soothing effect on babies. After 6 months of age or more, infants begin to resist being placed in cradleboards more vigorously as they become more mobile, and they are often placed in the cradleboard with their arms and hands free, so that they can play with objects hung from the cradleboard for their amusement. Developmental dysplasia of the hips Cradleboard use has been associated with increased incidence of developmental dysplasia of the hip. The technique requires straightening the legs, which encourages dislocation of the femur and malformation of the acetabulum. This can be avoided by placing padding between the baby's legs to keep the knees slightly bent with the hips angled outwards. Some modern cradleboard users contend that the small 1968 study of Navajo babies was intentionally designed to denigrate a traditional cultural practice, although a 2012 study produced hip dysplasia in laboratory rats by subjecting them to similar conditions. See also Baby jumper Baby sling Baby transport Papoose Swaddling External links Victor F. Lotrich, "Indian terms for the Cradle and the Cradleboard", The Colorado Magazine, May 1941 References Babycare Human-powered vehicles Infancy Child safety Carriages Baby products Bags Sámi culture