The positions you place your baby in can have an effect on posture and development. When your baby is on his or her back in a car seat, on the floor, or supine sleeping, it can cause flattening of portions of the skull. Babies are also prone to plagiocephaly, or misshapen skull if they have conditions like congenital torticollis where there is spasm of the sternocleidomastoid muscle in the neck. Having baby nurse only on one side or bottle feeding baby on the same side can ma