H. Van Waelvelde

How common are motor problems in children with a developmental disorder: rule or exception?

BACKGROUND Few co-morbidity studies have been conducted since the Leeds Consensus Statement on developmental co-ordination disorder (DCD) in 2006. In this Statement, international cut-offs and inclusion criteria were agreed and consequently, the status of DCD changed. Furthermore, most existing co-morbidity studies are small clinical studies, rather than epidemiological studies, resulting in a broad range of co-morbidity rates. DCD has a higher incidence for boys in comparison with girls; questions arise if this preponderance remains the same in combination with other developmental disorders. Therefore, in this study we aimed to determine co-morbidity and gender differences of motor problems in children with a pervasive developmental disorder, a hyperkinetic disorder and/or a speech, language or learning disability. METHODS Profiles of 3608 children (mean age: 9 years 1 month) referred to rehabilitation centres for behavioural, developmental and sensorineural disorders were studied. RESULTS Motor problems were reported in one-fifth of the total sample. Co-morbidity of motor problems in specific disorders varied from almost one-fourth to more than one-third. The male/female ratio was significantly higher in children with motor problems and two or more other disorders, compared with children with motor problems and less than two other disorders. CONCLUSIONS This study indicates that co-morbidity of motor problems with other clinical disorders is not exceptional and developmental deviance is seldom specific to one domain. However, current co-morbidity studies tend to overestimate the number of children with motor problems. In addition, there may be different patterns of symptoms between the genders. These findings stress the importance of assessing motor skills in children with various developmental disorders.

Test–retest reliability of the assessment of postural stability in typically developing children and in hearing impaired children

The purpose of this study was to establish test-retest reliability of centre of pressure (COP) measurements obtained by an AccuGait portable forceplate (ACG), mean COG sway velocity measured by a Basic Balance Master (BBM) and clinical balance tests in children with and without balance difficulties. 49 typically developing children and 23 hearing impaired children, with a higher risk for stability problems, between 6 and 12 years of age participated. Each child performed the modified Clinical Test of Sensory Interaction on Balance (mCTSIB), Unilateral Stance (US) and Tandem Stance on ACG, mCTSIB and US on BBM and clinical balance tests: one-leg standing, balance beam walking and one-leg hopping. All subjects completed 2 test sessions on 2 different days in the same week assessed by the same examiner. Among COP measurements obtained by the ACG, mean sway velocity was the most reliable parameter with all ICCs higher than 0.72. The standard deviation (SD) of sway velocity, sway area, SD of anterior-posterior and SD of medio-lateral COP data showed moderate to excellent reliability with ICCs between 0.55 and 0.96 but some caution must be taken into account in some conditions. BBM is less reliable but clinical balance tests are as reliable as ACG. Hearing impaired children exhibited better relative reliability (ICC) and comparable absolute reliability (SEM) for most balance parameters compared to typically developing children. Reliable information regarding postural stability of typically developing children and hearing impaired children may be obtained utilizing COP measurements generated by an AccuGait system and clinical balance tests.

Ball catching. Can it be measured

Ball catching is a skill included in most tests for assessing the motor impairment of children with a mild motor deficit. To objectively measure ball catching short and long ball catching tests were developed to assess children between seven and nine years of age. The long test made use of a tennis ball machine to standardise the ball throwing procedure. The performance of the children was videotaped and scored at a later stage by means of a scoring system that allowed differentiation between several catching strategies. The short test made use of manually thrown balls and the number of successfully caught balls was used as the outcome measure. Reliability and validity of the tests was investigated in three studies with children from mainstream schools ( N =90, N =72, N =43). The Intra Class Correlation coefficients of test-retest and intertester reliability were good for both tests, ranging between 0.87 and 0.91. Between the short and long ball catching tests a correlation coefficient of 0.84 was found. Boys were better ball catchers than girls. Although further investigations are necessary, the results of these studies indicate that the rigorous standardised short ball catching test, consisting of 50 trials, is a reliable and valid instrument for measuring ball catching performance.

New reference values must be established for the Alberta Infant Motor Scales for accurate identification of infants at risk for motor developmental delay in Flanders

BACKGROUND The Alberta Infant Motor Scales (AIMS) is a reliable and valid assessment tool to evaluate the motor performance from birth to independent walking. This study aimed to determine whether the Canadian reference values on the AIMS from 1990-1992 are still useful tor Flemish infants, assessed in 2007-2010. Additionally, the association between motor performance and sleep and play positioning will be determined. METHODS A total of 270 Flemish infants between 0 and 18 months, recruited by formal day care services, were assessed with the AIMS by four trained physiotherapists. Information about sleep and play positioning was collected by mean of a questionnaire. RESULTS Flemish infants perform significantly lower on the AIMS compared with the reference values (P < 0.001). Especially, infants from the age groups of 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 and of 15 months showed significantly lower scores. From the information collected by parental questionnaires, the lower motor scores seem to be related to the sleep position, the amount of play time in prone, in supine and in a sitting device. Infants who are exposed often to frequently to prone while awake showed a significant higher motor performance than infants who are exposed less to prone (<6 m: P = 0.002; >6 m: P = 0.013). Infants who are placed often to frequently in a sitting device in the first 6 months of life (P = 0.010) and in supine after 6 months (P = 0.001) performed significantly lower than those who are placed less in it. CONCLUSION Flemish infants recruited by formal day care services, show significantly lower motor scores than the Canadian norm population. New reference values should be established for the AIMS for accurate identification of infants at risk. Prevention of sudden infant death syndrome by promoting supine sleep position should go together with promotion of tummy time when awake and avoiding to spent too much time in sitting devices when awake.

Psychometric properties of a motor skill checklist for 3- to 5-year-old children

BACKGROUND   Early identification of children with developmental co-ordination disorder is important. Teachers may be very useful in this identification process. The objective of this study was to develop a motor skill checklist (MSC) for 3- to 5-year-old children to be completed by teachers, and to establish the psychometric properties of this new instrument. METHODS An MSC of 28 functional items was constructed in close consideration with clinical experts and teachers. In regular schools, 366 pre-school children were rated with the MSC by their teachers (n= 111). To determine test-retest reliability, each teacher completed 4 weeks later the MSC again for one randomly selected child. In 22 classes with two teachers sharing the job, both teachers were asked to fill in the questionnaire. A subgroup of children was also tested with the Movement Assessment Battery for Children (M-ABC; n= 122). All teachers were invited to complete a questionnaire to evaluate the MSC. RESULTS The internal consistency of the MSC was high. The test-retest reliability was good. Inter-rater reliability was adequate except in the 5-year-old children. There was a strong correlation between the checklist and the M-ABC, establishing concurrent validity. Most teachers judged the MSC as easy or rather easy to complete. CONCLUSIONS The MSC is a reliable, valid and useful instrument to identify and assess young children with motor difficulties.

Evenwicht, een belangrijk knelpunt in de motorische ontwikkeling van kinderen met een gehoorstoornis

Volgens ‘Kind en Gezin’ worden in Vlaanderen jaarlijks 2,5 tot 3 per duizend kinderen geboren met een gehoorstoornis. Van hen heeft 1 tot 1,4 een ernstige bilaterale gehoorstoornis (Kind & Gezin, 2005). Naargelang de aard kan gehoorverlies onderverdeeld worden in conductieve doofheid of slechthorendheid, neurosensoriele doofheid of slechthorendheid, gemengde predominant conductieve of predominant neurosensoriele doofheid of slechthorendheid en centraal auditieve doofheid (Northern en Downs, 2002). De oorzaak van de gehoorstoornis kan genetisch zijn, pre-, peri- of postnataal verworven zijn of onbekend (Mansbach, 2006; De Nobrega et al., 2005).