Influence of methylphenidate on motor performance and attention in children with developmental coordination disorder and attention deficit hyperactive disorder

Individuals with attention deficit hyperactive disorder (ADHD) often have coexisting developmental coordination disorder (DCD). The positive therapeutic effect of methylphenidate on ADHD symptoms is well documented, but its effects on motor coordination are less studied. We assessed the influence of methylphenidate on motor performance in children with comorbid DCD and ADHD. Participants were 30 children (24 boys) aged 5.10–12.7 years diagnosed with both DCD and ADHD. Conners’ Parent Rating Scale was used to reaffirm ADHD diagnosis and the Developmental Coordination Disorder Questionnaire was used to diagnose DCD. The Movement Assessment Battery for Children-2 and the online continuous performance test were administrated to all participants twice, with and without methylphenidate. The tests were administered on two separate days in a blind design. Motor performance and attention scores were significantly better with methylphenidate than without it (p < 0.001 for improvement in the Movement Assessment Battery for Children-2 and p < 0.006 for the online continuous performance test scores).The findings suggest that methylphenidate improves both attention and motor coordination in children with coexisting DCD and ADHD. More research is needed to disentangle the causality of the improvement effect and whether improvement in motor coordination is directly affected by methylphenidate or mediated by improvement in attention.     

Behavioral comparisons in Autism Spectrum Disorder and Developmental Coordination Disorder: A systematic literature review

BackgroundAutism Spectrum Disorder (ASD) and Developmental Coordination Disorder (DCD) are developmental disorders that, since the DSM-5, can be diagnosed as co-occurring conditions. While some recent studies suggest that ASD and DCD have similar traits, others show clear behavioral distinctions between the two conditions. By gathering all studies that included (1) an ASD group and a DCD group, (2) an ASD + DCD group and a DCD group, or (3) ASD, ASD + DCD, and DCD groups, we aimed to identify similarities and differences in behaviors between the two disorders.MethodWe used a systematic search of PubMed (1946 –), Scopus (1970 –), PsycINFO (via EBSCO, 1600 –), CINAHL (via EBSCO, 1937 –), SportDiscus (via EBSCO, 1985 –), and WorldCat (via FirstSearch) in addition to reference list and author name searching PubMed, Scopus, PsycINFO, CINAHL, SportDiscus, and WorldCat to identify original studies that met the following criteria: (1) an ASD group and a DCD group, (2) an ASD + DCD group and a DCD group, or (3) ASD, ASD + DCD, and DCD groups.ResultsFrom the 1598 articles screened, 11 were included in the qualitative analysis. The articles included reported more differences than similarities in individuals with ASD and DCD, with clear distinctions for working memory ability, gestural performance, grip selection, and cortical thickness. Only two studies reported similarities in face processing abilities and perceived competence, and the interventional studies showed group similarities in behavior improvement, such as intelligence and attention.ConclusionsBased on the articles reviewed, we conclude that while DCD and ASD share some behavioral symptoms, the symptom profiles of each disorder are unique and separable. We recommend that the evaluation of potential DCD in individuals with ASD be performed systematically and thoroughly, so as to distinguish this co-occurring condition from sensorimotor symptoms associated with ASD.     

Do children with ASD have difficulty handwriting under time pressure?

BackgroundChildren with autism spectrum disorder (ASD) often experience significant handwriting impairment, however the influence of time pressure on overall performance is unclear. The aim of the current study was to characterise the handwriting profile of children with ASD across both non-speeded and speeded conditions, with particular focus given to spacing difficulties and handwriting errors. A further aim was to explore the relationships between handwriting and both intellectual and motor skills under different task conditions.MethodBoys with ASD (n = 23) and matched controls (n = 20) aged 8–12 years completed a modified version of the speed subtest of the Handwriting Performance Test, which allowed for both an ecologically valid and relatively simple motoric task. Participants wrote a simple phrase (cat and dog) five times in each condition.ResultsNo significant group differences were identified for handwriting errors or spacing between words in either condition, however the ASD group demonstrated greater variability relative to controls, particularly in the speeded condition. Significant negative associations were identified between motor proficiency and handwriting errors in the non-speeded condition.ConclusionsWhile motor processes are shown to have a significant role in overall handwriting proficiency, it appears that motor ability may influence the handwriting process to different degrees, depending on the nature of the task employed. A lack of group differences with respect to handwriting errors and spacing between words may suggest that children with ASD have the ability to compensate for underlying motor impairment when completing a well-practiced writing task.     

Implicit and explicit motor learning: Application to children with Autism Spectrum Disorder (ASD)

Aims and objectivesThis study aims to determine whether children with Autism Spectrum Disorder (ASD) are capable of learning a motor skill both implicitly and explicitly.MethodsIn the present study, 30 boys with ASD, aged 7–11 with IQ average of 81.2, were compared with 32 typical IQ- and age-matched boys on their performance on a serial reaction time task (SRTT). Children were grouped by ASD and typical children and by implicit and explicit learning groups for the SRTT.ResultsImplicit motor learning occurred in both children with ASD (p = .02) and typical children (p = .01). There were no significant differences between groups (p = .39). However, explicit motor learning was only observed in typical children (p = .01) not children with ASD (p = .40). There was a significant difference between groups for explicit learning (p = .01).DiscussionThe results of our study showed that implicit motor learning is not affected in children with ASD. Implications for implicit and explicit learning are applied to the CO-OP approach of motor learning with children with ASD.     

The effects of balance training intervention on postural control of children with autism spectrum disorder: Role of sensory information

PurposeThe aim of this study was to investigate the effect of balance training intervention in children with autism spectrum disorder (ASD), and to explore the relative role of the sensory systems in such kids.MethodologyWe recruited 20 school children (IQ > 80) diagnosed with ASD, and categorized them in two groups; a 10-member training group (average age: 7.70 ± 1.05) and a 10-member control group (average age: 7.90 ± 1.10). Thus, following a six-week-long balance training intervention in four conditions of bipedal upright stance [compliant (Foam) vs. non-compliant (Hard) with eyes-open (EO) vs. eyes-closed (EC)], we examined measures such as mean velocity (V), anteroposterior (AP) and mediolateral (ML) axis displacement, and compared the results to those calculated prior to the initiation of the intervention using MANOVA test.ResultsThis study showed that the balance training program efficiently improved the postural control in ASD suffering children, and that removing the visual and plantar proprioceptive information led to increased sway in both groups. The training group performed significantly better than the control group in all conditions.ConclusionIt is thus concludable that children suffering from ASD can benefit from such balance training programs to improve their balance and postural control.     

Gross motor skills are related to postural stability and age in children with autism spectrum disorder

Motor skill and postural stability deficits are commonly reported for children with autism spectrum disorder (ASD), however the relationship between these variables is not well established. We explored the relationship between motor skills, postural stability, restricted and repetitive patterns of behavior, diagnosis, age, and sex. Children (11 with and 11 without ASD), 5–12 years of age, participated in the study. The Test of Gross Motor Development-3 (TGMD-3) was used to assess fundamental motor skills. Postural sway was measured on a force plate during quiet standing on a solid and compliant surface. Center of pressure was calculated and used to compute sway area. Linear regression analysis showed that sway area on a solid surface, age, and diagnosis were significant predictors of motor skill performance (R² = .854). Severity of ASD, as assessed by the Repetitive Behavior Scale-Revised (RBS-R), was not predictive of motor skills. Children with ASD exhibited deficits in postural stability compared to children without ASD. Postural stability appears to influence the ability of children to perform gross motor skills. However, the RBS-R does not seem to be a useful tool for identifying those children with ASD who exhibit the greatest deficits in motor skills.     

The relationship of motor skills and adaptive behavior skills in young children with autism spectrum disorders

ObjectiveTo determine the relationship of motor skills and adaptive behavior skills in young children with autism.DesignA multiple regression analysis tested the relationship of motor skills on the adaptive behavior composite, daily living, adaptive social and adaptive communicative skills holding constant age, non-verbal problem solving, and calibrated autism severity.SettingMajority of the data collected took place in an autism clinic.ParticipantsA cohort of 233 young children with ASD (n = 172), PDD-NOS (n = 22) and non-ASD (developmental delay, n = 39) between the ages of 14–49 months were recruited from early intervention studies and clinical referrals. Children with non-ASD (developmental delay) were included in this study to provide a range of scores indicted through calibrated autism severity.InterventionsNot applicable.Main outcome measuresThe primary outcome measures in this study were adaptive behavior skills.ResultsFine motor skills significantly predicted all adaptive behavior skills (p < 0.01). Gross motor skills were predictive of daily living skills (p < 0.05). Children with weaker motor skills displayed greater deficits in adaptive behavior skills.ConclusionsThe fine and gross motor skills are significantly related to adaptive behavior skills in young children with autism spectrum disorder. There is more to focus on and new avenues to explore in the realm of discovering how to implement early intervention and rehabilitation for young children with autism and motor skills need to be a part of the discussion.     

Physical fitness in children with Developmental Coordination Disorder: Measurement matters

Children with Developmental Coordination Disorder (DCD) experience considerable difficulties coordinating and controlling their body movements during functional motor tasks. Thus, it is not surprising that children with DCD do not perform well on tests of physical fitness. The aim of this study was to determine whether deficits in motor coordination influence the ability of children with DCD to perform adequately on physical fitness tests. A case–control study design was used to compare the performance of children with DCD (n = 70, 36 boys, mean age = 8y 1mo) and Typically Developing (TD) children (n = 70, 35 boys, mean age = 7y 9mo) on measures of isometric strength (hand-held dynamometry), functional strength, i.e. explosive power and muscular endurance (Functional Strength Measurement), aerobic capacity (20 m Shuttle Run Test) and anaerobic muscle capacity, i.e. muscle power (Muscle Power Sprint Test). Results show that children with DCD were able to generate similar isometric forces compared to TD children in isometric break tests, but were significantly weaker in three-point grip strength. Performance on functional strength items requiring more isolated explosive movement of the upper extremities, showed no significant difference between groups while items requiring muscle endurance (repetitions in 30 s) and items requiring whole body explosive movement were all significantly different. Aerobic capacity was lower for children with DCD whereas anaerobic performance during the sprint test was not. Our findings suggest that poor physical fitness performance in children with DCD may be partly due to poor timing and coordination of repetitive movements.     

Assessment of gait characteristics and orthotic management in children with Developmental Coordination Disorder: Preliminary findings to inform multidisciplinary care

Developmental Coordination Disorder (DCD) is a neurodevelopmental disorder characterised by impaired motor co-ordination and awkward gait. Despite self-reported findings of pes planus and joint hypermobility in children with DCD, there is little objective evidence regarding the clinical management of the foot in children with DCD. The aims of this research were to report clinical findings of foot posture and lower limb hypermobility in children with DCD and to evaluate the impact of foot orthoses on spatio-temporal gait parameters. Children with DCD were recruited into the study. Participants were randomly assigned to an intervention group who received foot orthoses at the start of their rehabilitation programme or to a second group who received foot orthoses at the end of their intervention programme. Foot posture was assessed with the Foot Posture Index and lower limb hypermobility assessed with the Lower Limb Assessment Score. The effect of foot orthoses was evaluated through assessment of spatio-temporal gait characteristics at baseline and post-rehabilitation programme. Fourteen children were recruited (mdn age 7.5 years) with nine children assigned to the group receiving orthoses early (mdn age 8 years) and five children assigned to the post-rehabilitation orthoses group (mdn age 6.5 years). A pes planus foot posture (FPI score = 8) and lower limb hypermobility (LLAS score = 11) were observed. Changes in spatio-temporal gait parameters failed to reach significance (p > .012) following orthotic invention but demonstrated a trend towards a decreased cadence and increased double support duration. Despite non-significant findings this work offers preliminary support for podiatric intervention in the rehabilitation of children with DCD. Further work is required to understand the biomechanics of gait in children with DCD and appreciate the role of podiatry as a component of multidisciplinary care.     

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.     

Visual-motor integration,visual perception,and fine motor coordination in a population of children with high levels of Fetal Alcohol Spectrum Disorder

BackgroundVisual-motor integration (VMI) skills are essential for successful academic performance, but to date no studies have assessed these skills in a population-based cohort of Australian Aboriginal children who, like many children in other remote, disadvantaged communities, consistently underperform academically. Furthermore, many children in remote areas of Australia have prenatal alcohol exposure (PAE) and Fetal Alcohol Spectrum Disorder (FASD), which are often associated with VMI deficits.MethodsVMI, visual perception, and fine motor coordination were assessed using The Beery-Buktenica Developmental Test of Visual-Motor Integration, including its associated subtests of Visual Perception and Fine Motor Coordination, in a cohort of predominantly Australian Aboriginal children (7.5–9.6 years, n = 108) in remote Western Australia to explore whether PAE adversely affected test performance. Cohort results were reported, and comparisons made between children i) without PAE; ii) with PAE (no FASD); and iii) FASD. The prevalence of moderate (≤16th percentile) and severe (≤2nd percentile) impairment was established.ResultsMean VMI scores were ‘below average’ (M = 87.8 ± 9.6), and visual perception scores were ‘average’ (M = 97.6 ± 12.5), with no differences between groups. Few children had severe VMI impairment (1.9%), but moderate impairment rates were high (47.2%). Children with FASD had significantly lower fine motor coordination scores and higher moderate impairment rates (M = 87.9 ± 12.5; 66.7%) than children without PAE (M = 95.1 ± 10.7; 23.3%) and PAE (no FASD) (M = 96.1 ± 10.9; 15.4%).ConclusionsAboriginal children living in remote Western Australia have poor VMI skills regardless of PAE or FASD. Children with FASD additionally had fine motor coordination problems. VMI and fine motor coordination should be assessed in children with PAE, and included in FASD diagnostic assessments.     

Spatial and temporal analysis of postural control in children with high functioning Autism Spectrum Disorder

BackgroundChildren with autism spectrum disorders (ASD) have poor postural stability. The objective of our study was to explore further postural capabilities in ASD children by measuring spatial as well as temporal displacement of the center of pressure using wavelet analysis.MethodThirty children with ASD (12.1 ± 2.9 years) and 30 sex-, age- and IQ-matched typically developing children participated in the study. We recorded postural control using Multitest, also called Balance Quest, Equilibre from Framiral^® in three viewing conditions (eyes open, eyes closed and with perturbed vision) and in two postural conditions (stable and unstable).ResultsOur results show that children with ASD displayed a deficit in postural stability in comparison with typically developing children, especially when sensory inputs are not all available.ConclusionSuch poor postural control in children with ASD could be due to both an impairment in using sensorial inputs appropriately and a deficit in the ability to compensate for sensorial changes.     

Similarities and dissimilarities between the Movement ABC-2 and the Zurich Neuromotor Assessment in children with suspected developmental coordination disorder

An established tool for the assessment of motor performance in children with developmental coordination disorder (DCD) is the Movement-ABC-2 (M-ABC-2). The Zurich Neuromotor Assessment (ZNA) is also widely used for the evaluation of children's motor performance, but has not been compared with the M-ABC-2. Fifty-one children (39 males) between 5 and 7 years of age with suspected DCD were assessed using the M-ABC-2 and the ZNA. Rank correlations between scores of different test components were calculated. The structure of the tests was explored using canonical-correlation analysis. The correlation between total scores of the two motor tests was reasonable (0.66; p < 0.001). However, ZNA scores were generally lower than those of M-ABC-2, due to poor performance in the fine motor adaptive component and increased contralateral associated movements (CAM). The canonical-correlation analysis revealed that ZNA measures components like pure motor skills and CAM that are not represented in the M-ABC-2. Furthermore, there was also no equivalent for the aiming and catching items of the M-ABC-2 in ZNA. The two tests measure different motor characteristics in children with suspected DCD and, thus, can be used complementary for the diagnosis of the disorder.     

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

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

Sensorimotor function in preschool-aged children with expressive language disorder

AimThe aim of the study was to evaluate functional motor performance and haptic object recognition in 5-year-old children with mild expressive language disorder (ELD) in comparison with age- and gender-matched healthy children.MethodsThe subjects were classified by speech-language pathologist using The Reynell Developmental Language Scales III and Boehm Test of Basic Concepts: Preschool as children with mild ELD (n = 29, incl. 23 boys and 6 girls) and children with typical language development as controls (n = 29, incl. 23 boys and 6 girls). The children were examined for manual dexterity, ball skills, static and dynamic balance by Movement-ABC, haptic object recognition (HOR), hand-grip strength (HGS) and vertical jumping performance.ResultsChildren with mild ELD demonstrated significantly higher scores (i.e., inferior performance) in all subtests of M-ABC (all p values <0.05), in haptic object recognition (p < 0.01) and vertical jumping height (p < 0.05) compared to controls. However, no statistically significant differences (p > 0.05) emerged from HGS. Boys with mild ELD demonstrated higher results in impairment score (p < 0.001), ball skills (p < 0.01) and balance (p < 0.01) of M-ABC, as well as in HOR (p < 0.05). Girls with mild ELD showed higher impairment score (p < 0.05) with lower percentile (p < 0.05) in M-ABC, indicating inferior motor performance, and lower HGS for the non-dominant hand (p < 0.05). Seven out of 29 (24.1%) children with mild ELD had definite or borderline motor difficulties, while only one child in control group (3.4%) demonstrated borderline motor difficulties.ConclusionsChildren with mild expressive language disorder do not perform as well as controls in tests of functional motor skills, but their results in tests demanding maximal muscle force generation are in level with typically developing children. Boys and girls with mild ELD demonstrated higher impairment scores in M-ABC, indicating the need to follow their overall development more closely.     

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

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

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

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

Slowed muscle force production and sensory organization deficits contribute to altered postural control strategies in children with developmental coordination disorder

This study aimed to (1) compare the postural control strategies, sensory organization of balance control, and lower limb muscle performance of children with and without developmental coordination disorder (DCD) and (2) determine the association between postural control strategies, sensory organization parameters and knee muscle performance indices among children with DCD. Fifty-eight DCD-affected children and 46 typically developing children participated in the study. Postural control strategies and sensory organization were evaluated with the sensory organization test (SOT). Knee muscle strength and time to produce maximum muscle torque (at 180°/s) were assessed using an isokinetic machine. Analysis of variance was used to compare the outcome variables between groups, and multiple regression analysis was used to examine the relationships between postural control strategies, sensory organization parameters, and isokinetic indices in children with DCD. The DCD group had significantly lower strategy scores (SOT conditions 5 and 6), lower visual and vestibular ratios, and took a longer time to reach peak torque in the knee flexor muscles than the control group (p > 0.05). After accounting for age, sex, and body mass index, the vestibular ratio explained 35.8% of the variance in the strategy score of SOT condition 5 (p < 0.05). Moreover, the visual ratio, vestibular ratio, and time to peak torque of the knee flexors were all significant predictors (p < 0.05) of the strategy score during SOT condition 6, accounting for 14, 19.7, and 19.8% of its variance, respectively. The children with DCD demonstrated deficits in postural control strategy, sensory organization and prolonged duration of muscle force development. Slowed knee muscle force production combined with poor visual and vestibular functioning may result in greater use of hip strategy by children with DCD in sensory challenging environments.     

Development and initial validation of the Preschool Imitation and Praxis Scale (PIPS)

The goal of this study was to develop and subsequently evaluate the internal construct and criterion-related validity of the Preschool Imitation and Praxis Scale (PIPS). Different task characteristics were selected considered to be important as unravelled in research in apraxic adults to tap a broad range of possible imitation mechanisms. Participants included 498 children without disabilities (1–4.9 years) and 47 children with autism spectrum disorders (ASD) (1.9–4.5 years). Exploratory factor analysis disclosed 4 dimensions in the scale, labelled: goal directed versus non-goal directed procedural imitation and single versus sequential bodily imitation. Internal consistency for the PIPS scale (α = .97) and subscales was high (α ranged from .79 to .96). In both samples, the PIPS scale score was strongly related to age (r = .78, respectively r = .56). Significant relationships between the PIPS score and mental, language, motor ages in the ASD sample supported criterion-related validity (r ranged from .59 to .74). The PIPS appears to have fundamentally sound psychometric characteristics, although more research is needed.     

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

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