Under normal circumstances the sternum is too soft there may be the possibility of two diseases: first, in the process of the child’s growth and development of the lack of, leading to the child’s acquired calcium deficiency, calcium and phosphorus metabolism abnormalities, and the emergence of the sternal cartilage. Secondly, it is related to genetic factors, inborn human family metabolism leads to abnormal calcium and phosphorus metabolism, and the emergence of familial chondromalacia, it is related to inborn factors. Under normal circumstances are related to the acquired factors, the acquired lack of calcium and phosphorus metabolism caused by abnormalities, resulting in the emergence of the softening of the sternum, in order to prevent the appropriate sun supplement vitamin D, you can also be appropriate to supplement the calcium supplements, in addition to the necessary exercise for the deposition of bones is of some help.