The size of the clavicle is generally genetically determined, if the left and right sides of the clavicle shape is proportional, there is no obvious deformity, both sides of the angle of the clavicle also belong to the normal state, this situation is a normal phenomenon. People with thick bones prove that they have a better physique. If the clavicle is thick, it may be caused by acquired habits. The length of a normal adult’s clavicle is already fixed, and the clavicle will stop developing longitudinally around the age of 25. Before the age of 25, the clavicle can become longer, but after the age of 25 the clavicle can’t become longer; after the age of 25, the clavicle will gradually thicken with age and limb movement. If large bones are accompanied by other symptoms, such as obvious bone deformities or pain, local radiographs should be examined promptly to prevent tumors or other lesions of the bones.