In Japan previous data did not consider distinguishing between infants' creeping, hands and knees crawling and hands and feet crawling. Therefore the process of these motor skills has not been clearly understood in the national literature and it is incomparable with well-defined international data. In 2015 a detailed questionnaire survey of 307 infants in three prefectures (Hyogo, Okayama and Tottori) revealed that the majority of infants (76.1%) did both creeping and hands and knees crawling. The length of crawling was most frequent between 3 and 4 months, which is a similar figure compared to international research findings. The results further included the measure of shuffling, which is an irregular way of crawling on the back. Substantially 14.7% infants did not process with hands and knees crawling. 11.1% of the group skipped the complete acquisition process and progressed to walking without doing either creeping or any types of crawling.
