescent General Behavior Inventory (A-GBI) for bipolar and depressive disorder in youths.

Methods

Ninety-two subjects with mood disorder and their parents were recruited from September 2011 to June 2013 through the Department of Psychiatry at the Asan Medical Center, Seoul, Korea. In addition, 125 community participants were recruited through two middle schools and one high school in Seoul. The parents of subjects completed the Parent-version Mood Disorder Questionnaire (P-MDQ), P-GBI-10M and Attention-deficit/hyperactivity disorder Rating Scale (ARS). Adolescents complete the 76-item A-GBI, Beck Depression Inventory (BDI), and Adolescent version of the Mood Disorder Questionnaire (A-MDQ).

Results

Different profiles were evident between the clinic-referred group and the community control, including different P-GBI-10M (t = 3.07, p = 0.003), A-GBI Depressive (t = 4.99, p < 0.001), Hypomanic/Biphasic subscales (t = 3.17, p = 0.002), and BDI (t = 4.76, p < 0.001) scores. The A-GBI Depressive subscale score (t = 3.02, p = 0.003), BDI score (t = 2.12, p = 0.037) and A-GBI Hypomanic/Biphasic subscale score (t = 2.71, p = 0.008) were significantly different between patients with bipolar disorder and those with depressive disorder. Of the 73 items of the Depressive and Hypomanic/Biphasic subscales of the A-GBI, eight discriminated between bipolar and depressive disorder. Furthermore, A-GBI Depressive subscale scores were significantly correlated with BDI (r = 0.81, p < 0.001), A-GBI Hypomanic/Biphasic subscale (r = 0.88, p < 0.001), A-MDQ (r = 0.58, p < 0.001), P-MDQ (r = 0.22, p = 0.005), and ARS (r = 0.26, p < 0.001) scores. Cronbach's α of the A-GBI was 0.98.

Conclusion

The Korean version of the Parent and Adolescent General Behavior Inventories showed excellent internal consistency, fair-to-good construct, and discriminant validity.     

Physical fitness in children with Developmental Coordination Disorder: Measurement matters

Children with Developmental Coordination Disorder (DCD) experience considerable difficulties coordinating and controlling their body movements during functional motor tasks. Thus, it is not surprising that children with DCD do not perform well on tests of physical fitness. The aim of this study was to determine whether deficits in motor coordination influence the ability of children with DCD to perform adequately on physical fitness tests. A case–control study design was used to compare the performance of children with DCD (n = 70, 36 boys, mean age = 8y 1mo) and Typically Developing (TD) children (n = 70, 35 boys, mean age = 7y 9mo) on measures of isometric strength (hand-held dynamometry), functional strength, i.e. explosive power and muscular endurance (Functional Strength Measurement), aerobic capacity (20 m Shuttle Run Test) and anaerobic muscle capacity, i.e. muscle power (Muscle Power Sprint Test). Results show that children with DCD were able to generate similar isometric forces compared to TD children in isometric break tests, but were significantly weaker in three-point grip strength. Performance on functional strength items requiring more isolated explosive movement of the upper extremities, showed no significant difference between groups while items requiring muscle endurance (repetitions in 30 s) and items requiring whole body explosive movement were all significantly different. Aerobic capacity was lower for children with DCD whereas anaerobic performance during the sprint test was not. Our findings suggest that poor physical fitness performance in children with DCD may be partly due to poor timing and coordination of repetitive movements.