Developmental Coordination Disorder and Unhealthy Weight Status in Taiwanese Children: The Roles of Sex and Age.

This study aimed to provide up-to-date information regarding the estimated prevalence of developmental coordination disorder (DCD) in Taiwanese children. Their unhealthy weight status was also examined, as well as the roles of sex and age. This cross-sectional study recruited 825 children aged between 4 and 12 years and categorized them into either typically developing children (TD, >16th percentile) or children at risk for DCD (rDCD, ≤16th percentile) based on the result of the Movement Assessment Battery for Children-2nd edition. Body mass index was calculated to determine weight status (i.e., normal weight, underweight, overweight, and obesity). The estimated prevalence of rDCD was 9.7%. There were significantly more boys in the rDCD groups (p < 0.001). Additionally, preschool children with rDCD were at greater risk for being underweight. However, there was no significant group difference which was found for overweight/obesity. A lower prevalence of rDCD was found in this study. Nevertheless, children with rDCD may be more likely to be underweight in early childhood. Early intervention should be provided to target this population.

Moderation of parental socioeconomic status on the relationship between birth health and developmental coordination disorder at early years.

Objective: This study investigated whether parental SES moderates the effect of birth health on Developmental Coordination Disorder (DCD) in preschool children. Methods: One hundred and twenty-two children aged 4 to 6 years were enrolled in the study. The Movement Assessment Battery for Children --2nd Edition (MABC-2) test was used to assess the motor coordination of children. They were preliminarily categorized into either the DCD (<=16th percentile, n = 23) or typically developing (TD) group (>16th percentile, n = 99) based on the testing results. All children in the DCD group were further confirmed to meet other diagnostic criteria of the DSM-V using the intellectual test and parental questionnaires. Moderation analysis was conducted using the PROCESS macro for SPSS, and 95% confidence intervals with a bootstrap procedure were calculated to identify the significant moderating effect. Results: Maternal education (unstandardized coefficient = 0.6805, SE = 0.3371, p < 0.05) and maternal employment status (unstandardized coefficient = 0.6100, SE = 0.3059, p < 0.05) were found to moderate the relationship between birth length and the probability of having DCD. Moreover, the relationship between birth weight and the probability of having DCD was moderated by the annual household income (unstandardized coefficient = -0.0043, SE = 0.0022, p < 0.05). Conclusion: The lower maternal education level and maternal unemployment strengthened the negative relationship between birth length and the probability of having DCD. Additionally, the negative relationship between birth weight and the probability of having DCD was statistically significant in high annual household salaries.

Perceptual and Motor Performance of Combat-Sport Athletes Differs According to Specific Demands of the Discipline.

The specific demands of a combat-sport discipline may be reflected in the perceptual-motor performance of its athletes. Taekwondo, which emphasizes kicking, might require faster perceptual processing to compensate for longer latencies to initiate lower-limb movements and to give rapid visual feedback for dynamic postural control, while Karate, which emphasizes both striking with the hands and kicking, might require exceptional eye-hand coordination and fast perceptual processing. In samples of 38 Taekwondo athletes (16 females, 22 males; mean age = 19.9 years, SD = 1.2), 24 Karate athletes (9 females, 15 males; mean age = 18.9 years, SD = 0.9), and 35 Nonathletes (20 females, 15 males; mean age = 20.6 years, SD = 1.5), we measured eye-hand coordination with the Finger-Nose-Finger task, and both perceptual-processing speed and attentional control with the Covert Orienting of Visual Attention (COVAT) task. Eye-hand coordination was significantly better for Karate athletes than for Taekwondo athletes and Nonathletes, but reaction times for the upper extremities in the COVAT task-indicative of perceptual-processing speed-were faster for Taekwondo athletes than for Karate athletes and Nonathletes. In addition, we found no significant difference among groups in attentional control, as indexed by the reaction-time cost of an invalid cue in the COVAT task. The results suggest that athletes in different combat sports exhibit distinct profiles of perceptual-motor performance.

High risk for obesity in children with a subtype of developmental coordination disorder.

The purpose of this study was to compare the prevalence of overweight and obesity in typically developing (TD) children, children with developmental coordination disorder (DCD) and balance problems (DCD-BP), and children with DCD without balance problems (DCD-NBP). Two thousand and fifty-seven children (1095 boys, 962 girls) ages 9-12 years were recruited from 18 elementary schools in Taiwan. The Movement Assessment Battery for Children was used to assess motor coordination ability. International cut-off points for body mass index were used to classify participants into the following groups: normal-weight, overweight or obese. Compared with TD children, children in the DCD-BP group were more than twice as likely to be obese (OR=2.28; 95% CI=1.41-3.68). DCD-BP children were also more likely to be obese compared to DCD-NBP children (OR=1.79; 95% CI=1.02-3.16). Boys in the DCD-BP group were more likely to be obese when compared to DCD-BP girls (OR=3.12; 95% CI=1.28-7.57). Similarly, DCD-NBP boys were more likely to be obese when compared to DCD-NBP girls (OR=2.67; 95% CI=1.21-5.89). Children with both DCD and BP were significantly more likely to be obese when compared to TD and DCD-NBP children. From an intervention perspective, the inclusion of regular physical activity, including activities that encourage development of both balance and energy expenditure, may be required to prevent obesity in this population.

Deficits in the covert orienting of attention in children with Developmental Coordination Disorder: does severity of DCD count?

Children with Developmental Coordination Disorder (DCD) show deficits in the covert orienting of visuospatial attention, suggesting an underlying issue in attentional disengagement and/or inhibitory control. However, an important theoretical issue that remains unclear is whether the pattern of deficits varies with DCD severity. Fifty-one children with moderate DCD (MDCD), 24 children with severe DCD (SDCD), and 38 typically developing (TD) children participated in the study. Their performance was compared on the covert orienting of visuospatial attention task (COVAT), specifically the voluntary control mode. Results showed that the pattern of performance differed between groups. At a short stimulus-response asynchrony (350 ms), the difference in response times for validly and invalidly cued trials was similar for all three groups. However, at the longer SOA (800 ms), both DCD groups continued to show a relative disadvantage for responses that followed invalid cues. This suggests that a deficit in response inhibition and/or attentional disengagement is manifest in children with both moderate and severe DCD. The implications of these findings for theory and treatment are discussed.

Motor coordination and health-related physical fitness of children with developmental coordination disorder: a three-year follow-up study.

Health-related physical fitness is an important risk factor of cardiovascular disease. While previous studies have identified children with developmental coordination disorder (DCD) to be less physically fit than typically developing (TD) peers, there is limited longitudinal research in this area. This study was undertaken to evaluate concomitant changes in motor coordination and health-related physical fitness of Taiwanese children with and without DCD over a three-year period. The Movement Assessment Battery for Children (Movement ABC) test was used to evaluate motor coordination, while health-related physical fitness included several core components: (1) body mass index (BMI), (2) sit and reach forward, (3) long jump, (4) sit-ups, and (5) 800-m run. Both the Movement ABC and fitness tests were implemented once each a year for three years. Twenty-five children with DCD and 25 TD children, matched by age and gender participated in this study. The TD group showed significant long-term changes in BMI and long jump while the DCD group showed significant increases in BMI values and decreases in flexibility, measured by the sit and reach task. In general, children with DCD performed worse on the items of flexibility, muscle strength and muscle endurance after the first year. Compared to age- and gender-matched norms, children with DCD not only were less physically fit, but showed a significant long-term decline in flexibility and abdominal or core strength (sit-ups). In years two and three, there was a significant negative correlation between poor fitness and motor coordination. Based on the results of this longitudinal study, greater attention should be paid to monitoring and improving physical fitness of children with DCD to prevent further health-related problems while intervention.

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 1s (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.

Obesity and motor coordination ability in Taiwanese children with and without developmental coordination disorder.

The purpose of this study was to investigate the associations between obesity and motor coordination ability in Taiwanese children with and without developmental coordination disorder (DCD). 2029 children (1078 boys, 951 girls) aged nine to ten years were chosen randomly from 14 elementary schools across Taiwan. We used bioelectrical impedance analysis to measure percentage of body fat (PBF) and the Movement Assessment Battery for Children test (MABC test) to evaluate the motor coordination ability. Using cut-off points based on PBF from past studies, boys and girls were divided into obese, overweight and normal-weight groups, respectively. In boys, total impairment scores and scores on balance subtest in the MABC were significantly higher in the obese and overweight groups when compared against the normal-weight group. Girls in the obese and the overweight groups had higher balance impairment scores than those of the normal-weight group. Among boys, the prevalence of obesity was highest in the DCD group, when compared to the borderline DCD and TD boys. A higher percentage of DCD girls were overweight and obese than TD girls. Obesity may be associated with poor motor coordination ability among boys and girls, and particularly in relation to balance ability. Children with DCD may have a higher risk to be overweight or obese in Taiwan.

Development and initial validation of the Preschooler Gross Motor Quality Scale.

Motor skills have great impact on children in adapting to an environment and developing interpersonal interaction, cognition, and social behavior. Understanding what children can do and how they perform it is essential. Most motor tests seldom contain quality evaluation in the items or criteria. The purpose of this study was to develop and construct validity of the Preschooler Gross Motor Quality Scale (PGMQ) that included 17 items in three subscales to evaluate the quality of fundamental motor skills for the preschooler. The study designed PGMQ items and subscales according to well-described procedures, and recruited 174 children, aged 3-6 (89 boys and 85 girls) from 17 kindergartens. Two independent evaluators who were unaware of each other's results evaluated all the children separately in their kindergartens using PGMQ standardized setting and procedures and Gross Motor Scales of Peabody Developmental Motor Scales II (PDMS-II). Results of this study found significant differences between different ages and genders (Wilks'Λ=0.221, p<.001 and Wilks'Λ=0.690, p<.001 respectively). Total scores and raw scores in three subscales of PGMQ increased as age increased. Confirmatory factor analysis revealed three factors, including locomotion, manipulative ability and balance to explain 51.06% of the variance. The correlations between PGMQ and PDMS-II subscales were moderate to high (r=0.544-0.868, p<.01). The results showed satisfactory validity of PGMQ. PGMQ is useful to evaluate the development and quality of fundamental motor skills for the preschoolers.

Cardiopulmonary fitness and endurance in children with developmental coordination disorder.

The purpose of this study was to compare cardiopulmonary fitness and endurance in 9-11-year-old children with DCD against a group of typically developing children in Taiwan. The Movement ABC test was used to evaluate the motor abilities of children. Forty-one participants (20 children with DCD and 21 children without DCD) were recruited for this study. The cardiopulmonary tests included the 800-m run test and the peak oxygen consumption (peak VO(2)) test using the Bruce treadmill protocol. No significant differences in age, body height, body weight, body mass index, and percentage of body fat between children with DCD and without DCD were found. However, there were significant differences in the cardiopulmonary endurance tests between children with DCD and without DCD. Children with DCD had significantly lower peak VO(2) results than children without DCD. In addition, children with DCD ran 800 m in a slower time than children without DCD. A significant negative correlation (r=-0.437) was found between the peak VO(2) results and time to completion for the 800-m run test. Based on the results, cardiopulmonary endurance in children with DCD was worse than that of children without DCD. Due to the small sample size in this study, the results may not be a direct reflection of the entire population.

Role of visual-perceptual skills (non-motor) in children with developmental coordination disorder.

The purposes of this study were to examine test-retest reliability of the Test of Visual-Perceptual Skills (Non-Motor)-Revised (TVPS-R), to explore motor-free visual-perceptual skills, and to categorize subtypes thereof in children with developmental coordination disorder (DCD). One hundred and seventy-eight children, aged 9 and 10 years, identified as having DCD with the Movement Assessment Battery for Children (M-ABC), were assessed, along with 200 typically developing children. The results showed good test-retest reliability for the total perceptual quotient scores of the TVPS-R, but not for all subtests. Children with DCD performed significantly poorer compared to typically developing children on the visual-perceptual test, but the deficits were not common to all children with DCD. This study supported the stance that we should consider the heterogeneous characteristics of children with DCD when designing experimental studies or developing educational interventions.

Static balance in children with developmental coordination disorder.

The purpose of this study was to compare the postural sway profiles of 9/10-year-old children with developmental coordination disorder and balance problems (DCD-BP, n=64) with those of non-DCD children (n=71). We measured center of pressure excursions in conditions with and without vision for 30s while standing still on the dominant leg, the non-dominant leg, or both legs. Sway area, total path length, and Romberg's quotient were analyzed. Most measures differed significantly between groups, except sway area when the children stood with vision on either the dominant leg or both legs. When standing on the dominant leg or both legs, DCD-BP children demonstrated greater total path length in all conditions and a greater sway area in without-vision conditions. DCD-BP children showed more difficulty standing on the non-dominant leg with eyes both open and closed. While boys showed results similar to the total group, the girls with DCD-BP only exhibited significant differences in three conditions with eyes closed, but not with eyes open. Analysis of Romberg's coefficient also indicated that children with DCD-BP did not over-rely on visual information.