Wrench Wrist is a popular wrestling game among young people, and even professional event organizers around the world regularly hold competitive wrist wrenching competitions. However, don't underestimate the strength of the wrench, losing the wrench is not just a loss of face. With a crisp click and a severe pain, the loser's arm may be pulled at a strange angle, which is a common complication in wrist wrenching - humeral shaft fracture. Today, the doctor will share with you the precautions for wrist wrenching. How can a wrist fracture occur? Wrench wrist can cause various bone and joint injuries, including humeral shaft fractures, humeral epicondylar avulsion fractures, etc., but the most common one is still humeral shaft fractures. The Department of Trauma and Orthopedics at Beijing Jishuitan Hospital can treat approximately 15 cases of humeral shaft fractures caused by wrist wrenching per month. Most of them are young men who were accidentally injured in entertainment competitions with friends. The mechanism of humeral shaft fracture caused by a wrench wrist is related to the anatomical characteristics of the humerus itself and the imbalance of muscle group strength during competition. The middle section of the humerus is a cylinder, gradually extending into a flat triangle towards the distal end. The humerus is relatively weak at the transition from a cylinder to a triangle, and the maximum stress load when applying torsional stress to the humerus is also concentrated here. During the wrist wrenching process, the opponent will apply an external rotational stress to the distal humerus through the competitor's forearm. During the confrontation, the contestant applies strong internal rotation stress to the proximal humerus through their internal rotation muscle group, and the huge torsional stress is released at the weakest point of the humerus, resulting in humeral shaft fracture. Whether the wrist will break or not is not related to the strength of the opponent. Due to the common injury mechanism, the appearance of humeral shaft fractures caused by a wrench wrist is very similar. This type of fracture is almost always a one-third spiral fracture of the distal humerus, with half accompanied by butterfly shaped fracture fragments and may be accompanied by radial nerve injury. The risk factors for humeral shaft fractures caused by wrist wrenches include a history of repeated wrist wrenching exercises (greater than 2 years), alcohol consumption, and lack of warm-up before competitions. Contrary to our understanding, people who engage in long-term wrist wrenching may be more prone to developing humeral shaft fractures. This may be related to their excessive and uneven development of upper limb muscles during long-term competition and training. In addition, whether wrist wrenching is prone to humeral shaft fractures is not related to the strength of the opponent, but the risk of wrist wrenching fractures is similar to that of people who are stronger, weaker, or at a similar level. There are various treatment options for humeral shaft fractures, including non-surgical treatment, closed reduction intramedullary nail fixation, and open reduction plate screw fixation. When using non-surgical treatment, the affected limb can be fixed with hanging plaster or closed reduction followed by upper arm U-shaped plaster fixation. After 2 to 3 weeks, the elbow joint can be liberated and fixed with functional braces for 10 to 12 weeks. Due to wrist wrenching, almost all humeral shaft fractures are spiral fractures of the distal third of the humerus. Closed reduction and intramedullary nail fixation are not suitable for this type of fracture. Open reduction and plate screw fixation are the best surgical treatment for this type of fracture. The treatment of humeral shaft fractures requires consideration of various factors such as the type of fracture, degree of injury, and functional needs of the patient. Therefore, patients should consult a professional orthopedic doctor before making a decision