Hyperextension of knee flexion is also called hyperextension of knee joint, usually caused by over exertion or trauma, degenerative bone disease and knee injury, etc. Different causes, different treatments, commonly used treatments include general treatment, medication, surgery and so on. 1. Overexertion or trauma: the tendons and ligaments around the knee joint deteriorate, and the lack of protection and support leads to hyper-extension of the knee flexion, it is recommended to consult a doctor in time, and restorative exercise can be enough for mild symptoms, while orthopedic appliances are needed for serious symptoms. 2. Degenerative bone diseases: due to severe osteoporosis caused by joint degeneration leading to hyper-extension of knee flexion, need to be given calcium supplements and vitamin D supplements and other timely treatment, while strengthening muscle exercise. 3. Cruciate ligament injury or joint capsule injury: if the knee flexion hyper-extension is caused by the damage of the internal structure of the knee joint, it is necessary to do knee joint MRI to observe whether there is any structural damage, and if it is found that the above mentioned damage is found, it is necessary to carry out the surgical treatment such as knee arthroscopy in a timely manner, so as to repair the damaged part. Congenital rickets and chondromalacia may also lead to hyperflexion of the knee, and it is recommended to consult a doctor in time and follow the doctor’s instructions to standardize the treatment when symptoms are detected. The use of medication should be in accordance with medical advice.