The inability to lift the arm with pain may have the following two causes: 1. Frozen shoulder: Frozen shoulder can lead to impaired movement of the shoulder joint in all directions, especially when the arm lift is restricted very significantly, and the symptoms of inability to lift the arm can occur, which should be treated early to prevent the shoulder joint from stiffening and leading to permanent joint movement restriction. 2. Impingement syndrome: Impingement syndrome of the acromion causes Rotator cuff tears, with age or due to congenital abnormal development of the shoulder joint’s acromion, lead to acromion impingement. This results in a rotator cuff tear, which causes pain in the shoulder joint and the inability to lift the arm. This is because there are tears in the muscles and tendons that affect the lifting of the shoulder joint. Early diagnosis and, if necessary, arthroscopic surgery to remove the rotator cuff and suture the rotator cuff can restore the integrity of the rotator cuff, allowing the arm to be lifted and the pain to be relieved.