Visuomotor adaptation, internal modelling, and compensatory movements in children with developmental coordination disorder.

BACKGROUND: Developmental coordination disorder (DCD) is one of the most prevalent developmental disorders in school-aged children. The mechanisms and etiology underlying DCD remain somewhat unclear. Altered visuomotor adaptation and internal model deficits are discussed in the literature. AIMS: The study aimed to investigate visuomotor adaptation and internal modelling to determine whether and to what extent visuomotor learning might be impaired in children with DCD compared to typically developing children (TD). Further, possible compensatory movements during visuomotor learning were explored. METHODS AND PROCEDURES: Participants were 12 children with DCD (age 12.4 ± 1.8, four female) and 18 age-matched TD (12.3 ± 1.8, five female). Visuomotor learning was measured with the Motor task manager. Compensatory movements were parameterized by spatial and temporal variables. OUTCOMES AND RESULTS: Despite no differences in visuomotor adaptation or internal modelling, significant main effects for group were found in parameters representing movement accuracy, motor speed, and movement variability between DCD and TD. CONCLUSIONS AND IMPLICATIONS: Children with DCD showed comparable performances in visuomotor adaptation and internal modelling to TD. However, movement variability was increased, whereas movement accuracy and motor speed were reduced, suggesting decreased motor acuity in children with DCD.

Secular trends in motor performance in Swiss children and adolescents from 1983 to 2018.

Introduction: Environmental changes, including globalization, urbanization, social and cultural changes in society, and exposure to modern digital technology undoubtedly have an impact on children's activity and lifestyle behavior. In fact, marked reductions in children's physical activity levels have been reported over the years and sedentary behavior has increased around the world. The question arises whether these environmental changes had an impact on general motor performance in children and adolescents. The study aimed to investigate secular trends of motor performance in Swiss children and adolescents, aged between 7 and 18 years, over a period of 35 years from 1983 to 2018. Methods: Longitudinal data on the five motor components of the Zurich Neuromotor Assessment (ZNA) - pure motor (PM), fine motor (FM), dynamic balance (DB), static balance (SB), and contralateral associated movements (CAM) - were pooled with cross-sectional data on PM and FM from eight ZNA studies between 1983 and 2018. Regression models were used to estimate the effect of the year of birth on motor performance and body mass index (BMI) measurements. Models were adjusted for age, sex, and socioeconomic status. Results: The secular trend estimates in standard deviation scores (SDS) per 10 years were - 0.06 [-0.33; 0.22, 95% Confidence Interval] for PM, -0.11 [-0.41; 0.20] for FM, -0.38 [-0.66; -0.09] for DB (-0.42 when controlled for BMI), -0.21 [-0.47; 0.06] for SB, and - 0.01 [-0.32; 0.31] for CAM. The mean change in BMI data was positive with 0.30 SDS [0.07; 0.53] over 10 years. Discussion: Despite substantial societal changes since the 1980s, motor performance has remained relatively stable across generations. No secular trend was found in FM, PM, SB, and CAM over a period of 35 years. A secular trend in DB was present independent of the secular trend in body mass index.

Integration of Speed and Quality in Measuring Graphomotor Skills: The Zurich Graphomotor Test.

IMPORTANCE: In educational settings, children are under pressure to finish their work successfully within required time frames. Existing tools for assessing graphomotor skills measure either quality or speed of performance, and the speed-accuracy trade-off (SAT) in such tools has never been investigated. OBJECTIVE: We aimed to evaluate a newly developed tool for measuring graphomotor skills, the Zurich Graphomotor Test (ZGT), that assesses both speed and quality of performance. We also explored whether graphomotor tests are affected by the SAT and, if so, the effects it has on graphomotor test results. DESIGN: Cross-sectional study. SETTING: Educational institutions in Switzerland. PARTICIPANTS: Children, adolescents, and young adults (N = 547) ages 4-22 yr (50.3% female). OUTCOMES AND MEASURES: Graphomotor performance was measured with the ZGT and the Developmental Test of Visual Perception, Second Edition (DVTP-2). Standard deviation scores were used to quantify performance. We combined ZGT speed and quality measurements into a performance score adjusted for age and sex. RESULTS: ZGT results indicated a marked developmental trend in graphomotor performance; older children were faster than younger children. Girls showed higher overall performance than boys. The pattern of making more mistakes when being faster and making fewer mistakes when being slower was observed for both graphomotor tests, regardless of time pressure, indicating that the SAT affected the children's scores on both tests. CONCLUSIONS AND RELEVANCE: SAT is influential in graphomotor assessment. The ZGT captures this trade-off by combining accuracy and speed measurements into one score that provides a realistic assessment of graphomotor skills. What This Article Adds: The newly developed ZGT provides occupational therapy practitioners with more precise information on graphomotor skills in children, adolescents, and young adults than currently available tools.

Impact of body mass index and socio-economic status on motor development in children and adolescents.

This study assessed the impact of body mass index (BMI) and socioeconomic status (SES) on the Zurich Neuromotor Assessment, second version (ZNA-2), a battery of tests of motor development in typically developing children between 3 and 18 years of age. BMI measurements and international socio-economic index data were taken from the normative sample of the ZNA-2 for 321 children (158 boys, 163 girls) with a median age of 9.3 years. The age- and gender-adjusted motor performance of these children was quantified and grouped into five components: fine, pure, and gross motor tasks, static balance, and contralateral associated movements. A total score was also calculated. The associations of BMI and SES with the motor scores contribute to less than 5.1% of the total variance.Conclusion: The ZNA-2 for motor development is suitable for measuring motor abilities' development as it is largely independent of the BMI of the child and the SES of the family. What is Known: • Typical motor development, as measured with the Zurich Neuromotor Assessment, second edition (ZNA-2), is strongly dependent on age and gender. • The ZNA-2 focusses on motor performance, motor quality and simple motor skills. What is New: • Higher socio-economic status (SES) is associated with slightly better motor performance as measured by the ZNA-2 total score. • In the ZNA-2 less than 5.1% of the variability in motor performance is attributable to the combined effect of body mass index and SES.

A quick and qualitative assessment of gross motor development in preschool children.

There is a need for a quick, qualitative, reliable, and easy tool to assess gross motor development for practitioners. The aim of this cross-sectional study is to present the Zurich Neuromotor Assessment-Q (ZNA-Q), which assesses static and dynamic balance in children between 3 and 6 years of age in less than 5 min. A total of 216 children (103 boys; 113 girls; median age 4 years, 4 months; interquartile range 1 year, 3 months) were enrolled from day-care centers, kindergartens, and schools, and were tested with 5 different gross motor tasks: standing on one leg, tandem stance, hopping on one leg, walking on a straight line, and jumping sideways. All ordinal measures (consisting of qualitative measures and scales) featured a marked developmental trend and substantial inter-individual variability. Test-retest reliability was assessed on 37 children. It varied from .17 for tandem stance to .43 for jumping sideways for the individual tasks, and it was .41 and .67 for the static and dynamic balance components, respectively. For the whole ZNA-Q, test-retest reliability was .7.Conclusion: Ordinal scales enable practitioners to gather data on children's gross motor development in a fast and uncomplicated way. It offers the practitioner with an instrument for the exploration of the current developmental motor status of the child. What is Known: • Measurement of gross motor skills in the transitional period between motor mile stones and quantitative assessments is difficult. • Assessment of gross motor skills is relatively easy. What is New: • Supplementary and quick gross motor test battery for children for practitioners. • Normative values of five gross motor skills measured with ordinal scales.

Neuromotor development in children. Part 4: new norms from 3 to 18 years.

AIM: The aim of this cross-sectional study was to provide normative data for motor proficiency (motor performance and contralateral associated movements [CAMs]) in typically developing children between 3 years and 18 years of age using an updated version of the Zurich Neuromotor Assessment (ZNA-2). METHOD: Six-hundred and sixteen typically developing children between 3 years and 18 years of age were enrolled from day-care centres, kindergartens, and schools, and were tested using the ZNA-2 with improved items of the original battery. Motor proficiency was assessed on five components (fine motor tasks, pure motor tasks, static balance, dynamic balance, and CAMs) as a function of age and sex to determine centile curves for each task. Intraobserver, interobserver, and test-retest reliabilities were evaluated. RESULTS: Most ZNA-2 tasks featured a marked developmental trend and substantial interindividual variability. Test-retest reliability was generally high (e.g. static balance 0.67; CAMs 0.81; and total scores 0.84). INTERPRETATION: The ZNA-2 is a reliable and updated test instrument to measure motor proficiency in children from 3 to 18 years with improved properties for assessing motor performance. It allows continuous measurement without changing items for the entire age range; this feature of the ZNA-2 is unique and makes the instrument suitable for clinical purposes. The reduction of CAMs scoring simplifies the clinical procedure and increases its reliability. WHAT THIS PAPER ADDS: The Zurich Neuromotor Assessment, Second Edition (ZNA-2) provides new norms for motor proficiency in children between 3 years and 18 years. High reliabilities suggest that the revised test battery is a useful tool for assessing neuromotor development. Integration of a 'not able to perform' category makes the ZNA-2 suitable for clinical purposes.

Comparison between the Movement ABC-2 and the Zurich Neuromotor Assessment in Preschool Children.

An established test instrument for the assessment of motor performance in children between 3 and 16 years is the Movement Assessment Battery for Children - Second Edition (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 for children below five years for the purpose of convergent validity. Forty-seven children (26 boys, 21 girls) between three and five years of age were assessed using the M-ABC-2 and the ZNA3-5. Rank correlations between scores of different test components were calculated. Only low-to-moderate correlations were observed when separate components of these tests were compared (.31 to .68, p < .05), especially when involving the associated movements from the ZNA3-5 (-.05 to -.13, p > .05). However, the correlation between summary scores of the two tests was .77 (p < .001), and it increased to .84 when associated movements were excluded, which was comparable in magnitude to the test-retest reliability of the M-ABC-2, supporting convergent validity between the two tests. Although the ZNA3-5 and M-ABC-2 measure different aspects of motor behavior, the two instruments may thus measure essentially the same construct.