Search

Background: Individuals with developmental coordination disorder (DCD) experience motor skill and executive function (EF) difficulties that challenge their daily activities., Aim/objective: This systematic review aims to provide an in-depth analysis of the relationships between motor skills and EFs in studies among individuals with DCD., Material and Methods: We conducted a systematic search of eight electronic databases for articles (published 1994-2021) reporting on quantitative studies that estimated relationships between motor skills and EFs when assessing children, adolescents and adults with DCD. Motor skills and EFs were assessed via reliable and validated assessment tools. Two reviewers independently screened the articles. We evaluated the quality of the selected articles according to EPHPP guidelines and the methodological quality of the assessments from these studies using the COSMIN checklist and reported results following the PRISMA-P checklist. This systematic review was registered in PROSPERO (CRD42019124578)., Results: A total of 30,808 articles were screened. Eleven articles met the inclusion criteria and were reviewed. Findings from nine studies demonstrated weak to strong correlations between aspects of motor skills and EFs., Conclusions and Significance: Limited evidence supports the relationships between motor skills and EFs among individuals with DCD. Occupational therapists should consider the possibility of this relationship and give more consideration to these components when planning intervention for individuals with DCD.

Although fine particulate matter (PM 2.5 ) is a neurotoxicant, little is known about whether early-life PM 2.5 exposure is associated with an increased risk of developmental coordination disorder (DCD). We conducted a cohort study of 109 731 children aged 3-5 years from 551 county-level cities in China between April 2018 and December 2019. Residential PM 2.5 exposure was estimated using a hybrid satellite-based exposure model. Children's motor performance was assessed using the Little DCD Questionnaire (LDCDQ). Linear mixed-effect models and generalized linear mixed models with a binomial distribution were used to examine the associations of PM 2.5 exposure with LDCDQ scores and risk of DCD, respectively. Both prenatal and postnatal exposure to a higher level of PM 2.5 was significantly associated with reduced total LDCDQ score, and the impacts were evident on subscales of control during movement and general coordination function but not fine motor function. For example, an interquartile range increase in PM 2.5 exposure in ages 0-3 was associated with a 0.19 (95% confidence interval [CI]: 0.05, 0.33) decrement in the total score. Additionally, higher PM 2.5 exposure was associated with increased risk of DCD, and the adjusted odds ratios were 1.06 (95% CI: 1.01, 1.10) and 1.06 (95% CI: 1.01, 1.13) for each interquartile range increase in PM 2.5 exposure during the first trimester and the first 3 years, respectively. Children who were from rural areas, had neonatal intensive care unit admission, or were exclusively breastfed for less than 6 months appeared to be more susceptible to PM 2.5 exposure than their counterparts. Our findings provide robust evidence that early-life PM 2.5 exposure contributes to an elevated risk of DCD., Competing Interests: The authors declare no competing interests., (© 2022 The Author(s).)

Background: Both sleep quality and quantity are essential for normal brain development throughout childhood; however, the association between preterm birth and sleep problems in preschoolers is not yet clear, and the effects of gestational age across the full range from preterm to post-term have not been examined. Our study investigated the sleep outcomes of children born at very-preterm (<31 weeks), moderate-preterm (32-33 weeks), late-preterm (34-36 weeks), early-term (37-38 weeks), full-term (39-40 weeks), late-term (41 weeks) and post-term (>41 weeks)., Methods: A national retrospective cohort study was conducted with 114,311 children aged 3-5 years old in China. Children's daily sleep hours and pediatric sleep disorders defined by the Children's Sleep Habits Questionnaire (CSHQ) were reported by parents. Linear regressions and logistic regression models were applied to examine gestational age at birth with the sleep outcomes of children., Results: Compared with full-term children, a significantly higher CSHQ score, and hence worse sleep, was observed in very-preterm (β = 1.827), moderate-preterm (β = 1.409), late-preterm (β = 0.832), early-term (β = 0.233) and post-term (β = 0.831) children, all p<0.001. The association of pediatric sleep disorder (i.e. CSHQ scores>41) was also seen in very-preterm (adjusted odds ratio [AOR] = 1.287 95% confidence interval [CI] (1.157, 1.433)), moderate-preterm (AOR = 1.249 95% CI (1.110, 1.405)), late-preterm (AOR = 1.111 95% CI (1.052, 1.174)) and post-term (AOR = 1.139 95% CI (1.061, 1.222)), all p<0.001. Shorter sleep duration was also found in very-preterm (β = -0.303), moderate-preterm (β = -0.282), late-preterm (β = -0.201), early-term (β = -0.068) and post-term (β = -0.110) compared with full-term children, all p<0.01. Preterm and post-term-born children had different sleep profiles as suggested by subscales of the CSHQ., Conclusions: Every degree of premature, early-term and post-term birth, compared to full-term, has an association with sleep disorders and shortened daily sleep duration. Preterm, early-term, and post-term should therefore all be monitored with an increased threat of sleep disorder that requires long-term monitoring for adverse sleep outcomes in preschoolers., (© 2022. The Author(s).)

Children with Developmental Coordination Disorder (DCD) have been shown to have different coordination patterns on some tasks compared to their typically developing peers. However, it is unclear whether these differences are driven by the fact that typically developing children tend to be more practiced at the task on which coordination is being measured. The current study used a novel pedalo task to measure coordination in order to eliminate any practice differences. Thirty children (8 years -16 years), 15 with DCD and 15 without were recruited for this study. Children pedalled along an 8 m line 20 times. Movement of the 7th Cervical Vertebra, shoulders, elbows, wrists, hips, knees, ankles and toes was recorded. In terms of outcome measures, pedalling speed was not different between the groups but the coefficient of variation of speed was higher in the children with DCD indicating a less smooth movement. Coordination was measured by calculating angles at the shoulder, elbow, hip, knee and ankle. A higher correlation coefficient (more tightly coupled movement) and a greater variation in joint angle was seen in the typically developing children for specific joint segments. The relationship between group and movement outcome (smoothness of movement) was mediated by inter-limb coordination variability. Therefore, the poor coordination and slower learning generally reported in children with DCD could be due to a slower or less optimal exploration of motor solutions., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Handwriting difficulties are frequently mentioned in descriptions of developmental coordination disorder (DCD). Recent studies have shown that children with DCD pause more and produce less text than typically developing (TD) peers. This temporal dysfluency indicates a lack of automaticity in handwriting production. One possible contributing factor is the accuracy and consistency of letter formation. The aim of this study was to gain a better understanding of handwriting dysfluency by examining the accuracy and consistency of letter production both within and across different writing tasks. A total of 28 children aged 8 to 15 years with DCD participated in the study with 28 TD age- and gender-matched control participants. They completed the alphabet writing and copy fast tasks from The Detailed Assessment of Speed of Handwriting on a digitizing writing tablet. The accuracy and consistency of letter production were examined. The DCD group had a higher percentage of errors within their letterforms than did the TD peers. Letter production was also less consistent between tasks. Children with DCD appear to have difficulties with the "allograph" (motor program) aspect of handwriting and may require explicit teaching of letter formation.

Movement, which draws on motor skills and executive functions for managing them, plays an important role in literacy learning (e.g., movement of mouth during oral reading and movement of hand and fingers during writing); but relatively little research has focused on movement skills in students with specific learning disabilities as the current study did. Parents completed normed Movement Assessment Battery for Children Checklist, 2nd edition (ABC-2), ratings and their children in grades 4 to 9 ( M = 11 years, 11 months; 94 boys, 61 girls) completed diagnostic assessment used to assign them to diagnostic groups: control typical language learning ( N = 42), dysgraphia (impaired handwriting) ( N = 29), dyslexia (impaired word decoding/reading and spelling) ( N = 65), or oral and written language learning disability (OWL LD) (impaired syntax in oral and written language) ( N = 19). The research aims were to (a) correlate the Movement ABC-2 parent ratings for Scale A Static/Predictable Environment (15 items) and Scale B Dynamic/Unpredictable Environment (15 items) with reading and writing achievement in total sample varying within and across different skills; and (b) compare each specific learning disability group with the control group on Movement ABC-2 parent ratings for Scale A, Scale B, and Scale C Movement-Related (Non-Motor Executive Functions, or Self-Efficacy, or Affect) (13 items). At least one Movement ABC-2 parent rating was correlated with each assessed literacy achievement skill. Each of three specific learning disability groups differed from the control group on two Scale A (static/predictable environment) items (fastens buttons and forms letters with pencil or pen) and on three Scale C items (distractibility, overactive, and underestimates own ability); but only OWL LD differed from control on Scale B (dynamic/unpredictable environment) items. Applications of findings to assessment and instruction for students ascertained for and diagnosed with persisting specific learning disabilities in literacy learning, and future research directions are discussed.

Background: Demands for the production of legible handwriting produced in a timely manner increase as children progress through school. Despite the considerable number of children faced with handwriting difficulties, there is no quick and practical tool to assess legibility in this population., Aim: The aim of this study was to develop the Handwriting Legibility Scale (HLS) and to establish the scale's reliability and validity., Methods: The HLS is a non-language dependent scale which assesses global legibility, based on five criteria applied to samples of 'free writing'. Content validity, inter-rater reliability and internal consistency were initially examined using scripts from 20 children aged 8-14 years. Construct validity was established by Principal Component Analysis (PCA) of data from 150 school children aged 9-14 years, with an additional examination of gender effects. Discriminant validity of the HLS score was examined in 29 children with Developmental Coordination Disorder (DCD) and 29 typically developing (TD) children., Results: The results indicated high internal consistency (α=0.92). The inter-rater reliability was acceptable but indicates the need to refine the scoring instructions. PCA of the five components revealed a one factor solution explaining 61% of the variance. In the discriminant analysis, 86.2% of the children with DCD and 89.7% of the TD children were correctly classified to their groups based on the total HLS score., Conclusions: The overall findings suggest that the HLS may be a useful tool to identify poor handwriting legibility, with application across different languages and writing scripts., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objective: Children with Developmental Coordination Disorder demonstrate a lack of automaticity in handwriting as measured by pauses during writing. Deficits in visual perception have been proposed in the literature as underlying mechanisms of handwriting difficulties in children with DCD. The aim of this study was to examine whether correlations exist between measures of visual perception and visual motor integration with measures of the handwriting product and process in children with DCD., Method: The performance of twenty-eight 8-14year-old children who met the DSM-5 criteria for DCD was compared with 28 typically developing (TD) age and gender-matched controls. The children completed the Developmental Test of Visual Motor Integration (VMI) and the Test of Visual Perceptual Skills (TVPS). Group comparisons were made, correlations were conducted between the visual perceptual measures and handwriting measures and the sensitivity and specificity examined., Results: The DCD group performed below the TD group on the VMI and TVPS. There were no significant correlations between the VMI or TVPS and any of the handwriting measures in the DCD group. In addition, both tests demonstrated low sensitivity., Conclusion: Clinicians should execute caution in using visual perceptual measures to inform them about handwriting skill in children with DCD., (Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.)

Spelling is a prerequisite to expressing vocabulary in writing. Research has shown that children with dyslexia are hesitant spellers when composing. This study aimed to determine whether the hesitant spelling of children with dyslexia, evidenced by frequent pausing, affects vocabulary choices when writing. A total of 31 children with dyslexia, mean age 9 years, were compared to typically developing groups of children: the first matched by age, the second by spelling ability. Oral vocabulary was measured and children completed a written and verbal compositional task. Lexical diversity comparisons were made across written and verbal compositions to highlight the constraint of having to select and spell words. A digital writing tablet recorded the writing. Children with dyslexia and the spelling-ability group made a high proportion of spelling errors and within-word pauses, and had a lower lexical diversity within their written compositions compared to their verbal compositions. The age-matched peers demonstrated the opposite pattern. Spelling ability and pausing predicted 53% of the variance in written lexical diversity of children with dyslexia, demonstrating the link between spelling and vocabulary when writing. Oral language skills had no effect. Lexical diversity correlated with written and verbal text quality for all groups. Practical implications are discussed and related to writing models., (© Hammill Institute on Disabilities 2014.)

Several studies have shown that Developmental Coordination Disorder (DCD) is a condition that continues beyond childhood. Although adults with DCD report difficulties with dynamic balance, as well as frequent tripping and bumping into objects, there have been no specific studies on walking in this population. Some previous work has focused on walking in children with DCD but variation in the tasks and measures used has led to inconsistent findings. The aim of the current study therefore was to examine the characteristics of level walking in adults with and without DCD. Fifteen adults with DCD and 15 typically developing (TD) controls walked barefoot at a natural pace up and down an 11 m walkway for one minute. Foot placement measures and velocity and acceleration of the body were recorded, as well as measures of movement variability. The adults with DCD showed similar gait patterns to the TD group in terms of step length, step width, double support time and stride time. The DCD group also showed similar velocity and acceleration to the TD group in the medio-lateral, anterior-posterior and vertical direction. However, the DCD group exhibited greater variability in all foot placement and some body movement measures. The finding that adults with DCD have a reduced ability to produce consistent movement patterns is discussed in relation to postural control limitations and compared to variability of walking measures found in elderly populations., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Although handwriting is typically taught during early childhood and keyboarding may not be taught explicitly, both may be relevant to writing development in the later grades. Thus, Study 1 investigated automatic production of the ordered alphabet from memory for manuscript (unjoined), cursive (joined), and keyboard letter modes (alphabet 15 sec) and their relationships with each other and spelling and composing in typically developing writers in grades 4 to 7 ( N = 113). Study 2 compared students with dysgraphia (impaired handwriting, n =27), dyslexia (impaired word spelling, n =40), or oral and written language learning disability (OWL LD) (impaired syntax composing, n =11) or controls without specific writing disabilities ( n =10) in grades 4 to 9 ( N =88) on the same alphabet 15 modes, manner of copying (best or fast), spelling, and sentence composing. In Study 1, sequential multilevel model regressions of predictor alphabet 15 letter production/selection modes on spelling and composition outcomes, measured annually from grade 4 to grade 7 (ages 9 to 13 years), showed that only the cursive mode uniquely , positively, and consistently predicted both spelling and composing in each grade. For composing, in grade 4 manuscript mode was positively predictive and in grades 5-7 keyboard selection was. In Study 2 all letter production modes correlated with each other and one's best and fast sentence copying, spelling, and timed sentence composing. The groups with specific writing disabilities differed from control group on alphabet 15 manuscript mode, copy fast, and timed sentence composing. The dysgraphia and dyslexia groups differed on copying sentences in one's best handwriting, with the dysgraphia group scoring lower. The educational and theoretical significance of the findings are discussed for multiple modes and manners of letter production/selection of the alphabet that support spelling and composing beyond the early grades in students with and without specific writing disabilities.

Difficulties with handwriting are reported as one of the main reasons for the referral of children with Developmental Coordination Disorder (DCD) to healthcare professionals. In a recent study we found that children with DCD produced less text than their typically developing (TD) peers and paused for 60% of a free-writing task. However, little is known about the nature of the pausing; whether they are long pauses possibly due to higher level processes of text generation or fatigue, or shorter pauses related to the movements between letters. This gap in the knowledge-base creates barriers to understanding the handwriting difficulties in children with DCD. The aim of this study was to characterise the pauses observed in the handwriting of English children with and without DCD. Twenty-eight 8-14 year-old children with a diagnosis of DCD participated in the study, with 28 TD age and gender matched controls. Participants completed the 10 min free-writing task from the Detailed Assessment of Speed of Handwriting (DASH) on a digitising writing tablet. The total overall percentage of pausing during the task was categorised into four pause time-frames, each derived from the literature on writing (250 ms to 2 s; 2-4 s; 4-10 s and >10 s). In addition, the location of the pauses was coded (within word/between word) to examine where the breakdown in the writing process occurred. The results indicated that the main group difference was driven by more pauses above 10 s in the DCD group. In addition, the DCD group paused more within words compared to TD peers, indicating a lack of automaticity in their handwriting. These findings may support the provision of additional time for children with DCD in written examinations. More importantly, they emphasise the need for intervention in children with DCD to promote the acquisition of efficient handwriting skill., (Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Current models of writing do not sufficiently address the complex relationship between the 2 transcription skills: spelling and handwriting. For children with dyslexia and beginning writers, it is conceivable that spelling ability will influence rate of handwriting production. Our aim in this study was to examine execution speed and temporal characteristics of handwriting when completing sentence-copying tasks that are free from composing demands and to determine the predictive value of spelling, pausing, and motor skill on handwriting production. Thirty-one children with dyslexia (Mage = 9 years 4 months) were compared with age-matched and spelling-ability matched children (Mage = 6 years 6 months). A digital writing tablet and Eye and Pen software were used to analyze handwriting. Children with dyslexia were able to execute handwriting at the same speed as the age-matched peers. However, they wrote less overall and paused more frequently while writing, especially within words. Combined spelling ability and within-word pausing accounted for over 76% of the variance in handwriting production of children with dyslexia, demonstrating that productivity relies on spelling capabilities. Motor skill did not significantly predict any additional variance in handwriting production. Reading ability predicted performance of the age-matched group, and pausing predicted performance for the spelling-ability group. The findings from the digital writing tablet highlight the interactive relationship between the transcription skills and how, if spelling is not fully automatized, it can constrain the rate of handwriting production. Practical implications are also addressed, emphasizing the need for more consideration to be given to what common handwriting tasks are assessing as a whole.

Handwriting difficulties are often included in descriptions of Developmental Coordination Disorder (DCD). They are cited as the most common reason for referral to health professionals following parent and teacher concerns about slow and untidy writing. The aim of this study was to compare handwriting performance in English children with and without DCD across a range of writing tasks, to gain a better understanding of the nature of 'slowness' so commonly reported. Twenty-eight 8-14 year-old children with a diagnosis of DCD participated in the study, with 28 typically developing age and gender matched controls. Participants completed the four handwriting tasks from the Detailed Assessment of Speed of Handwriting (DASH) and wrote their own name; all on a digitising writing tablet. The number of words written, speed of pen movements and the time spent pausing during the tasks were calculated. The findings confirmed what many professionals report, that children with DCD produce less text than their peers. However, this was not due to slow movement execution, but rather a higher percentage of time spent pausing. Discussion centres on the understanding of the pausing phenomenon in children with DCD and areas for further research., (Copyright © 2013 Elsevier Ltd. All rights reserved.)