Bumps on both sides of the shoulder are commonly caused by acromioclavicular arthritis, so the only way to get rid of the bumps is to treat acromioclavicular arthritis. Shoulder lock arthritis is caused by repeated overactivity of the shoulder, which leads to wear and tear of the shoulder lock joint cartilage, resulting in aseptic inflammation and increased inflammatory exudation in the joint, causing local swelling and a bump in the appearance. After the inflammation subsides, the swelling and bulge will be eliminated. If conservative treatment does not work, MRI can be performed to clarify the extent of the lesion, and if necessary, surgery can be performed.