Psychometric properties of the qualitative assessment of manual dexterity in the MABC-2 test

Background: The Movement Assessment Battery for Children Test, 2nd edition (MABC-2 test) is a widely accepted standardized method for the assessment of motor competency and identification of developmental coordination disorder in children. However, there are no information on psychometric qualities of the qualitative part of the test.Objective: To reveal possible limitations of the qualitative assessment of the MABC-2 test tasks of the age band 2 (7-10 years), we examined the inter- and intra-rater reliability and construct (known-groups) validity, specifically for observation of the manual dexterity (MD) tasks. Methods: The MD tasks of the MABC-2 executed by children with and without motor difficulties in manual dexterity (MD- and MD+; N = 6) were recorded by a video camera. A group of investigators (N = 9) performed qualitative observational assessment of children's movements from video recordings, in two observation sessions apart by four weeks (time 1, time 2). Results: The statistical tests rejected the hypothesis on significant inter-rater reliability in the number of marked signs in the MD tasks. Regarding the intra-rater reliability, the number of marked signs in the MD tasks was not significantly different between observation in time 1 and time 2 in all investigators. 95% agreement limits for the number of marked movement signs in the two repeated observations ranged from Mdiff ± 0.73 up to Mdiff ± 2.63 signs. A good construct validity of the qualitative assessment of movements in the MD tasks was indicated by significantly higher number of movement signs marked in the MD- children as compared to the MD+ children, with exception of the graphomotor task. Conclusions: The qualitative assessment within the MABC-2 test is a useful tool for the identification of manual dexterity impairment and weaker aspects of hand-eye coordination. However, the qualitative observational assessment of the MABC-2 tasks demands specific training of users.