There are two possible causes for shoulder problems: 1. Frozen shoulder. Frozen shoulder is a degeneration in the elderly or due to long-term shoulder inactivity, such as shoulder joint trauma or upper limb trauma, long-term braking leads to reduced shoulder joint activity, resulting in stiffness, which can lead to frozen shoulder. In most cases, this can be relieved after one year. 2. Rotator cuff injury, with degeneration and chronic damage to the rotator cuff in the elderly, rotator cuff tears can occur, resulting in the inability to lift the shoulder. In severe cases, arthroscopic surgery is required.