婴幼儿躯干短,而裤子多较长,因此裤腰总是系在平乳头的胸部,不象成人的裤子系在平脐部。构成婴幼儿胸廓的肋骨和胸骨还没有骨化,也就是说还不够硬,尤其是胸廓前半部带有弹性的肋软骨,甚为娇弱,不能承受急绷绷的宽紧带的压力,久而久之,相应部位的胸廓会凹陷变形。如果这个婴幼儿本来就缺乏维生素D和 Trousers for infants and young children are short, while the pants are longer, so the waistband is always tied to the flat nipple’s chest, unlike the adult’s trousers tied to the flat navel. Chest ribs constitute the infants and young children have not ossification of the sternum, that is not enough hard, especially in the first half of the thoracic elastic rib cartilage, very fragile, can not afford the pressure of the emergency taut wide band, as time passes , The corresponding part of the thoracic cavity will be deformed. If this baby is already deficient in vitamin D and