Alberta Infant Motor Scale

Background: The Alberta Infant Motor Scale (AIMS) has been developed in Canada in the 90ies. The AIMS and its Canadian norms are frequently used across the world to monitor infants' gross motor development. Currently, it is disputed whether the Canadian norms are valid for non-Canadian infants. Aims: To compare scores on the AIMS of Dutch infants with that of the Canadian norms, to compare the sequence of motor milestones in Dutch and Canadian infants, and to establish Dutch AIMS norms. Study design: Cross-sectional study. Subjects: 1697 infants, aged 2–18 months, representative of the Dutch population (gestational age 39.7 weeks (27–42)). Outcome measure. AIMS assessments, based on standardized video. Perinatal and social information was obtained by questionnaire and medical records. To create Dutch reference values quantile regression with polynomial splines was used. Results: 1236 Dutch infants (73%) scored below the 50th (P50) percentile of the Canadian norms, 653 (38%) below the P10 and 469 (28%) below the P5. In infants aged 6 to 12 months these values were: 567 infants (81%) < P50, 288 infants (41%) < P10, 201 infants (29%) < P5. The sequence of achievement of motor milestones of Dutch and Canadian infants was similar. Dutch norm-reference values of the AIMS were calculated. Conclusions and implications: Gross motor development of Dutch infants is considerably slower than that of the Canadian AIMS norms sample. To prevent overdiagnosis of developmental delay and overreferral to paediatric physiotherapy Dutch AIMS norms are required. The paper introduces these norms, including percentile ranks.