DCD: Research update 2016

New research published in January / February 2016

Wilmut K, Du W, Barnett AL. Gait patterns in children with Developmental Coordination Disorder. Exp Brain Res. 2016 Feb 15. [Epub ahead of print] PubMed
PMID: 26879769.

Previous research has shown that adults with Developmental Coordination Disorder (DCD) show increased variability of foot placement measures and movement of the centre of mass (CoM) while walking. The current study considered the gait patterns of young and older children with DCD. Fourteen young children with DCD (7-12 years), 15 older children with DCD (12-17 years) and 29 age- and gender-matched typically developing children took part. Children were asked to walk up and down a flat 10-m-long pathway for 1 min, while the movement of their feet and trunk was recorded using motion analysis. The gait pattern of children with DCD was characterised by wider steps, elevated variability in the time spent in double support and stride time and greater medio-lateral velocity and acceleration compared to their peers. An elevated variability in medio-lateral acceleration was also seen in the young but not the older children with DCD. In addition, the young children showed a greater variability in velocity and acceleration in all three directions compared to the older children. The data suggest that the high incidence of trips and falls seen in children with DCD may be due to differences in the control of the CoM.

Fong SS, Guo X, Liu KP, Ki WY, Louie LH, Chung RC, Macfarlane DJ. Task-Specific Balance Training Improves the Sensory Organisation of Balance
Control in Children with Developmental Coordination Disorder: A Randomised Controlled Trial.
Sci Rep. 2016 Feb 11;6:20945. doi: 10.1038/srep20945. PubMed
PMID: 26864309; PubMed Central PMCID: PMC4750073.

Sensory organisation of balance control is compromised in children with developmental coordination disorder(DCD). A randomised controlled trial involving 88 children with DCD was conducted to evaluate the efficacy of a task-specific balance training (functional-movement training, FMT) programme in improving balance deficits in a DCD population. The DCD participants were randomly assigned to either a FMT group or a control group. The FMT group received two training sessions/ week for 3 months. Measurements of the participants' sensory organisation (somatosensory, vestibular and visual ratios), balance and motor proficiency (Movement Assessment Battery for Children, MABC scores) and center of pressure sway velocity (Unilateral Stance Test, UST scores) were taken at baseline, immediately after FMT and 3 months after FMT. The FMT group showed greater improvements than the controls in somatosensory ratio at 3 and 6 months (all P < 0.001), but the within-group changes were not significant (P > 0.05). The results of both the MABC and the UST also indicated that the balance performance of the FMT group was significantly better than that of the control group at 3 and 6 months (all P < 0.05). Task-specific balance training was found to marginally improve the somatosensory function and somewhat improve the balance performance of children with DCD.

Adams IL, Lust JM, Wilson PH, Steenbergen B. Testing predictive control of movement in children with developmental coordination disorder using converging
Br J Psychol. 2016 Feb 9. doi: 10.1111/bjop.12183. [Epub ahead of print] PubMed PMID: 26861617.

Recent systematic reviews (Wilson et al., 2013, Dev. Med. Child Neurol., 55, 217; Adams et al., 2014, Neurosci. Biobehav. Rev., 47C, 225) suggest that a common underlying problem in developmentalcoordination disorder (DCD) is the internal modelling deficit. The study presented here is the first to test this hypothesis using a within-subject design, assessing motor imagery, action planning, and rapid online control (ROC) in a sample of children screened rigorously for DCD. Participants were 66 children; 33 children (26 boys and seven girls) aged 6-11 years in the DCD group and 33 controls (gender and age matched). Motor imagery was assessed with the hand rotation task (HRT), action planning with an end-state comfort effect test, and ROC with the double-step pointing task. Results showed that children with DCD were slower and less accurate than controls in the HRT. Reduced forward planning for comfortable end-state was also shown in DCD. Finally, no group differences were found on the ROC task. Collectively, children with DCD manifest deficits in the internal modelling of movements, but this varies under different task constraints, particularly those related to movement complexity.

Zamani MH, Fatemi R, Soroushmoghadam K. Comparing the Effects of Self-Controlled and Examiner-Controlled Feedback on Learning in Children With
Developmental Coordination Disorder
Iran J Psychiatry Behav Sci. 2015 Dec;9(4):e2422. doi: 10.17795/ijpbs-2422. Epub 2015 Dec 23. PubMed PMID:
26834805; PubMed Central PMCID: PMC4733309.

BACKGROUND: Feedback can improve task learning in children with developmental coordination disorder(DCD). However, the frequency and type of feedback may play different role in learning and needs to more investigations.

OBJECTIVES: The aim of this study was to evaluate the acquisition and retention of new feedback skills in children with DCD under different frequency of self-control and control examiner feedback.

MATERIALS AND METHODS: In this quasi-experimental study with pretest-posttest design, participants based on their retention were divided into four feedback groups: self-controlled feedback groups with frequencies of 50% and75%, experimenter controls with frequencies of 50% and 75%. The study sample consisted of 24 boys with DCD aged between 9 to 11 years old in Ahvaz City, Iran. Then subjects practiced 30 throwing (6 blocks of 5 attempts) in eighth session. Acquisition test immediately after the last training session, and then the retention test were taken. Data were analyzed using the paired t-test, ANOVA and Tukey tests.

RESULTS: The results showed no significant difference between groups in the acquisition phase (P > 0.05). However,in the retention session, group of self-control showed better performance than the control tester group (P < 0.05).

CONCLUSIONS: Based on the current findings, self-control feedback with high frequency leads to more learning in DCD children. The results of this study can be used in rehabilitation programs to improve performance and learning in children with DCD.

Adams IL, Ferguson GD, Lust JM, Steenbergen B, Smits-Engelsman BC. Action planning and position sense in children with Developmental Coordination Disorder. Hum Mov Sci. 2016 Apr;46:196-208. doi: 10.1016/j.humov.2016.01.006. Epub 2016 Jan 18. PubMed PMID: 26796420.

The present study examined action planning and position sense in children with Developmental CoordinationDisorder (DCD). Participants performed two action planning tasks, the sword task and the bar grasping task, and an active elbow matching task to examine position sense. Thirty children were included in the DCD group (aged 6-10years) and age-matched to 90 controls. The DCD group had a MABC-2 total score ⩽5th percentile, the control group a total score ⩾25th percentile. Results from the sword-task showed that children with DCD planned less for end-state comfort. On the bar grasping task no significant differences in planning for end-state comfort between the DCD and control group were found. There was also no significant difference in the position sense error between the groups. The present study shows that children with DCD plan less for end-state comfort, but that this result is task-dependent and becomes apparent when more precision is needed at the end of the task. In that respect, the sword-task appeared to be a more sensitive task to assess action planning abilities, than the bar grasping task. The action planning deficit in children with DCD cannot be explained by an impaired position sense during active movements.

Suzuki R, Tanaka A, Matsui T, Gunji T, Tohyama J, Nairita A, Nanba E, Ohno K. Niemann-Pick Disease Type C Presenting as a Developmental Coordination Disorder with Bullying by Peers in a School-Age Child. Case Rep Pediatr. 2015;2015:807591. doi: 10.1155/2015/807591. Epub 2015 Dec 16. PubMed PMID: 26788393; PubMed Central PMCID: PMC4695637.

Niemann-Pick disease type C (NPC) is a rare progressive neurodegenerative disorder, often with onset after normal early childhood development. Juvenile onset NPC patients slowly develop cerebellar symptoms and cognitive impairment and often experience difficulties at school. However, these problems may be overlooked due to the unpublicized nature of NPC, given that it is a rare metabolic disorder. In this report, we present an 11-year-old male NPC patient, who suffered from clumsiness and difficulties in attention and academic and social skills. His symptoms were initially considered to be due to developmental coordination disorder (DCD) coexisting with bullying by peers. DCD is a type of neurodevelopmental disorder defined according to DSM-IV and is characterized by clumsiness that interferes with academic achievement and social integration not due to other general medical conditions. However, a detailed investigation of the patient suggested that the problems could be attributed to the onset of NPC. Clinicians should keep neurodegenerative disorders as differential diagnosis of children with multiple school problems.

Zwicker JG. Developmental Coordination Disorder and Its Consequences. Adapt Phys Activ Q. 2016 Jan;33(1):97-98. PubMed PMID: 26785503.

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

van den Heuvel M, Jansen DE, Reijneveld SA, Flapper BC, Smits-Engelsman BC.Identification of emotional and behavioral problems by teachers in children with developmental coordination disorder in the school community. Res Dev Disabil. 2016 Apr-May;51-52:40-8. doi: 10.1016/j.ridd.2016.01.008. Epub 2016 Jan 15.PubMed PMID: 26780353.

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

Farmer M, Echenne B, Bentourkia M. Study of clinical characteristics in young subjects with Developmental Coordination Disorder. Brain Dev. 2016 Jan 4. pii:
S0387-7604(15)00278-8. doi: 10.1016/j.braindev.2015.12.010. [Epub ahead of print] PubMed PMID: 26763621.

BACKGROUND: Developmental Coordination Disorder (DCD) is a chronic neurological disorder observed in children. DCD is characterized by slowness in activities and motor impairment that affects the children's daily living and academic achievements, and later their professional and social behavior. Our aim in this work was to report characteristics frequencies in a group of children with DCD and to propose a subtyping of DCD characteristics.

METHODS: Thirty three clinical DCD characteristics, the mostly reported in the literature, were assessed in 129 patients, boys and girls aged from 4 years to 18 years, and their sub-typing was proposed. The statistical analyses were carried out with the Chi square, the t-test and the correlation for the statistical differences, and with the Ward clustering method for sub-typing.

RESULTS: We found that there were 3.17 boys for one girl, all patients were characterized as slow, 47% were left-handers or ambidextrous, 36% and 26% had orofacial and verbal dyspraxia, respectively, 83% were found anxious, and 84% were described as being clumsy.

CONCLUSIONS: It appears from these results that a child with DCD expresses more than a single difficulty. Three subtypes emerged from the statistical analysis in this study: (1) clumsiness and other characteristics except language difficulties; (2) self-esteem and peer relation without clumsiness and language difficulties; (3) language difficulties and orofacial dyspraxia.

Adams IL, Steenbergen B, Lust JM, Smits-Engelsman BC. Motor imagery training for children with developmental coordination disorder - study protocol for a randomized controlled trial. BMC Neurol. 2016 Jan 12;16(1):5. doi:10.1186/s12883-016-0530-6. PubMed PMID: 26758026; PubMed Central PMCID: PMC4710999.

BACKGROUND: Previous studies have shown that the predictive control of movements is impaired in children with Developmental Coordination Disorder (DCD), most likely due to a deficit in the internal modeling of movements. Motor imagery paradigms have been used to test this internal modeling deficit. The aim of the present study is to examine whether a training focused on the mental imagery of motor skills, can help to improve the motor abilities of children with DCD.

METHODS/DESIGN: A pre-post design will be used to examine the motor performance, motor imagery and motor planning abilities before and after a training of 9 weeks. Two groups will be included in this study (1) one receiving motor imagery (MI) training focused on the forward modeling of purposive actions, (2) one receiving Cognitive Orientation to daily Occupational Performance (CO-OP) training focused on identifying effective cognitive strategies that will increase motor competence. MI training will be given with the use of instruction videos of the motor skill that will be trained. Both groups will participate in 9 individual sessions of 45 min (once a week) with a paediatric physical or occupational therapist, added with homework sessions. Inclusion criteria are: (1) aged 7-12 years, (2) meeting the DSM-V criteria for DCD (motor performance substantially low (score on the m-ABC ≤ 16th percentile) and motor problems that interfere with daily life (DCDQ, and request for help at a paediatric physical or occupational therapist)). Exclusion criteria are IQ < 70 and other medical conditions causing the motor impairment.

DISCUSSION: The results of this study will help to make treatment protocols for children with DCD more evidence-based. This study will increase our knowledge about the efficacy of both the MI training and CO-OP training, and both children with DCD and therapists will benefit from this knowledge.

Biotteau M, Albaret JM, Lelong S, Chaix Y. Neuropsychological status of French children with developmental dyslexia and/or developmental coordination
disorder: Are both necessarily worse than one?
Child Neuropsychol. 2016 Jan 4:1-20. [Epub ahead of print] PubMed PMID: 26729293.

Developmental dyslexia (DD) and developmental coordination disorder (DCD) co-occur frequently, raising the underlying question of shared etiological bases. We investigated the cognitive profile of children with DD, children with DCD, and children with the dual association (DD + DCD) to determine the inherent characteristics of each disorder and explore the possible additional impact of co-morbidity on intellectual, attentional, and psychosocial functioning. The participants were 8- to 12-year-olds (20 DD, 22 DCD, and 23 DD + DCD). Cognitive abilities were assessed by the Wechsler Intelligence Scale for Children - Fourth Edition (WISC-IV) and the Continuous Performance Test - Second Edition (CPT-II) and behavioral impairments were evaluated by the Child Behavior Checklist (CBCL). No differences were found between the three groups on attention testing (CPT-II) or psychosocial characteristics (CBCL), but a higher percentage of DD + DCD children had pathological scores on psychosocial scales. Significant between-group differences were observed on Processing Speed Index scores and the block design and symbol search subtests, where DD children fared better than DCD children. No significant differences were evident between the co-morbid vs. the pure groups. Our results clearly show significant differences between children with DD only and children with DCD only. In particular, visuo-spatial disabilities and heterogeneity of intellectual profile seem to be good markers of DCD. However, it should be noted that despite these distinct and separate characteristics, a common cognitive profile (weaknesses and strengths) is likely shared by both neurodevelopmental disorders. Surprisingly, concerning co-morbidity, DD + DCD association is not associated with a decrease in intellectual or attentional capacities.

Farhat F, Hsairi I, Baati H, Smits-Engelsman BC, Masmoudi K, Mchirgui R, Triki C, Moalla W. 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). Hum Mov Sci. 2016 Apr;46:10-22. doi:
10.1016/j.humov.2015.12.001. Epub 2015 Dec 17. PubMed PMID: 26703915.

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.

King-Dowling S, Rodriguez MC, Missiuna C, Cairney J. Validity of the Ages and Stages Questionnaire to detect risk of Developmental Coordination Disorder in
. Child Care Health Dev. 2016 Mar;42(2):188-94. doi: 10.1111/cch.12314. Epub 2015 Dec 20. PubMed PMID: 26686096.

BACKGROUND:A reliable and valid screening tool for detecting children at risk for DevelopmentalCoordination Disorder (DCD) is needed. The purpose of this study was to evaluate the ability of the Ages and Stages Questionnaire-Third Edition (ASQ-3) motor scales to detect children at risk for DCD in a community-based sample of children aged 3.5-5.5 years.

METHODS:One hundred and sixty parent-child pairs were recruited from community-based organizations. Children were eligible if they spoke English and had no known physical impairments. Eligible parents were asked to fill out the ASQ-3, following which their child's fine motor and gross motor proficiency was assessed using the Movement Assessment Battery for Children - Second Edition (MABC-2). DCD risk was defined as those children scoring at or below the 16th percentile on the MABC-2. Sensitivity and specificity of the fine and gross motor areas of the ASQ-3 were examined and referenced against the DCD risk classification.

RESULTS: The ASQ-3 total motor score correlated moderately with overall standard score on the MABC-2 (r = 0.41; p < 0.001). Regardless of the ASQ-3 cut-off used, sensitivities of the ASQ-3 fine motor or gross motor scale to detect DCD risk were low at 21-47%, whereas specificities were high at 89-96%.

CONCLUSION: Early identification of motor skill delays is important in order to intervene and hopefully prevent the associated negative health consequences. However, because of the low sensitivity of the ASQ-3 motor scales, these results suggest that the ASQ-3 is not an appropriate screening tool to identify children at risk for DCD in the preschool population.

Fong SS, Ng SS, Chung LM, Ki WY, Chow LP, Macfarlane DJ. Direction-specific impairment of stability limits and falls in children with developmental
coordination disorder: Implications for rehabilitation
. Gait Posture. 2016 Jan;43:60-4. doi: 10.1016/j.gaitpost.2015.10.026. Epub 2015 Nov 10. PubMed PMID: 

Limit of stability (LOS) is an important yet under-examined postural control ability in children withdevelopmental coordination disorder (DCD). This study aimed to (1) compare the LOS and fall frequencies of children with and without DCD, and (2) explore the relationships between LOS parameters and falls in the DCD population. Thirty primary school-aged children with DCD and twenty age- and sex-matched typically-developing children participated in the study. Postural control ability, specifically LOS in standing, was evaluated using the LOS test. Reaction time, movement velocity, maximum excursion, end point excursion, and directional control were then calculated. Self-reported fall incidents in the previous week were also documented. Multivariate analysis of variance results revealed that children with DCD had shorter LOS maximum excursion in the backward direction compared to the control group (p=0.003). This was associated with a higher number of falls in daily life (rho=-0.556, p=0.001). No significant between-groups differences were found in other LOS-derived outcomes (p>0.05). Children with DCD had direction-specific postural control impairment, specifically, diminished LOS in the backward direction. This is related to their falls in daily life. Therefore, improving LOS should be factored into rehabilitation treatment for children with DCD.

15: Howie EK, Campbell AC, Straker LM. An active video game intervention does not improve physical activity and sedentary time of children at-risk for
developmental coordination disorder: a crossover randomized trial.
Child Care Health Dev. 2016 Mar;42(2):253-60. doi: 10.1111/cch.12305. Epub 2015 Dec 9.
PubMed PMID: 26648488.

BACKGROUND: Children with developmental coordination disorder (DCD) are highly inactive and sedentary. The purpose of this study was to assess the impact of a home-based active video game intervention on objectively measured physical activity and sedentary behaviour in children at risk for DCD.

METHODS: In a crossover randomized clinical trial, 21 children (mean age 11.0, SD 1.0; n = 11 girls) in Perth, Western Australia participated in two 16-week periods: no active video games (AVGs) control period and AVGs intervention period. Two active input consoles were provided to participants along with a selection of non-violent AVGs for participants to play at home. Participants wore accelerometers at baseline and following each period to determine minutes of sedentary, light, moderate and vigorous times in addition to self-reported types of activities in a diary. Linear mixed models, adjusted for the order of periods, compared physical activity and sedentary time during the last week of each period.

RESULTS: There were no significant differences between the intervention and control periods in time spent in sedentary (decrease of -1.0 min/day during the intervention period, 95%CI -12.1, 10.1), light (increase of 2.2 min/day, 95%CI -8.8, 13.2), moderate (decrease of 0.7 min/day, 95%CI -4.6, 3.3) or vigorous (decrease of -0.6 min/day, 95%CI -1.6, 0.4).

CONCLUSIONS: Among children at risk for DCD, participating in this AVG intervention did not improve objectively measured physical activity and sedentary time.

16: Farhat F, Masmoudi K, Hsairi I, Smits-Engelsman BC, Mchirgui R, Triki C,Moalla W. b. Appl Physiol Nutr Metab. 2015 Dec;40(12):1269-78. doi: 10.1139/apnm-2015-0154. Epub 2015 Aug 19. PubMed PMID: 26579947.

Interventions based on everyday motor skills have been developed to be effective in children withdevelopmental coordination disorder (DCD). The purpose of the present study was to examine the effects of motor skill training on exercise tolerance and cardiorespiratory fitness in children with DCD. Children were assigned to 3 groups: an experimental training group comprising 14 children with DCD, a control nontraining group comprising 13 children with DCD, and a control nontraining group comprising 14 typically developed children. All participants were tested twice with an interval of 8-weeks on a cardiopulmonary exercise test, pulmonary function testing, and a 6-min walk test. After the training program the maximal power output was significantly increased for DCD group at anaerobic threshold (p < 0.05) and at peak level (maximal oxygen uptake, p < 0.001). Improvement in power output was more pronounced at the anaerobic threshold (t (13) = -5.21, p < 0.001) than at the maximal intensity (maximal oxygen uptake, t (13) = -3.08, p < 0.01) in the DCD training group. Children with DCD that participated in the training program improved their walking distance (t (13) = -9.08, p < 0.001), had a higher maximum heart rate (t (13) = -3.41, p < 0.01), and reduced perceived exertion (t (13) = 2.75, p < 0.05). The DCD nontraining group and the typically developed group did not change on any of the measures. In conclusion, training delayed reaching the anaerobic threshold and improved aerobic endurance and exercise tolerance in children with DCD.

17: Caçola P, Ibana M, Ricard M, Gabbard C. Children with developmental coordination disorder demonstrate a spatial mismatch when estimating coincident-timing ability with tools. Res Dev Disabil. 2016 Jan;48:124-31. doi: 10.1016/j.ridd.2015.10.021. Epub 2015 Nov 8. PubMed PMID: 26555384.

Coincident timing or interception ability can be defined as the capacity to precisely time sensory input and motor output. This study compared accuracy of typically developing (TD) children and those withDevelopmental Coordination Disorder (DCD) on a task involving estimation of coincident timing with their arm and various tool lengths. Forty-eight (48) participants performed two experiments where they imagined intercepting a target moving toward (Experiment 1) and target moving away (Experiment 2) from them in 5 conditions with their arm and tool lengths: arm, 10, 20, 30, and 40cm. In Experiment 1, the DCD group overestimated interception points approximately twice as much as the TD group, and both groups overestimated consistently regardless of the tool used. Results for Experiment 2 revealed that those with DCD underestimated about three times as much as the TD group, with the exception of when no tool was used. Overall, these results indicate that children with DCD are less accurate with estimation of coincident-timing; which might in part explain their difficulties with common motor activities such as catching a ball or striking a baseball pitch.

Debrabant J, Vingerhoets G, Van Waelvelde H, Leemans A, Taymans T, Caeyenberghs K. Brain Connectomics of Visual-Motor Deficits in Children with
Developmental Coordination Disorder
. J Pediatr. 2016 Feb;169:21-27.e2. doi: 10.1016/j.jpeds.2015.09.069. Epub 2015 Oct 31. PubMed PMID: 26526363.

OBJECTIVE: To extend preliminary findings on associated white matter deficits and structural connectivity in children with developmental coordination disorder (DCD).
STUDY DESIGN:Diffusion magnetic resonance imaging-based tractography was used to identify abnormal microstructural properties of specific sensorimotor white matter tracts in 21 children with DCD between 8 and 10 years of age and 20 age- and sex-matched typically developing controls. Graph theoretical analyses were applied to evaluate whole brain connectomics. Associations were also calculated between the tractography/connectome results and visual-motor performance, as measured with the Beery-BuktenicaDevelopmental Test of Visual Motor Integration.
RESULTS: Significant positive correlations were obtained between visual-motor trace scores and fractional anisotropy (FA) in the retrolenticular limb of the internal capsule within the group with DCD. Moreover, lower FA in sensorimotor tracts and altered structural connectivity were observed for children with DCD. Compared with controls, subjects with DCD showed decreases in clustering coefficient, and global and local efficiency, suggesting weaker structural network segregation and integration. The degree of decreased global efficiency was significantly associated with poor visual-motor tracing outcomes, above and beyond FA reductions. Specifically, nodal efficiency at the cerebellar lobule VI and right parietal superior gyrus were found significant predictors to discriminate between children with DCD and those with typical development.
CONCLUSIONS: Specific white matter alterations and network topology features associate with visual-motor deficits and DCD diagnosis indicating the clinical potential of diffusion magnetic resonance imaging-based metrics for diagnosing DCD.

Reynolds JE, Licari MK, Billington J, Chen Y, Aziz-Zadeh L, Werner J, Winsor AM, Bynevelt M. Mirror neuron activation in children with developmental
coordination disorder: A functional MRI study.
Int J Dev Neurosci. 2015 Dec;47(Pt B):309-19. doi: 10.1016/j.ijdevneu.2015.10.003. Epub 2015 Oct 30. PubMed PMID:

The aim of this study was to reveal cortical areas that may contribute to the movement difficulties seen in children with Developmental Coordination Disorder (DCD). Specifically, we hypothesized that there may be a deficit in the mirror neuron system (MNS), a neural system that responds to both performed and observed actions. Using functional MRI, 14 boys with DCD (x¯=10.08 years±1.31, range=7.83-11.58 years) and 12 typically developing controls (x¯=10.10 years±1.15, range=8.33-12.00 years) were scanned observing, executing and imitating a finger sequencing task using their right hand. Cortical activations of mirror neuron regions, including posterior inferior frontal gyrus (IFG), ventral premotor cortex, anterior inferior parietal lobule and superior temporal sulcus were examined. Children with DCD had decreased cortical activation mirror neuron related regions, including the precentral gyrus and IFG, as well as in the posterior cingulate and precuneus complex when observing the sequencing task. Region of interest analysis revealed lower activation in the pars opercularis, a primary MNS region, during imitation in the DCD group compared to controls. These findings provide some preliminary evidence to support a possible MNS dysfunction in children with DCD.

Hua J, Gu G, Zhu Q, Wo D, Liu M, Liu JQ, Mao J, Duan T. The reliability and validity of the Developmental Coordination Disorder Questionnaire'07 for children
aged 4-6 years in mainland China.
Res Dev Disabil. 2015 Dec;47:405-15. doi: 10.1016/j.ridd.2015.10.006. Epub 2015 Oct 27. PubMed PMID: 26513741.

An effective population-based screening tool is needed to identify possible cases of DevelopmentalCoordination Disorder (DCD) among preschool children in mainland China. We examined the psychometric properties of the DCD questionnaire'07 (DCDQ'07) in Chinese children aged 4-6. A total of 3316 children from 10 nursery schools were involved in the study. Internal consistency and test-retest reliability of the DCDQ'07 were estimated using Cronbach's alpha, item-total correlation and intraclass correlation co-efficient (ICC). The construct validity was evaluated using the exploratory and confirmatory factor analysis. Receiver operating characteristic (ROC) analysis was used to measure the accuracy of the DCDQ'07. The results showed that both internal consistency (Cronbach's alpha value of all items were above 0.85) and test-retest reliability (ICCs of 13 items and subscales were above 0.9) were excellent. Confirmatory factor analysis showed that each goodness-of-fit indices of the 3-factor model was above 0.9, indicating a satisfactory fit of the data to the model. Area under the ROC curve was comparatively small (0.641). With the exception of construct validity in younger children (4 years old) and discriminative validity, the Chinese version of the DCDQ'07 achieves satisfactory reliability and construct validity in mainland China. Nevertheless, the questionnaire should be not used in younger children, and further studies are needed to explore the use of Little DCD-Q in Chinese preschool children.