The pain may be caused by the following reasons: First, there may be bone and joint-related injuries in the upper limb, such as radial subluxation or elbow dislocation in the upper limb, which may cause severe pain when the patient tries to straighten the upper limb. Second, it may be caused by excessive fatigue, such as excessive exercise of the upper extremity, such as excessive flexion and extension of the elbow joint, which may cause excessive fatigue of the relevant muscles and induce significant pain in the process of straightening the upper extremity; third, it may be caused by Such diseases are often caused by the passive overstretching of the upper limb, which leads to the above-mentioned injuries and pain; fourth, they may also be caused by joint adhesions of the upper limb, which are often seen in patients with serious injuries to the upper limb, without sufficient functional exercise during the recovery process, which leads to joint adhesions of the upper limb, especially the elbow joint. The above symptoms may occur when the joints of the upper limbs, especially the elbow joint, become adherent.