Locomotor strategies preceding independent walking: prospective study of neurological and language development in 424 cases.

Locomotor strategies used before the acquisition of independent walking were studied in 424 infants. 270 were survivors of neonatal intensive care (the index group); the other 154 (controls) had had no perintal complications. Five forms of locomotion were distinguished: crawling on hands and knees, creeping on the stomach, bottom-shuffling, other, and none before independent walking. Crawling was the most common form of locomotion in both groups. A higher percentage in the index group were late crawlers (greater than 10 months), but similar proportions in both groups were bottom-shufflers or simply stood up and walked. One of the most important factors influencing locomotor strategies was asymmetry. Analysis of the influence of locomotor strategies on psychomotor and linguistic outcome up to five years showed no significant relationships within the index group. However, within the control group, infants who crawled had a statistically greater incidence of later motor delay, which is in contrast to the findings of other studies.