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.     

Physical fitness and overweight in Israeli children with and without developmental coordination disorder: Gender differences

Physical fitness and overweight among children has become paramount in the general population and more so in children with developmental coordination disorder (DCD). The purpose of the current study was to examine the association between physical fitness and overweight in a sample of Israeli children in comparison to typical children, and to examine gender differences. DCD was identified through total scores on the movement assessment battery for children 2 (MABC-2) equal to or less than the 16th percentile as well as parents’ report that the child's deficits in motor skills interfered with at least two daily life activities. The sample included a group of children with DCD (n = 22, M age = 8.70 [SD = 1.36], 16 boys [73%]) and a control group of typical children (n = 47, M age = 8.90 [SD = 1.52], 34 boys [72%]). Measures included the strength subtest of the Bruininks–Oseretsky test of motor proficiency (BOT-2), the six minutes’ walk test (6MWT) with heart rate measure, BMI and the percentage of body fat. Significant differences between DCD and typical children were found on all variables of physical fitness and weight. A two-way analysis of variance (ANOVA) analysis (group/gender) also revealed significant interactions for the percentage of body fat (F = 8.51, p < .005) and BMI (F = 4.50, p < .038) meaning that less fit children are more obese. The current study supports previous findings that children with DCD are less physically fit and more overweight compared to typically developing children. Moreover, in comparing between the genders, the girls in the study sample weighed more and had a significantly higher percentage of body fat than boys, it is essential to further our understanding of the relationships between obesity, physical fitness and gender among children with and without DCD.     

The prenatal,perinatal and neonatal risk factors for children's developmental coordination disorder: A population study in mainland China

We initially conducted a population-based study on developmental coordination disorder (DCD) in mainland China to explore the prenatal, perinatal and neonatal risk factors on DCD. A total of 4001 children were selected from 160 classes in 15 public nursery schools. The Movement Assessment Battery for Children-Second Edition (MABC-2) was used to assess the children's motor function. Crude and adjusted odds ratios were estimated to determine the strength of association using a multilevel logistic regression model with a random intercept. Three hundred and thirty children out of 4001 subjects met the DSM-IV criteria for DCD, and 3671 children were non-DCD. Maternal age, threatened abortion, fetal distress during labor, preterm birth, chronic lung disease and newborn pathological jaundice were related with DCD (OR = 1.72, 2.72, 9.14, 5.17, 1.43, and 2.54, respectively, each p < 0.05). Considered collectively, these risk factors may provide clues to an etiology of DCD. Additionally, the practitioners of maternity and child health care should improve the assessment and monitoring of the prenatal, perinatal and neonatal risk factors for DCD.     

Differential effect of Taekwondo training on knee muscle strength and reactive and static balance control in children with developmental coordination disorder: A randomized controlled trial

This randomized controlled trial aimed to investigate the effect of short-term intensive TKD training on the isokinetic knee muscle strength and reactive and static balance control of children with developmental coordination disorder (DCD). Among the 44 children with DCD (mean age: 7.6 ± 1.3 years) recruited, 21 were randomly assigned to undergo daily TKD training for 1 h over three consecutive months, with the remaining 23 children being assigned to the DCD control group. Eighteen typically developing children (mean age: 7.2 ± 1.0 years) received no training as normal controls. Knee extensor and flexor muscle strength and reactive and static balance control were assessed using an isokinetic machine (with low, moderate and high movement velocities), a motor control test (MCT) and a unilateral stance test (UST), respectively. A repeated measures MANCOVA revealed a significant group through time interaction effect in isokinetic outcomes at 180°/s and in the UST outcome. Post hoc analysis demonstrated that DCD-TKD children's isokinetic knee muscle strength, specifically at 180°/s, was as high as that of the normal control children (p > 0.0083) after TKD training. Moreover, UST body sway velocity was slower in the DCD-TKD group than in the DCD control group (p < 0.001), and was comparable to that of the normal control group (p > 0.05) after TKD training. However, no such improvement in balance was observed in the MCT (p > 0.025). The results show that children with DCD who undergo a 3-month program of intensive TKD training experience improvements in isokinetic knee muscle strength at 180°/s and static single-leg standing balance control, but do not benefit from improved reactive balance control.     

The influence of Chinese one-child family status on Developmental Coordination Disorder status

We conducted a population-based study on Developmental Coordination Disorder (DCD) in mainland China to explore the influence of one-child status in Chinese families on DCD. A total of 4001 children selected from 160 classes in 15 public nursery schools. The Movement Assessment Battery for Children assessed motor function. The prevalence of DCD in Chinese one-child families (8.7%) was higher than that in multi-child families (5.9%). Chinese one-child family status (compared with younger children in multi-child families) were negatively related with total score (−1.793), Manual dexterity (−0.228), Aiming and catching (−1.145), Balance (−0.433) of MABC-2 and DCD (OR = 2.294) when adjusted for the children's and family's characteristics, and perinatal factors (each p < 0.05). As one of the studies in this Chinese context, it provides a platform for future intervention programs in one-child families in preventing children's developmental disorders.     

Assessment of physical fitness and exercise tolerance in children with developmental coordination disorder

Children with developmental coordination disorder (DCD) have been shown to be less physically fit when compared to their typically developing peers. The purpose of the present study was to examine the relationships among body composition, physical fitness and exercise tolerance in children with and without DCD. Thirty-seven children between the ages of 7 and 9 years participated in this study. Participants were classified according to results obtained on the Movement Assessment Battery for Children (MABC) and were divided in 2 groups: 19 children with DCD and 18 children without DCD. All children performed the following physical fitness tests: The five-jump test (5JT), the triple-hop distance (THD) and the modified agility test (MAT). Walking distance was assessed using the 6-min walking test (6MWT). Children with DCD showed higher scores than children without DCD in all MABC subscale scores, as well as in the total score (p < 0.001). Participants with DCD were found to perform significantly worse on the MAT (p < 0.001), the THD (p < 0.001) and 5JT (p < 0.05). Moreover, children with DCD had poorer performance on the 6MWT than children without DCD (p < 0.01). Our results found significant correlations among body mass index (BMI), THD (r = 0.553, p < 0.05), 5JT (r = 0.480, p < 0.05) and 6MWT (r = 0.544, p < 0.05) only in DCD group. A significant correlation between MAT and 5JT (r = −0.493, p < 0.05) was found. Similarly, THD and 5JT (r = 0.611, p < 0.01) was found to be correlated in children with DCD. We also found relationships among 6MWT and MAT (r = −0.522, p < 0.05) and the 6MWT and 5JT (r = 0.472, p < 0.05) in DCD group. In addition, we found gender specific patterns in the relationship between exercise tolerance, explosive strength, power, DCD, and BMI. In conclusion, the present study revealed that BMI was indicative of poorer explosive strength, power and exercise tolerance in children with DCD compared to children without DCD probably due to a limited coordination on motor control.     

Factors influencing the motor development of prematurely born school-aged children in Brazil

Despite technological advances in neonatology, premature children are still susceptible to disruptions in neurological development. The current study aimed to analyze the factors that influence motor development in prematurely born school-aged children in Brazil. This cross-sectional study involved 100 “apparently normal” children, aged 8–10 years, born at less than 35 weeks of gestation or with birth weight < 1500 g. Their motor development was assessed using the Movement Assessment Battery for Children (MABC-2). The children's neuropsychological and academic performance was assessed with the Token Test (TT) and Teste de Desempenho Escolar (TDE), respectively. Parents answered questions regarding the child's clinical history and behavior using the Strengths and Difficulties Questionnaire (SDQ) and family environment resources (RAF). Hierarchical multivariate analyses revealed that 39% of the children scored lower on the MABC-2, as compared to that expected for their age (manual dexterity: 49%; balance: 35%; throwing/catching a ball: 26%). Multivariate analysis indicated that the lower the birth weight, the maternal age at childbirth, and the RAF score, the greater was the chance of impairment on the MABC-2 scores. The probability of having an impairment MABC-2 scores was four times higher when the mother was not employed. We also found associations between MABC-2 scores and the tasks of tying shoes and opening/closing zippers and buttons. Factors related to children's home environments and birth weight are associated with deficient motor performance in prematurely born Brazilian school-aged children. Deficient motor skills were also associated with difficulty in performing functional tasks requiring greater manual dexterity.     

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.     

A physical fitness follow-up in children with cerebral palsy receiving 12-week individualized exercise training

Physical fitness in children with cerebral palsy (CP) is lower than in their peers. A 12-week individualized home-based exercise program completed by 11 children with CP 10 years earlier showed a favorable effect on physical fitness performance. We follow-up the physical fitness of those 11 children with CP, and compare their physical fitness and health-related quality of life (HRQoL) to children with CP without exercise training matched with age and motor levels. Eleven children with CP in the 2003 program as a follow-up group (FUG) and 12 volunteers recruited as a control group (CG) participated in this study. Physical fitness measures, including cardiopulmonary endurance, muscle strength, body mass index (BMI), flexibility, agility, balance, and the SF-36 Taiwan version, were assessed in both groups. After 10 years, the FUG showed better physical fitness in cardiopulmonary endurance and muscle strength (p < .05). Compared to the CG, the FUG demonstrated better muscle strength, agility, and balance (p < .05). However, the HRQoL did not show a significant difference between the FUG and the CG. Individualized home-based exercise training is beneficial for children with CP. Over 10 years, the FUG was more devoted to physical activity than was the CG. Physical exercise may not directly affect the HRQoL in this study.     

Effects of aerobic,resistance and balance training in adults with intellectual disabilities

Adults with intellectual disability (ID) have decreased cardiovascular fitness and strength present with lower rates of physical activity (PA), and often have balance and functional impairments. The purpose of this study was to investigate the effect of a combined PA program (CPAP) utilizing aerobic, strength and balance training on cardiovascular fitness, strength, balance and functional measures in a controlled clinical trial. Adults with mild to moderate ID were assigned into either the intervention group (IG; n = 37) or the control group (CG; n = 29). The IG trained 3 day/week, 1 h/day over 14 weeks, while the CG did not participate in any exercise program. Cardiovascular fitness, strength, balance, flexibility and functional ability were assessed pre-post training. The IG increased cardiovascular fitness (26.8 vs. 29.3 ml kg⁻¹ min⁻¹), handgrip strength (19.2 vs. 21.9 kg), leg strength, and balance following the training period (p < .05). Body weight (70.1 vs. 68.1 kg) and body mass index (27.4 vs. 26.6 kg m⁻²) decreased (p < .05) in the IG group. The CG showed no changes in any parameter. These data suggest a combined aerobic, strength and balance exercise training program is beneficial among individuals with ID.     

Neural underpinnings of impaired predictive motor timing in children with Developmental Coordination Disorder

A dysfunction in predictive motor timing is put forward to underlie DCD-related motor problems. Predictive timing allows for the pre-selection of motor programmes (except ‘program’ in computers) in order to decrease processing load and facilitate reactions. Using functional magnetic resonance imaging (fMRI), this study investigated the neural correlates of motor timing in DCD (n = 17) and typically developing children (n = 17). The task involved motor responses to sequences of visual stimuli with predictive or unpredictive interstimulus intervals (ISIs). DCD children responded with a smaller reaction time (RT) advantage to predictive ISIs compared to typically developing children. Typically developing children exhibited higher activation in the right dorsolateral prefrontal cortex (DLPFC) and right inferior frontal gyrus (IFG) for responses at unpredictive as opposed to predictive ISIs, whereas activations in DCD children were non-differentiable. Moreover, DCD children showed less activation than typically developing children in the right DLPFC, the left posterior cerebellum (crus I) and the right temporo-parietal junction (TPJ) for this contrast. Notably, activation in the right temporo-parietal junction (TPJ) positively correlated with RT as an indicator of processing load in both groups. These data indicate that motor performance in DCD children requires extra processing demands due to impaired predictive encoding.     

Activity participation intensity is associated with skeletal development in pre-pubertal children with developmental coordination disorder

PurposeThis study aimed (1) to compare the skeletal maturity and activity participation pattern between children with and without developmental coordination disorder (DCD); and (2) to determine whether activity participation pattern was associated with the skeletal development among children with DCD.Materials and methodsThirty-three children with DCD (mean age: 7.76 years) and 30 typically developing children (mean age: 7.60 years) were recruited. Skeletal maturity was assessed with the Sunlight BonAge system. Motor ability was evaluated by the Movement assessment battery for Children-2 (MABC-2). Participation patterns were evaluated using the Children Assessment of Participation and Enjoyment assessment. Analysis of variance was used to compare the outcome variables between the two groups. Multiple regression analysis was performed to examine the relationship between skeletal development, motor performance and activity participation intensity in children with DCD.ResultsThe DCD group had significantly delayed skeletal development, lower MABC-2 derived scores, and participated less intensely in various types of physical activities than their typically developing peers. After accounting for the effects of age and sex, activity participation intensity score remained significantly associated with delay in skeletal development, explaining 28.0% of the variance (F_{change1, 29} = 11.341, p = 0.002).ConclusionSkeletal development is delayed in pre-pubertal children with DCD. Limited activity participation intensity appears to be one of the contributing factors.     

Psychometric properties of the DCD-Q-07 in children ages to 4–6

It is important to identify Developmental Coordination Disorder (DCD) early in a child's life to allow for proper and timely intervention and support, and to reduce the negative secondary consequences associated with this condition. In this study we assessed the psychometric properties (construct validity, concurrent validity, reliability and test accuracy) of the Developmental Coordination Disorder Questionnaire (DCD-Q-07) in preschool children. A community-based sample of children ages 4–6 (n = 181) were screened for motor difficulties using the Movement Assessment Battery for Children (M-ABC-2). Use of the M-ABC-2 resulted in the identification of 29 children below the 15th percentile, which we classified as probable DCD. Parents of these children concurrently completed the DCD-Q-07 to report their child's motor performance. The DCD-Q-07 demonstrated high internal consistency for both the full scale (alpha = 0.881) and each subscale: control during movement (alpha = 0.813), fine motor and handwriting (alpha = 0.869) and general coordination (alpha = 0.728). Moderate correlations (r = 0.47–0.63) were also seen between the subscales on the DCD-Q-07, the strongest correlation being between control during movement and general coordination (r = 0.63). Based on published age and sex cut points, the DCD-Q-07 showed poor sensitivity (20.7%) but high specificity (92.1%) against the M-ABC-2. Overall agreement with the M-ABC-2 was low using ROC analysis (area under the curve = 0.654). Although it is important to screen for DCD in young children, the DCD-Q-07 may not be the best choice as a screening tool for DCD in preschool children ages 4–6 due to its low test accuracy.     

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 VO₂) 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 VO₂ 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 VO₂ 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.     

Psychometric properties of the DCDDaily-Q: A new parental questionnaire on children's performance in activities of daily living

Difficulties in the performance of activities of daily living (ADL) are a key feature of developmental coordination disorder (DCD). The DCDDaily-Q was developed to address children's motor performance in a comprehensive range ADL. The aim of this study was to investigate the psychometric properties of this parental questionnaire. Parents of 218 five to eight year-old children (DCD group: N = 25; reference group: N = 193) completed the research version of the new DCDDaily-Q and the Movement Assessment Battery for Children-2 (MABC2) Checklist and Developmental Coordination Disorder Questionnaire (DCDQ). Children were assessed with the MABC2 and DCDDaily. Item reduction analyses were performed and reliability (internal consistency and factor structure) and concurrent, discriminant, and incremental validity of the DCDDaily-Q were investigated. The final version of the DCDDaily-Q comprises 23 items that cover three underlying factors and shows good internal consistency (Cronbach's α > .80). Moderate correlations were found between the DCDDaily-Q and the other instruments used (p < .001 for the reference group; p > .05 for the DCD group). Discriminant validity of the DCDDaily-Q was good for DCDDaily-Q total scores (p < .001) and all 23 item scores (p < .01), indicating poorer performance in the DCD group. Sensitivity (88%) and specificity (92%) were good. The DCDDaily-Q better predicted DCD than currently used questionnaires (R² = .88). In conclusion, the DCDDaily-Q is a valid and reliable questionnaire to address children's ADL performance.     

Executive function and attention in young adults with and without Developmental Coordination Disorder – A comparative study

The current research aimed at examining the executive function (EF) of young adults with Developmental Coordination Disorder (DCD) in comparison to young adults without DCD. The study used a randomized cohort (N = 429) of young adults with DCD (n = 135), borderline DCD (n = 149) and control (n = 145), from a previous study. This initial cohort was asked to participate in the current study three to four years later. Twenty-five individuals with DCD (mean age = 24 years, 1 month [SD = 0.88]; 18 males), 30 with borderline DCD (mean age = 24 years, 2 month [SD = 0.98]; 18 males) and 41 without DCD (mean age = 25 years, 2 months [SD = 1.91]; 20 males) participated in this study. Participants completed the BRIEF-A questionnaire, assessing EF abilities and the WURS questionnaire, assessing attention abilities. The DCD and borderline DCD groups had significantly lower EF profiles in comparison with the control group but no significant differences were found between the DCD and borderline DCD groups. While a high percentage of attention problems were found in both DCD groups, the executive functioning profiles remained consistent even when using the attention component as a covariate. The study results suggest that young adults with DCD have EF problems which remain consistent with or without attention difficulties.     

Developmental Coordination Disorder in children with specific language impairment: Co-morbidity and impact on quality of life

Co-morbidity of Developmental Coordination Disorder (DCD) in children with specific language impairment (SLI) and the impact of DCD on quality-of-life (QOL) was investigated in 65 5–8 year old children with SLI (43 boys, age 6.8 ± 0.8; 22 girls, age 6.6 ± 0.8). The prevalence of DCD was assessed using DSM-IV-TR criteria (American Psychiatric Association (APA), 2000) operationally defined in the clinical practice guideline (CPG): movement ABC scores below 15th percentile, scores on DCDQ and/or MOQ-T below 15th percentile, absence of medical condition according to paediatric-neurological exam. Quality of life (QOL) was measured with the TNO-AZL-Child-Quality-Of-Life (TACQOL) Questionnaire filled out by parents for the SLI group with and without DCD, and compared to a reference group (N = 572; age 6.9 ± 0.9). The TACQOL covers 7 QOL domains: physical, motor, cognitive and social functioning, autonomy, positive and negative moods. Prevalence of DCD in children with SLI was 32.3%. In children with SLI, mean QOL scores were significantly lower in the autonomy, cognitive, social and positive moods domains compared to the reference group. Children with SLI and DCD differed from children with SLI without DCD by significantly lower mean overall-, motor-, autonomy-, and cognitive domain-QOL scores. Clinicians should be aware that about one third of children with SLI can also be diagnosed with DCD. Assessment of QOL is warranted in order to assess which domains are affected in children with SLI with or without DCD.     

Psychological distress in children with developmental coordination disorder and attention-deficit hyperactivity disorder

This study explored whether or not a population-based sample of children with developmental coordination disorder (DCD), with and without comorbid attention deficit/hyperactivity disorder (ADHD), experienced higher levels of psychological distress than their peers. A two-stage procedure was used to identify 244 children: 68 with DCD only, 54 with ADHD only, 31 with comorbid DCD and ADHD, and 91 randomly selected typically developing (TD) children. Symptoms of depression and anxiety were measured by child and parent report. Child sex and caregiver ethnicity differed across groups, with a higher ratio of boys to girls in the ADHD only group and a slightly higher proportion of non-Caucasian caregivers in the TD group. After controlling for age, sex, and caregiver ethnicity, there was significant variation across groups in both anxiety (by parent report, F(3,235) = 8.9, p < 0.001; by child report, F(3,236) = 5.6, p = 0.001) and depression (parent report, F(3,236) = 23.7, p < 0.001; child report, F(3,238) = 9.9, p < 0.001). In general, children in all three disorder groups had significantly higher levels of symptoms than TD children, but most pairwise differences among those three groups were not significant. The one exception was the higher level of depressive symptoms noted by parent report in the ADHD/DCD group. In conclusion, children identified on the basis of motor coordination problems through a population-based screen showed significantly more symptoms of depression and anxiety than typically developing children. Children who have both DCD and ADHD are particularly at heightened risk of psychological distress.     

Aggressive interactions during free-play at preschool of children with and without developmental coordination disorder

This aim of this study was to investigate an unexpected finding from a larger study examining the play of preschool children with and without developmental coordination disorder (DCD). We found that children with DCD were more frequently involved in aggressive incidents during free-play than their peers. Children with (n = 32) and without DCD (n = 31) were videotaped during free-play at preschool and their play was assessed using the Play Observation Scale. A post hoc analysis was conducted using a specifically developed rating instrument to examine the aggressive incidents captured on video. Videos from 18 children with DCD and 8 typically developing children without DCD were found to contain aggressive incidents. Children with DCD were significantly more often involved as both aggressor (p = .016) and victim (p = .008) than children without DCD (p = .031). This is the first study to identify victimization and aggression as being problematic for children with DCD as young as 4 years of age and needs replication. Given the negative consequences of involvement in aggression and victimization, play-based early intervention focusing on prevention needs to be developed and implemented.