Five months after a comminuted fracture of the humerus, the inability to rotate is due to the lack of early functional exercise post-fracture, leading to severe adhesions in the joint and upper arm muscles, which significantly restrict rotation. This condition can be gradually recovered through later functional exercises, slowly tearing apart the adhered muscles, and increasing the range of motion of the humerus. It is recommended that patients seek rehabilitation treatment in the physical therapy department of a hospital. Additionally, various physiotherapy methods can be used to improve local blood circulation, promote muscle healing, relieve joint and muscle stiffness, and methods such as electrotherapy and magnetotherapy can also be applied to assist in improving the rotational capacity.