Physical fitness in children with developmental coordination disorder: measurement matters

Evaluating the Efficacy of Gross-Motor-Based Interventions for Children with Developmental Coordination Disorder: A Systematic Review

Objectives: This review quantitatively evaluates the effectiveness of gross-motor-based interventions in children with developmental coordination disorder (DCD), examining treatment aspects such as group interventions, therapy duration, and frequency. Methods: A systematic literature review, spanning January 2010 to December 2022, identified 11 relevant articles involving 492 children. Results: Positive outcomes were observed, with a moderate to large overall effect size (Cohen's d) indicating significant improvements in motor function through strategies emphasizing activity, bodily function, games, and small group events. Notably, interventions targeting complex motor skills were crucial for enhancing preparedness and activity engagement, improving fitness, and preventing obesity in children with DCD. Conclusions: The review underscores the effectiveness of activity-oriented and body-function-focused therapies in enhancing motor skills and functioning, emphasizing the need for interventions aligned with real-world activities. Future research should explore the long-term effects and retention of motor improvements, offering valuable insights for designing targeted interventions to promote overall well-being in children with DCD.

Which outcomes are key to the pre-intervention assessment profile of a child with developmental coordination disorder? A systematic review and meta-analysis

BACKGROUND

Purpose of this study was to determine what key aspects of function should be incorporated to make up a pre-intervention assessment profile of a child with Developmental Coordination Disorder (DCD); more specifically, what aspects of functioning are implicated in DCD and what is their relative impact?

METHODS

A systematic review and meta-analysis were conducted, for which Pubmed, Web of Science, Scopus and Proquest were searched (last update: April 2023, PROSPERO: CRD42023461619). Case-control studies were included to determine point estimates for performances on field-based tests in different domains of functioning. Risk of bias was assessed, and level of evidence estimated. Random-effect meta-analyses were performed to calculate the pooled standardized mean differences for domains of functioning and subgrouping was done for clinically relevant subdomains. Heterogeneity was determined with I2.

RESULTS

121 papers were included for analyses. Data of 5 923 children with DCD were included (59.8% boys) and 23 619 Typically Developing (TD) children (45.8% boys). The mean (SD) age of the DCD group was 10.3y (1.2) and 9.3y (1.3) for the TD children. Moderate evidence was found for motor performance, executive functions, sensory processing and perceptions, cognitive functions and sports and leisure activities to be affected in children with DCD.

CONCLUSION

Differences between the two groups varied per domain of functioning. This emphasizes the diversity present within children with DCD and provides a rationale for explaining the heterogeneity in this patient group. Yet, results highlight the potential involvement of all these domains and call for clinicians to be alert not only to examine motor skill difficulties but also other aspects of function. Results indicate the need to develop an individualized pre-intervention multi-dimensional assessment profile for each child with DCD. It also supports the important role that clinicians play in an interdisciplinary team to tackle the difficulties encountered by children with DCD.

The strength of balance: Strength and dynamic balance in children with and without hypermobility

BACKGROUND

Generalized Joint hypermobility (GJH) is predominantly non-symptomatic. In fact, individuals with joint flexibility usually perform better than their non-hypermobile counterparts during physical activities. Notwithstanding, strength and balance are essential to maintain the control of the extra range of motion during activities and to prevent musculoskeletal complications. There are limited and conflicting pieces of evidence in literature regarding the association between strength and balance in children with GJH.

OBJECTIVES

The purpose of this study was to examine differences in functional strength, dynamic balance, proprioception, and isometric strength in children with and without joint hypermobility and determine the association between strength outcomes and dynamic balance.

METHOD

A cross-sectional study was conducted among children aged 6 to 11. Hypermobility was determined using the Beighton Score, with scores ≥6 representing hypermobility. Functional strength was assessed with the Functional Strength Measure (FSM), isometric strength was determined with a handheld dynamometer (HHD), the Y-Balance Test (YBT) was used to assess dynamic balance and the Wedges test to measure proprioception.

RESULTS

This study included 588 participants (age: 7.97 ± 1.3 years; height: 128±10.1 cm; mass: 27.18 ± 7.98 kg). 402 children were classified as having normal mobility and 186 as being hypermobile. Hypermobile children had better functional strength in the lower extremities than children with normal range mobility but lower reach distance in the YBT. No differences in proprioception, functional strength of the upper extremity or isometric strength in the hands were found. However, isometric lower extremity force was less in hypermobile children than children with normal range mobility. Irrespective of their joint mobility, a fair significant correlation existed between total Y-balance distance and FSM items r = 0.16-0.37, p = 0.01. Correlations between total Y-balance distance and isometric strength of knee and ankle muscles ranged between r = 0.26-0.42, p = 0.001.

CONCLUSION

Hypermobile joints seem to co-occur with lower extremity isometric strength, more functional strength in the lower extremities and less reaching distance in dynamic balance. The opposing direction of the results on functional and isometric strength tests highlights the importance of the type of outcome measures used to describe the association of strength and the range of motion.

Activities of daily living, self-efficacy and motor skill related fitness and the interrelation in children with moderate and severe Developmental Coordination Disorder

BACKGROUND

Children with Developmental Coordination Disorder (DCD) are diagnosed based on poor motor skills that impact their daily activities. However, this may also lead to lower predilection and participation in physical activities and a higher risk to develop health problems.

OBJECTIVE

To determine motor skill related levels in children with moderate and severe DCD and compare that to typically developing children (TD). The study also aimed to determine the level of activities of daily living (ADL) as reported by their parent and self-efficacy as reported by the children. Lastly, the relation of motor skill related fitness, ADL, and self-efficacy has been examined.

METHODS

A cross-sectional study has compared TD children (n = 105) and children with DCD (n = 109; 45 moderate DCD and 64 severe DCD) from elementary schools in Tunisia between 7 and 10 years of age. The DCDDaily-Questionnaire and Children's Self-perceptions of Adequacy in and Predilection for Physical Activity Questionnaire have been used to determine ADL and adequacy towards physical activity, respectively. The PERF-FIT has been used to measure motor skill related fitness levels.

RESULTS

Large group differences (p = 0.001) were found for ADL and all domains of self-efficacy between TD and DCD children. However, ADL and self-efficacy were not different between moderate and severe DCD. Motor skill related fitness was significantly lower (p = 0.01) for children with DCD than TD children, and between children with moderate and severe DCD. The relation between self-efficacy and DCDDaily-Q was different in the two DCD groups. Slow motor learning was associated with lower perceived enjoyment in physical education in the moderate DCD group, and with lower perceived adequacy in physical education in the severe DCD group.

CONCLUSIONS

Children with DCD participate and enjoy physical activity less than their peers. This combination of lower participation, lower predilection to physical activity and lowered motor skill-related fitness is a concern for the present and future health status of children with DCD.

Spatial Accuracy and Variability in Dart Throwing in Children with Developmental Coordination Disorder and the Relationship with Ball Skill Items

The present study aimed to examine precision and variability in dart throwing performance and the relationships between these outcomes and bouncing, throwing and catching tasks in children with and without DCD. Children between the ages of 8 and 10 years (n = 165) were classified according to results obtained on the Movement Assessment Battery for Children (MABC-2) and divided into three groups: 65 children with severe DCD (s-DCD), 45 with moderate DCD (m-DCD) and 55 typically developing children (TD). All children performed the dart throwing test and the ball skill items of the Performance and Fitness Test (PERF-FIT). The accuracy and variability of dart throwing tasks were significantly different between TD and s-DCD (p < 0.01), and also between m-DCD and s-DCD (p < 0.01). Participants with s-DCD were also found to perform significantly worse on all PERF-FIT ball skill items than m-DCD (p < 0.001), and m-DCD were significantly poorer than TD (p < 0.001). The dart score and coefficient of variation of the long-distance task appear to be significant predictors for the ball skills and explain between 24 to 29% of their variance. In conclusion, poor results in aiming tasks using darts in children with DCD corroborate with the explanation of deficits in predictive control since the tasks require ballistic movements.

Physical Fitness in Children With Developmental Coordination Disorder: A Systematic Review

OBJECTIVE

To synthesize evidence about physical fitness levels in children with developmental coordination disorder (DCD) compared with typically developing (TD) children.

METHODS

We searched four databases (PubMed, Scopus, Web of Science, and PsycINFO) for cross-sectional, case-control, and cohort studies comparing physical fitness between children with and without DCD. We assessed the methodological quality of the studies with the Newcastle-Ottawa Scale (NOS). We calculated Cohen's d effect sizes to provide clinical evidence of group differences in aerobic capacity, anaerobic capacity, muscle strength, body composition and flexibility.

RESULTS

We included 32 studies for qualitative synthesis after applying eligibility criteria. All selected studies ranged from moderate to high research quality. Effect sizes in favor of typically developing children over children with DCD were large for aerobic capacity (d = 1.15), anaerobic capacity (d = 0.90), and muscle strength (d = 0.79), and small for body composition (d = 0.43) and flexibility (d = 0.21) outcomes.

CONCLUSION

Children with DCD presented significantly lower physical fitness than their typically developing peers, particularly in aerobic and anaerobic capacity and in muscle strength.

Effectiveness and feasibility of We12BFit!: improving physical fitness and lifestyle physical activity in children with developmental coordination disorder in a paediatric rehabilitation setting-a small sample field study

OBJECTIVES

To examine the effectiveness and feasibility of We12BFit!, a family-focused intervention aimed at increasing physical fitness (PF) and motivation for physical activity (PA) in 7-year-old to 12-year-old children with developmental coordination disorder (DCD).

DESIGN

A single-arm mixed methods small sample field study.

SETTING

Rehabilitation centres and schools for special education in The Netherlands.

PARTICIPANTS

Twenty children with DCD diagnosis.

INTERVENTIONS

We12BFit! consists of We12BFit!-PF and We12BFit!-Lifestyle PA. During We12BFit!-PF, cardiorespiratory fitness (CRF), muscle strength and anaerobic power were trained in small groups (10 weeks 2*60 min/week). We12Bfit!-Lifestyle PA, which addresses motivation for PA in children and parents, was added in week 6 of We12BFit!-PF and ended 12 weeks after We12BFit!-PF.

OUTCOME MEASURES

The 20-Metre Shuttle Run Test (20mSRT), Muscle Power Sprint Test and Hand Held Dynamometry were performed before and after We12BFit!-PF and after We12BFit!-Lifestyle PA (T0-T1-T2). Parents and coaches were interviewed and trainers participated in a focus group to assess motivation for PA, perceived effectiveness, and feasibility of the intervention.

RESULTS

Attendance rates of participants were 88% (We12BFit!-PF) and 89% (We12BFit!-Lifestyle PA). From T0 to T1, significant improvements were found in VO_2peak, number of runs on the 20mSRT and mean anaerobic power. From T1 to T2, improvements were maintained. No changes were found after We12BFit!-Lifestyle PA in time spent on moderate to vigorous activity and metabolic equivalent of task; parents observed their child improved in qualitative aspects of activities and participation. Feasibility of We12Bfit! was confirmed, although some adaptations were recommended.

CONCLUSIONS

We12BFit! resulted in significant improvements and maintenance of CRF and anaerobic power in a small group of children with DCD and seemed to improve motivation for PA. The group aspect of We12BFit!-PF, the high intensity and positive motivational climate of We12BFit!-PF may have improved children's self-efficacy. We12BFit! seems feasible to improve PF and PA in children with DCD.

TRIAL REGISTRATION NUMBER

NTR6334.

Evaluation of cardiopulmonary system outcomes in children with developmental coordination disorder: A systematic review

BACKGROUND

children with Developmental Coordination Disorder (DCD) tend to avoid physical activity, which can affect their health and well-being.

AIM

Conduct a systematic review to identify, synthesize and compile data from the literature on the evaluation of the cardiopulmonary system in children with DCD.

METHOD

According to PRISMA guidelines, we searched for articles indexed in PubMed, LILACS, Scopus, Web of Science, and Cochrane Library. The strategy was directed at the Population (children), Exposure (DCD), Outcomes (descriptors related to cardiopulmonary evaluation).

RESULTS

A total of 59 articles were identified through the databases. In the end, after analyzing the titles, abstracts, and full articles, including articles through manual search in the lists of bibliographic references, 13 articles relevant to the topic were included. All selected studies evaluated cardiorespiratory fitness / aerobic capacity parameters, and only three studies included the assessment of lung function.

CONCLUSION

Although very heterogeneous, the evidence found in this review suggests that children with DCD have less cardiorespiratory fitness and lower lung function when compared to children with typical development. However, new studies are suggested to investigate and strengthen the evidence found in the present study.

Children with Poor Motor Skills Have Lower Health-Related Fitness Compared to Typically Developing Children

Most of the current empirical evidence regarding the relationship between health-related fitness and level of motor performance is based on children from high-income countries. Yet, children from low-resource areas may have fewer opportunities to develop their fitness skills. The aim of the study was to determine if South African children from both low- and middle-income areas scoring below the 16th percentile on the Movement Assessment Battery for Children-2 (probable-Developmental Coordination Disorder (p-DCD)) have lower health-related fitness levels than typically developing (TD) children. We hypothesized that children with p-DCD would have lower overall health-related fitness than TD children. A sample of 146 participants aged 10 to 11 (10.05 years (SD = 0.41)) was collected from schools in the North West Province of South Africa, on the basis of their poverty classification. Children were tested for anaerobic capacity and strength using the Bruininks-Oseretsky test of motor proficiency second edition (BOT-2) and aerobic capacity using the Progressive Aerobic Cardiovascular Endurance Run (PACER). Body composition was evaluated using body mass index corrected for age and sex (BMI-z), body fat (BF), and waist circumference. The data was analyzed using Spearman correlations and chi-squared tests. Statistically significant differences (p < 0.05) were found between groups for running and agility, strength, and aerobic capacity. No significant differences were found between p-DCD and TD groups in terms of body mass (36.1 kg vs. 33.3 kg), waist circumference (62.2 cm vs. 59.8 cm), BMI-z (19.7 vs. 17.6), and fat percentage (20.2 vs. 18.1%). Overweight and obesity prevalence was 15% in those with low socio-economic status (SES) and 27% in high SES. In conclusion, children with p-DCD had lower muscular strength, aerobic capacity, and endurance than TD children. Although it has been reported that children with p-DCD have a higher risk for overweight/obesity than TD children, this is not (yet) the case in 10-11-year-old children living in rural areas in South Africa (North West Province).

Ecological validity of the PERF-FIT: correlates of active play, motor performance and motor skill-related physical fitness

Background

Active games are important health enhancing physical activities in children with and without developmental disorders and will help children to develop fundamental motor skills, while inactivity exacerbates coordination difficulties and increases the risk of obesity. Regular engagement in active play promotes physical, social and cognitive development. It is therefore important to know if children have the capabilities for healthy behavior. Motor skills and muscular fitness are both important components to participate in play, sport and leisure. The Performance and Fitness (PERF-FIT) test battery integrates motor skills (running, jumping, hopping, catching, bouncing, throwing, balance) and muscular fitness (explosive power and muscular endurance) needed in many forms of active play.

Aim

To test the ecological validity of the PERF-FIT test battery; a field-based test integrating motor skill proficiency and muscular fitness.

Methods

Seventy-five children were assessed on the PERF-FIT, Movement Assessment Battery for Children (MABC)-2 and performance in 6 active games was scored. Of these children, 52 children scored in the normal range and 23 (or 30.3%) below the 16^th percentile of the MABC-2. Association between the outcomes of the two tests and the 6 games was calculated.

Results

High to moderate associations were found between game scores and PERF-FIT items; moderate to low associations between game scores and MABC-2 items. Principle axes factor analysis with oblique rotation revealed communalities between the explosive power and agility items of the PERF-FIT and the running and ball catching games but not between the games and the balance items.

Conclusions and implications

Scores on the PERF-FIT are significantly related to performance in active play. The tool is able to measure aspects of motor skills, muscle endurance and explosive power needed in children's active games and could be used as an additional tool to measure requirements for participation in everyday physical activity in children with and without developmental disorders.

Effects of Graded Exergames on Fitness Performance in Elementary School Children With Developmental Coordination Disorder

Developmental Coordination Disorder (DCD) is a common childhood disorder affecting movement and coordination skills, fitness, and academic performance. Increased physical fitness may have a positive influence on physical and mental health outcomes in children with DCD. Yet, little has been done to develop interventions to improve fitness performance in this group. The purpose of this study was to determine the effects of graded exergames in 7 to 12-year-old children with DCD and typically developing (TD) peers. Participants (32 DCD and 28 TD children) received a 30-min training session twice weekly for 10 weeks. Performance on motor coordination (MABC-2 test), balance, aerobic, and anaerobic fitness tests were assessed at the beginning and end of training. In addition, enjoyment and perception of exertion were measured for each participant during the training period. Both children with DCD and TD children significantly improved on motor coordination, balance, aerobic, and anaerobic fitness at the end of the training. A significant Group by Time interaction was observed on the MABC-2 total [F (1, 55) = 13.19; p < 0.001] and balance scores [F (1, 55) = 26.83; p < 0.0001], with the DCD group demonstrating larger improvements than the TD children. Both groups enjoyed the program throughout the training period even though they rated the training to be of high intensity. These findings indicate that graded exergames may serve as potential treatment for impaired fitness in children with DCD. Regular participation in graded exergames in school settings may be needed to enhance and maintain fitness performance in young children with and without DCD.

Differences in walking and running gait in children with and without developmental coordination disorder: A systematic review and meta-analysis

BACKGROUND

Developmental coordination disorder (DCD) is a common motor skills disorder in children. Although gait changes are often reported clinically, affecting children's participation in play and sport, there has been no synthesis of research evidence comparing gait of children with and without DCD. Thus, the aim of this research was to determine differences in gait between children with and without DCD METHODS: A search of electronic databases (AMED, CINAHL, Cochrane Library, Embase, Medline, SPORTDiscus, & Web of Science) was conducted from inception to August 2019 for studies comparing walking and/or running gait of children with and without DCD. The McMaster Critical Appraisal Form for Quantitative Studies was used to assess risk of bias amongst included studies. Meta-analysis was completed on measures with four or more homogenous outcomes.

RESULTS

20 studies fulfilled the inclusion criteria and were eligible for review - three of which were pre-post designs, and 17 were cross-sectional designs. Data was extracted in five domains: kinetics, kinematics, physical function, electromyography, and temporospatial parameters. Meta-analysis was performed on one outcome measure - the 6 min Walk Test (6MWT), finding that children with DCD walked significantly shorter distances, indicating reduced endurance in walking gait. Other statistically significant results all favoured typically developing children, however there is little consistency between studies.

CONCLUSION

Although a clear gait pattern for children with DCD is not evident, functional deficits appear to be present in endurance and cardiorespiratory fitness. The current evidence base for gait changes in DCD is currently low-level, and further high quality research is warranted.

PROSPERO REGISTRATION NUMBER

CRD42018106791.

Effects of Acute and Chronic Exercises on Executive Function in Children and Adolescents: A Systemic Review and Meta-Analysis

Background: Physical exercises can affect executive function both acutely and chronically, with different mechanisms for each moment. Currently, only a few reviews have elaborated on the premise that different types of exercises have different mechanisms for improving executive function. Therefore, the primary purpose of our systematic review was to analyze the effects of acute and chronic exercises on executive function in children and adolescents. Objective: We identified acute and chronic exercise studies and randomized controlled trials (RCTs) of executive function in children and adolescents that reported overall effect, heterogeneity, and publication bias of acute and chronic exercises on executive function. Methods: We searched for RCTs of exercise interventions in children and adolescents from databases including PubMed, Web of Science, Scopus, The Cochrane Library, CNKI (China National Knowledge Infrastructure), and Wanfang, from January 1 2009 to December 31 2019. We performed methodological quality evaluations on the included literature using the Physiotherapy Evidence Database Scale (PEDro) and graded evidence with a meta-analysis using Stata 12.0 software. Results: In total, 36 RCTs were included (14 acute exercises, 22 chronic exercises); the overall results of the meta-analysis (4,577 students) indicated that acute exercises significantly improved working memory (standardized mean difference (SMD) = -0.72; 95% confidence interval (CI) -0.89 to -0.56; p < 0.001), inhibitory control (SMD = -0.25; 95% CI -0.40 to -0.09; p = 0.002), and cognitive flexibility (SMD = -0.34; 95% CI -0.55 to -0.14; p < 0.005), whereas chronic exercises significantly improved working memory (SMD = -0.54; 95% CI -0.74 to -0.33; p < 0.001), inhibitory control (SMD = -0.30; 95% CI -0.38 to -0.22; p < 0.001), and cognitive flexibility (SMD = -0.34, 95 % CI -0.48 to -0.20, p < 0.001). Conclusion: Acute and chronic exercises can effectively improve the executive function of children and adolescents. The effects on inhibitory control and cognitive flexibility are considered as small effect sizes, while the effects on working memory are considered as moderate effect size. Limited by the quantity and quality of the included studies, the above conclusions need to be verified with more high-quality studies.

Children With Developmental Coordination Disorder Show Altered Visuomotor Control During Stair Negotiation Associated With Heightened State Anxiety

Safe stair negotiation is an everyday task that children with developmental coordination disorder (DCD) are commonly thought to struggle with. Yet, there is currently a paucity of research supporting these claims. We investigated the visuomotor control strategies underpinning stair negotiation in children with (N = 18, age = 10.50 ± 2.04 years) and without (N = 16, age = 10.94 ± 2.08 years) DCD by measuring kinematics, gaze behavior and state anxiety as they ascended and descended a staircase. A questionnaire was administered to determine parents' confidence in their child's ability to safely navigate stairs and their child's fall history (within the last year). Kinematics were measured using three-dimensional motion capture (Vicon), whilst gaze was measured using mobile eye-tracking equipment (Pupil labs). The parents of DCD children reported significantly lower confidence in their child's ability to maintain balance on the stairs and significantly more stair-related falls in the previous year compared to the parents of typically developing (TD) children. During both stair ascent and stair descent, the children with DCD took longer to ascend/descend the staircase and displayed greater handrail use, reflecting a more cautious stair negotiation strategy. No differences were observed between groups in their margin of stability, but the DCD children exhibited significantly greater variability in their foot-clearances over the step edge, which may increase the risk of a fall. For stair descent only, the DCD children reported significantly higher levels of state anxiety than the TD children and looked significantly further along the staircase during the initial entry phase, suggesting an anxiety-related response that may bias gaze toward the planning of future stepping actions over the accurate execution of an ongoing step. Taken together, our findings provide the first quantifiable evidence that (a) safe stair negotiation is a significant challenge for children with DCD, and that (b) this challenge is reflected by marked differences in their visuomotor control strategies and state anxiety levels. Whilst it is currently unclear whether these differences are contributing to the frequency of stair-related falls in children with DCD, our findings pave the way for future research to answer these important questions.

Field-Based Tests of Strength and Anaerobic Capacity Used in Children With Developmental Coordination Disorder: A Systematic Review

OBJECTIVE

Children with developmental coordination disorder (DCD) are reported to have lower levels of strength and anaerobic capacity. The purpose of this study was to (1) identify field-based tests for strength and anaerobic capacity used in studies comparing children with DCD and children who were typically developing (TD), (2) examine the methodological quality of studies reporting psychometric properties and rate the psychometric properties of the examined test, and (3) summarize available evidence by combining the methodological quality of the studies and the quality of the psychometric properties of the test.

METHODS

An electronic search was conducted in July 2019 in 4 electronic databases. For purpose 1, primary studies were included with no exclusion of study design in which children aged 4 to 18 years with DCD were compared with children who were TD on strength and/or anaerobic capacity measures. For purpose 2, primary studies were included with no exclusion of study design in which a psychometric property was investigated. The Consensus-Based Standards for Selection of Health Measurement Instruments (COSMIN) was used to evaluate the methodological quality of the 34 studies and rate the psychometric properties of the tests used.

RESULTS

Hand-held dynamometer, bent knee push-up, vertical jump, standing long-jump, functional strength measurement, fitness test, and test battery can be recommended for TD, and the shuttle run item of the Bruininks-Oseretsky Test of Motor Proficiency-Second Edition and 10 m × 5 m sprints (straight and slalom) can be recommended for DCD.

CONCLUSION

Information regarding psychometric properties of field-based tests for strength and anaerobic capacity in children with DCD is lacking.

IMPACT

Information about the psychometric properties of field-based tests for strength and anaerobic capacity in children with DCD is lacking. More information is available on TD children, but it is also not complete; information regarding validity and responsiveness, especially, is missing. When using measures in children with DCD, it is important to keep in mind this lack of evidence for the validity and reliability of the outcomes for this target group.

Growth and muscle strength development in children with developmental coordination disorder

AIM

To assess effects of growth on lower limb maximal isometric muscle strength (MIMS) development in children with developmental coordination disorder (DCD).

METHOD

This observational study used hand-held dynamometry to evaluate MIMS (hip abductors, flexors, extensors; knee flexors and extensors; ankle dorsiflexors) in children with DCD (n=33, 12 females, 21 males, 6-12y, mean [SD] age 9y [2y]). Regression analysis compared changes in MIMS for similar changes in growth (height or body mass) for children with DCD and typically developing children (pre-existing database, n=183), controlling for age and sex.

RESULTS

For the same height gain, the gain in muscle strength was 37.3% to 69.2% less in children with DCD compared with typically developing children, with significantly lower slopes (p-value between <0.001-0.042) in all muscle groups tested except knee extensors and ankle dorsiflexors in females. Strength gains related to body mass gains were not different for children with DCD compared to typically developing children.

INTERPRETATION

Even when growing at a similar rate, children with DCD do not develop muscle strength gains at the same rate as their typically developing peers.

WHAT THIS PAPER ADDS

Strength gains with growth (height) may be reduced in children with developmental coordination disorder.

Exploring associations between neuromuscular performance, hypermobility, and children's motor competence

OBJECTIVES

To evaluate if neuromuscular performance and hypermobility are factors associated with children's motor competence.

DESIGN

Cross-sectional observation study.

METHODS

Data was collected on 60 children aged 6-12 years; motor competence was determined using the Movement Assessment Battery for Children-2 test, with children classified into 3 groups (Typically Developing n=30; 'At Risk' of low motor competence (LMC) n=9; LMC n=21). Neuromuscular performance was determined utilising the Resistance Training Skills Battery for Children (RTSBc), 5-repetition maximum (5RM) leg press and Biodex dynamometry to assess isometric and isokinetic peak torque of the knee flexors and extensors. Hypermobility was measured using the Beighton and Lower Limb Assessment Score.

RESULTS

Between-groups MANCOVA revealed typically developing children scored significantly higher on the RTSBc than those 'at risk' of LMC (p=0.021) and those in the LMC group (p<0.001). 5RM scores also differed between groups, with typically developing children achieving significantly higher scores than the LMC group. No differences were found between groups for isometric or isokinetic measures of strength. Sequential regression analysis revealed neuromuscular performance variables explained 44.7% of the variance in motor competence, with RTSBc (p<0.001) and 5RM (p=0.019) emerging as positive significant predictors. Hypermobility failed to explain significant variance in motor competence beyond that explained by neuromuscular performance.

CONCLUSIONS

Neuromuscular performance of children varies according to levels of motor competence, with those with LMC performing poorly on tasks requiring multi-joint movement. Furthermore, neuromuscular performance predicted almost half the variance observed in motor competence and highlights a novel intervention strategy.

Predicting physical activity in a national cohort of children born extremely preterm

Predicting physical activity in a national cohort of children born extremely preterm.

OBJECTIVES

To compare physical activity among school-aged children born extremely preterm or with extremely low birthweight (EP/ELBW) to term-born children, and to identify early predictors for physical inactivity in the EP/ELBW-children.

METHODS

A national cohort born during 1999-2000 at gestational age < 28 weeks or birthweight <1000 g and term-born controls were assessed. EP/ELBW-children without neurodevelopmental disabilities were labeled "healthy". At five years, we examined the EP/ELBW-children's motor, mental and intellectual functioning using the Movement Assessment Battery for Children (MABC), The Strength and Difficulties Questionnaire (SDQ) and The Wechsler Preschool and Primary Scale of Intelligence-revised. At 11 years, the parents reported their children's physical activity (PA) in questionnaires.

RESULTS

Information was obtained from 231/372 EP/ELBW and 57/61 term-born children. At 11 years, EP/ELBW-children had fewer exercise events per week, were less engaged in team sports, had lower endurance, lower sports proficiency, and were less vigorous during PA than term-born children (p < 0.05). Low sports proficiency in the healthy EP/ELBW-children at 11 years was predicted (odds ratio; 95% confidence interval) by abnormal MABC-score (3.0; 1.0 to 8.7), and abnormal SDQ-score (4.0; 1.6 to 10.0) at 5 years. Lower endurance at PA was predicted by abnormal MABC-score (2.6; 1.0 to 6.6), abnormal SDQ-score (3.0; 1.4 to 6.5), and borderline intellectual functioning (4.2; 1.8 to 10.1).

CONCLUSIONS

Eleven-year-old EP/ELBW-children were less physically active than term-born. In healthy EP/ELBW-children, impaired motor coordination, borderline intellectual functioning and behavioral problems at 5 years of age predicted unfavorable PA habits at 11 years.

Children's Repetitive and Intermittent Sprinting Performance (CRISP) Test: A new field-based test for assessing anaerobic power and repeated sprint performance in children with developmental coordination disorder

BACKGROUND

Evidence on anaerobic power and sprinting performance of children with Developmental Coordination Disorder (DCD) is limited.

AIMS

The primary aim of this study was to investigate if the Children's Repetitive and Intermittent Sprinting Performance (CRISP) test could induce fatigue among participants. Secondly, the study examined the construct validity of the test in children with probable DCD (p-DCD) and typically developing (TD) peers.

METHODS AND PROCEDURES

The study was carried out in two phases. In phase 1, we compared performance of 25 children (7-12 years) on the CRISP test to their performance on the Muscle Power Sprint test (MPST). For phase 2, forty-six (n = 46) participants with p-DCD were matched with TD children (n = 46) on age, weight and sex. Anaerobic performance of participants was assessed using the CRISP test, 10 × 5 m sprints straight and slalom tests, side jumps, stepping on platform task and the ladder agility test.

OUTCOMES AND RESULTS

Phase 1: The increase in running time on the CRISP test was greater than on the MPST, indicating that the CRISP test was more fatiguing than the MPST. Phase 2: Children with p-DCD had poorer anaerobic capacity (muscle power, muscle endurance) compared to their TD peers. However, fatigue was comparable between the two groups. The differences in performance between p-DCD and TD children were found to be greater for tests with more agility elements.

CONCLUSIONS AND IMPLICATIONS

The findings showed that CRISP test could induce fatigue in children. The CRISP test was also found to have positive construct (i.e. known-group) validity. The differences in muscle power and endurance between children with p-DCD and TD peers tend to widen when assessments are performed with tests having high agility components.

Physiological characteristics, self-perceptions, and parental support of physical activity in children with, or at risk of, developmental coordination disorder

Children with low movement proficiency have been identified as having poorer physiological and psychosocial outcomes; however, the varied measurement approaches used to assess these outcomes have varied resulting in conflicting evidence regarding the presence and magnitude of differences compared to Typically Developing (TD) children. Additionally, there has been limited research into the role of parental support for physical activity (PA) in this group. We compared children with varying levels of movement proficiency on physiological characteristics and self-perceptions regarding PA. In addition, these children's parents were compared on physiological characteristics and support of their children's PA. Children (N = 117) aged 6 to 12 years, along with their parent/guardian, participated in this study. Children were classified according to the Movement Assessment Battery for Children-2 test (Typically Developing (TD) = 60; At Risk = 19; Developmental Coordination Disorder (DCD) = 38). Children's PA, muscle strength, cardio-respiratory fitness (CRF), body composition, and self-perceptions regarding PA were assessed, with parents assessed on CRF, body composition, and PA support. Compared to TD children, children with DCD had lower PA (p = 0.036), predilection (p ≤0.001) and adequacy (p ≤0.001) regarding PA, higher body fat percentage (p = 0.019), and received less logistic support (i.e., transportation) from their parents (p = 0.012). TD children had increased muscle strength compared to the DCD (p ≤ 0.001) and At Risk (p ≤ 0.001) groups. Results indicated that, relative to TD children, children with DCD have multiple physiological deficits, receive less parental logistic support for PA involvement, and report lower scores on psychological constructs that are predictive of PA involvement.

The Prevalence of Left-Handedness Is Higher Among Individuals With Developmental Coordination Disorder Than in the General Population

Many medical, psychiatric and neurological conditions have been characterized by a high prevalence of left-handedness or mixed-handedness. Several studies have indicated an elevated frequency of left-handedness in children with Developmental Coordination Disorder (DCD). However, there have been few studies explicitly exploring this relationship. The assumption is that the prevalence of left-handedness in individuals with DCD is higher compared with the prevalence in the general population and resembles the prevalence described in children with other developmental disorders. Computerized searches were conducted in PubMed, PsycInfo and CINAHL databases. Thirty-eight studies were identified and included in the present review, containing handedness distributions across 1071 persons with DCD and 1,045 controls. The distribution of DCD participants across handedness-categories was proved to be significantly different from that of the control group, with 14.7 and 8.1% left-handers, respectively. The prevalence of left-handedness within the DCD-group is lower than that reported for ASD, and larger than in dyslexia. The elevated levels of left-handedness within the different developmental disorders supports the notion of an association between the different diagnoses. However, the present results are not sufficient to conclude anything about a common cause or underlying factor via the male hormone testosterone. The present results could act as a starting point for testing the hypothesis of such a common factor, as one of the requirements is an elevated prevalence of left-handedness, and without such considerable doubt would be cast upon the hypothesis.

Subtyping children with developmental coordination disorder based on physical fitness outcomes

PURPOSE

Children with Developmental Coordination Disorder (DCD) are known to have poor physical fitness. However, differentiating homogenous subgroups of DCD using fitness performance has not yet been established. Therefore the purpose of this study was to identify subtypes in children with and without DCD using measures of physical fitness.

METHOD

Children (aged 6-10 years, n = 217) constituted the sample for this study. They were assessed on 1) aerobic fitness (20m Shuttle Run test), 2) anaerobic fitness (Muscle Power Sprint Test), 3) isometric muscle strength (handheld dynamometry) 4) functional upper and lower body strength (Functional Strength Measurement) and 5) motor coordination [Movement Assessment Battery for Children-2nd edition (MABC-2) test]. The Ward method was used to identify the various clusters.

RESULTS

Five subtypes emerged in the entire sample. In the typically developing (TD) children mainly 2 subtypes (number 5 and 2) were found containing 89% of the TD children (n = 55), with the largest group demonstrating above average performance on all measures (cluster 5). Children in subtype 2 had just above average motor coordination and good aerobic fitness but lower muscle strength. Subtypes 1, 3 and 4 were clearly "DCD" clusters, however they showed difference in fitness performance. Subtype 1 contained children with DCD who showed poor performance on all fitness outcomes (n = 45). Children with DCD in subtype 3 had poor aerobic but average strength and anaerobic fitness (n = 48). Subtype 4 contained children with DCD (n = 45) who had good muscle strength and anaerobic fitness. Of these, 36% were at risk of DCD while 24% had definite motor coordination problems.

CONCLUSION

Our findings indicate that children with and without DCD demonstrate heterogeneous physical fitness profiles. The majority of the children (66%) with DCD belonged to subtypes with lower fitness performance. Further studies are needed to confirm these findings in other samples of DCD children.

Psychometric properties of field-based anaerobic capacity tests in children with Developmental Coordination Disorder

Background: Assessment of anaerobic capacity in children with Developmental Coordination Disorder (DCD) is essential for treatment planning. However, available field-based measures have no established validity and reliability in this population. Purpose: To examine the psychometric properties of selected field-based anaerobic capacity tests in children with and without DCD. Methods: School-aged children (6-16 years) with and without DCD participated in the study. The children completed the shuttle run sub-item of the Bruninks-Oseretsky test of motor proficiency-second edition, the 10 × 5 m sprint tests (straight and slalom) and the muscle power sprint test (MPST). Results: The shuttle run test item of the Bruninks-Oseretsky test of motor proficiency-second edition and 10 × 5 m sprint tests possess good construct validity and test-retest reliability in children with DCD. The 10 × 5 m sprint test-slalom was found to be the most responsive test among children with DCD. However, the MPST was less reliable in children with DCD compared to their typically developing peers, leading to a very large Smallest Detectable Difference. Conclusions: The findings suggest that the selected anaerobic capacity measures have sound psychometric properties among children with DCD with the exception of the MPST. Clinicians working on children with DCD could use these tests in their practice, especially in situations where logistical resources are limited. Implications for Rehabilitation Field-based anaerobic capacity tests are suitable measures for assessing anaerobic capacity in children with Developmental Coordination Disorder, particularly in situations where laboratory assessments are not feasible. The shuttle run test item of the Bruninks-Oseretsky test of motor proficiency-second edition and the 10 × 5 sprint tests (straight and slalom) have good construct validity in this population. The 10 × 5 sprint test (slalom) is the most sensitive anaerobic capacity test among children with Developmental Coordination Disorder.

The efficacy of two activity-based interventions in adolescents with Developmental Coordination Disorder

BACKGROUND

Adolescents with Developmental Coordination Disorder (DCD) usually experience psychomotor difficulties that affect their participation in everyday tasks and sports. Without effective intervention, adolescents show persistent motor deficits through adulthood. It is therefore critical to develop interventions to address the specific needs of this population. Studies evaluating the impact of motor interventions among adolescents with DCD are limited.

AIM

The study evaluated the efficacy of two activity-based motor interventions in female adolescents with DCD.

METHODS AND PROCEDURES

Forty-three female participants (Mean±SD: 14.3±1.1years) were identified as having DCD using the DSM-5 criteria. They were randomly assigned to either Task-oriented Functional Training (TFT) or Wii training. Both groups received 45min training per week for 14 weeks. Outcome measures included isometric muscular strength, motor proficiency, functional performance and participation in activities of daily living (ADL).

OUTCOMES AND RESULTS

At the conclusion of the intervention, the two groups had significant improvement in muscular strength, motor proficiency, running and agility, predilection for physical activity and generalized self-efficacy. However, there was no difference in outcomes for the two interventions.

CONCLUSIONS AND IMPLICATIONS

The findings highlight the potential benefits of activity-based motor interventions in reducing impairments, improving functional performance, and enhancing participation. These results support previous findings on the efficacy of task-oriented interventions and demonstrate the value of these approaches at all levels of functioning.

Learning better by repetition or variation? Is transfer at odds with task specific training?

Objective

Transfer of motor skills is the ultimate goal of motor training in rehabilitation practice. In children with Developmental Coordination Disorder (DCD), very little is known about how skills are transferred from training situations to real life contexts. In this study we examined the influence of two types of practice on transfer of motor skills acquired in a virtual reality (VR) environment.

Method

One hundred and eleven children with DCD and their typically developing (TD) peers, aged 6–10 years (M = 8.0 SD = 1.0) were randomly assigned to either variable (n = 56) or repetitive practice (n = 55). Participants in the repetitive practice played the same exergame (ski slalom) twice weekly for 20 minutes, over a period of 5 weeks, while those in the variable group played 10 different games. Motor skills such as balance tasks (hopping), running and agility tasks, ball skills and functional activities were evaluated before and after 5 weeks of training.

Results

ANOVA repeated measures indicated that both DCD and TD children demonstrated transfer effects to real life skills with identical and non-identical elements at exactly the same rate, irrespective of the type of practice they were assigned to.

Conclusion

Based on these findings, we conclude that motor skills acquired in the VR environment, transfers to real world contexts in similar proportions for both TD and DCD children. The type of practice adopted does not seem to influence children’s ability to transfer skills acquired in an exergame to life situations but the number of identical elements does.

Variable training does not lead to better motor learning compared to repetitive training in children with and without DCD when exposed to active video games

BACKGROUND

Little is known about the influence of practice schedules on motor learning and skills transfer in children with and without developmental coordination disorder (DCD). Understanding how practice schedules affect motor learning is necessary for motor skills development and rehabilitation.

AIMS

The study investigated whether active video games (exergames) training delivered under variable practice led to better learning and transfer than repetitive practice.

METHODS AND PROCEDURES

111 children aged 6-10 years (M=8.0, SD=1.0) with no active exergaming experience were randomized to receive exergames training delivered under variable (Variable Game Group (VGG), n=56) or repetitive practice schedule (Repetitive Game Group (RGG), n=55). Half the participants were identified as DCD using the DSM-5 criteria, while the rest were typically developing (TD), age-matched children. Both groups participated in two 20min sessions per week for 5 weeks.

OUTCOMES AND RESULTS

Both participant groups (TD and DCD) improved equally well on game performance. There was no significant difference in positive transfer to balance tasks between practice schedules (Repetitive and Variable) and participant groups (TD and DCD).

CONCLUSIONS AND IMPLICATIONS

Children with and without DCD learn balance skills quite well when exposed to exergames. Gains in learning and transfer are similar regardless of the form of practice schedule employed.

WHAT THIS PAPER ADDS

This is the first paper to compare the effect of practice schedules on learning in children with DCD and those with typical development. No differences in motor learning were found between repetitive and variable practice schedules. When children with and without DCD spend the same amount of time on exergames, they do not show any differences in acquisition of motor skills. Transfer of motor skills is similar in children with and without DCD regardless of differences in practice schedules.

Performance on Functional Strength Measurement and Muscle Power Sprint Test confirm poor anaerobic capacity in children with Developmental Coordination Disorder

BACKGROUND

There is little and conflicting information about anaerobic performance and functional strength in children with Developmental Coordination Disorder (DCD).

AIMS

To investigate anaerobic capacity and functional strength in children with a clinical diagnosis of DCD (clin-DCD) and if differences were larger in older (age 7-10 years) compared to younger children (age 4-6 years). Furthermore to determine the percentage of children with clin-DCD that scored <15th percentile on the norm-referenced Functional Strength Measurement.

METHOD

A clin-DCD group (36 boys, 11 girls, mean age: 7y 1mo, SD=2y 1mo) and a typically developing group (TD) (57 boys, 53 girls, mean age: 7y 5mo, SD=1y 10mo) were compared on Muscle Power Sprint Test (MPST) and Functional Strength Measurement (FSM).

RESULTS

Children with clin-DCD performed poorer on the MPST and FSM, especially on the muscle endurance items of the FSM. The differences were larger in the older children compared to the younger on the cluster muscle endurance and the FSM total score. Over 50% of clin-DCD group scored <15th percentile on the FSM.

INTERPRETATION

Differences between children with clin-DCD and TD children are even more pronounced in the older children, especially when tested on items requiring fast repetitive movements.

Physical and Mental Health of Children with Developmental Coordination Disorder

Developmental coordination disorder (DCD) is a neurodevelopmental condition characterized by poor motor proficiency that interferes with an individual’s activities of daily living. These problems in motor coordination are prevalent despite children’s intelligence levels. Common symptoms include marked delays in achieving motor milestones and clumsiness, typically associated with poor balance, coordination, and especially handwriting skills. Currently, DCD is said to impact about 2–7% of school-age children. More importantly, DCD is considered to be one of the major health problems among school-aged children worldwide, with unique consequences to physical and mental health. Because these children and adolescents often experience difficulties participating in typical childhood activities (e.g., riding a bike), they tend to be more sedentary, more overweight/obese, at a higher risk for coronary vascular disease, and have lower cardiorespiratory and physical fitness than their typically developing peers. From another perspective, the motor difficulties have also been linked to an increased risk for mental health issues, such as higher anxiety and depression. The understanding of the health consequences associated with DCD offers practical applications for the understanding of the mechanisms and intervention protocols that can improve the consequences of this condition. In this review, I will explore such consequences and provide evidence for the implementation of interventions that focus on improving physical and mental health in this population.

Manual function outcome measures in children with developmental coordination disorder (DCD): Systematic review

This study systematically reviewed the clinical and psychometric properties of manual function outcome measures for children with developmental coordination disorder (DCD) aged 3-18 years. Three electronic databases were searched to identify manual function tools at the ICF-CY body function, activity and participation level used in children with DCD. Study selection and data extraction was conducted by two blind assessors according to the CanChild Outcome Measures Rating Form. Nineteen clinical tests (seven fine hand use tools and 12 handwriting measures), three naturalistic observations and six questionnaires were identified. The fine-motor subdomain of the Movement Assessment Battery for Children, the Bruininks-Oseretsky Test of Motor Proficiency-2 and the Functional Strength Measurement, with adequate reliability and validity properties, might be useful for manual function capacity assessment. The Systematic Detection of Writing Problems (SOS) and the Detailed Assessment of Speed of Handwriting (DASH) could be adopted for handwriting assessment, respectively from 6 and 9 years old. Naturalistic observations and questionnaires, whose psychometric properties have been investigated into limited extent, offer an assessment of the daily performances. This review shows that a combination of different tools is needed for a comprehensive assessment of manual function in children with DCD including the three levels of the ICF-CY. Further investigation of psychometric properties of those tools in children with DCD is warranted. Tests validated in other populations should be explored for their applicability for assessing manual function in children with DCD.

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

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

Reliability and Structural and Construct Validity of the Functional Strength Measurement in Children Aged 4 to 10 Years

BACKGROUND

Adequate muscle strength, power, and endurance are important in children's daily activities and sports. Various instruments have been developed for the assessment of muscle function; each measures different aspects. The Functional Strength Measurement (FSM) was developed to measure performance in activities in which strength is required.

OBJECTIVE

The study objective was to establish the test-retest reliability and structural and construct validity of the FSM.

DESIGN

A cross-sectional descriptive study was conducted.

METHODS

The performance of 474 children with typical development on the FSM was examined. Test-retest reliability (n=47) was calculated with the intraclass correlation coefficient (2.1A) for agreement. Structural validity was examined with exploratory factor analysis, and internal consistency was established with the Cronbach alpha. Construct validity was determined by calculating correlations between FSM scores and scores obtained with a handheld dynamometer (HHD) (n=252) (convergent validity) and between FSM scores and scores on the Movement Assessment Battery for Children-2 (MABC-2) (n=77) (discriminant validity).

RESULTS

The test-retest reliability of the FSM total score ranged from .91 to .94. The structural validity revealed one dimension, containing all 8 FSM items. The Cronbach alpha was .74. The convergent validity with the HHD ranged from .42 to .74. The discriminant validity with MABC-2 items revealed correlations that were generally lower than .39, and most of the correlations were not significant. Exploratory factor analysis of a combined data set (FSM, HHD, and MABC-2; n=77) revealed 2 factors: muscle strength/power and muscle endurance with an agility component.

LIMITATIONS

Discriminant validity was measured only in children aged 4 to 6 years.

CONCLUSIONS

The FSM, a norm-referenced test for measuring functional strength in children aged 4 to 10 years, has good test-retest reliability and good construct validity.

The effect of a motor skills training program in the improvement of practiced and non-practiced tasks performance in children with developmental coordination disorder (DCD)

The purpose of the present study was to examine the effect of a group-based task oriented skills training program on motor and physical ability for children with DCD. It was also investigated if there was an effect on fine motor and handwriting tasks that were not specifically practiced during the training program. Forty-one children aged 6-10years took part in this study. Children were assigned to three groups: an experimental training group consisting of 14 children with DCD, a control non-training group consisted of 13 children with DCD and a control non-training group consisting of 14 typically developed children. The measurements included were, the Movement Assessment Battery for Children (MABC), the Modified Agility Test (MAT), the Triple Hop Distance (THD), the 5 Jump-test (5JT) and the Handwriting Performance Test. All measures were administered pre and post an 8-week training program. The results showed that 10 children of the DCD training-group improved their performance in MABC test, attaining a score above the 15th percentile after their participation in the training program. DCD training-group showed a significant improvement on all cluster scores (manual dexterity (t (13)=5.3, p<.001), ball skills (t (13)=2.73, p<.05) and balance (t (13)=5.13, p<.001). Significant performance improvements were also found in MAT, THD, 5JT (t (13)=-4.55; p<.01), handwriting quality (t (12)=-2.73; p<.05) and speed (t (12)=-4.2; p<.01) after the training program. In conclusion, improvement in both practiced and non-practiced skills, in the training program, may reflect improvement in motor skill but also transfer to other skills.

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.

Is Treating Motor Problems in DCD Just a Matter of Practice and More Practice?

Developmental coordination disorder (DCD) is often called a motor learning deficit. The question addressed in this paper is whether improvement of motor skills is just a matter of mere practice. Without any kind of intervention, children with DCD do not improve their motor skills generally, whereas they do improve after task-oriented intervention. Merely offering children the opportunity to practice motor skills, for instance by playing active video games, did lead to improved motor performance according to recent research findings, but to a lesser extent than task-oriented intervention. We argue that children with DCD lack the required motor problem-solving skills necessary to further improve their performance. Explicit motor teaching with an emphasis on developing these problem-solving skills is a necessary ingredient of intervention in DCD, leveraging the effectiveness of intervention above that of mere practicing.