The human sternum is located in the midline of the anterior chest, and the sternal stalk is the uppermost part of the sternum, located below the sternoclavicular joint on both sides, in the middle of the first sternal rib joint on both sides, and above the middle of the second sternal rib joint on both sides. Once the protrusion of the sternal stalk occurs, one should consider whether the stalk joint above the sternum has an abnormal angle. Most of them are caused by developmental abnormalities, such as the presence of a small amount of vitamin D or calcium deficiency during development, which can trigger a slight abnormality and slight protrusion of the sternal stalk and sternal angle. Due to prolonged external stimulation, strength training or excessive strain on the upper limbs, the first thoracic rib joint may become deformed, thus causing the protrusion of the sternal stalk, which is usually seen in special occupations or fitness trainers, professional athletes, etc. If it is accompanied by other physical symptoms, such as pain or deformities in other parts of the body, you should seek medical attention promptly.