Since 1992, parents have been urged to place their infants on their back when asleep. The resulting lack of experience in a prone position appears to cause developmental delay in infants. Use of various infant equipment, except baby walkers, has not been examined thoroughly to establish their influence on the motor development of infants. The aim of this systematic review was to evaluate the effects of sleep and play positions, and use of infant equipment, on motor development. Nineteen studies with evidence at level II were selected against the selection criteria and scored against the Physiotherapy Evidence Database scale. Despite the generally poor methodological quality, the studies have consistently shown that there was transient delay in motor development for healthy term and low-risk preterm infants who were not exposed to the prone position or who did not use infant equipment. However, most of these infants walked unaided within a normal time frame. Limited evidence was found for the effect on more vulnerable infants. More rigorous longitudinal studies using outcome measures focusing on movement quality are recommended to understand any long-lasting influence on the motor skills in these infants.