The applied ability in infant crawling and the importance of prone motor experience for subsequent development

Abstract Background: In the process of motor learning in human, many movement patterns, that is, many variations, are tried first, and more efficient movements come to be selected based on experience of trial and error. Although this process for selection (i.e., variability) is particularly active in infancy neurodevelopment and motor development, few studies have explored the variation / variability of infant crawling.Aims: The first is to investigate the difference in the variability of hands-knees crawling between typically developing infants with and without belly crawling experience. The second is to examine the relationship between development after 2 years of age and crawling variability.Study design: This study was longitudinal. Crawling variability was evaluated by encoding crawling variation in infants not pointed out neurological or orthopedic problems. We investigated the differences in the quantity and content of hands-knees crawling variation between infants with and without belly crawling experience. Further, we retrospectively explored the difference in the whole quantity of crawling variation during both belly and hands-knees crawling stages between two groups, suspicious and normal in DENVER Ⅱ conducted after 2 years of age.Results: The quantity of hands-knees crawling variation was significantly smaller in the group with belly crawling experience than the group without the experience. On the other hand, the content of hands-knees crawling variation was almost the same between these two groups. In addition, there was a significant difference in the whole quantity of crawling variation between the suspicious and the normal group.Conclusions: The current study shows that infants improve the learning efficiency and variability of hands-knees crawling movements by applying skills acquired through belly crawling experience, which provides one interpretation of the importance of sensorimotor experience in the prone position in infancy. Furthermore, this study suggests a link between crawling variability and subsequent development.