DEVELOPMENTAL-CHANGES IN INTERLIMB COORDINATION - TRANSITION TO HANDS-AND-KNEES CRAWLING

A short-term longitudinal study was conducted to assess changes in the patterning of the limbs during infants' transition to hands-and-knees crawling. Six infants were studied wing observational and kinematic a ssessment techniques. The results revealed that all 6 infants converge d on the same diagonal interlimb pattern for locomoting shortly after developing sufficient muscle strength to support their abdomens above the support surface. This Finding is significant because forward prone progression could be accomplished using any number of interlimb patte rns (e.g., moving one limb at a time), yet a diagonal pattern is the m ast flexible and dynamically efficient. The process by which this beha vioral pattern emerges appears consistent, with recent developmental t heories suggesting that new responses are selected to optimize perform ance following periods of increased variability induced by changing or ganismic or environmental conditions.