Knee hyperextension is also known as knee hyperextension or anticuspension. Knee hyperextension can be judged by the presence or absence of pain in the knee joint, the presence or absence of functional flat feet, the presence or absence of lumbar pain, and the presence or absence of deformation of the bones of the lower limbs. 1. Whether there is pain in the knee joint: the knee joint of patients with knee hyperextension will bear a greater burden than others when they stand up and stomp on the ground, which will easily lead to damage to the knee joint and spasm of the surrounding soft tissues, and there will be pain in the knee joint. 2. Whether there is functional flat foot: knee hyperextension will lead to excessive tension of the plantar or posterior calf fascia, and insufficient heel support, resulting in fallen arches, which will easily lead to functional flat foot. 3. Whether there is lumbar pain: compared with normal people, patients with knee hyperextension will shift the center of gravity forward to maintain body balance, and the center of gravity will trigger anterior pelvic tilt, which can lead to lumbar pain. 4. Whether the bones of the lower limbs are deformed: patients with mild hyperextension of the knee are prone to calf pain, forming muscle legs, while patients with severe hyperextension of the knee will have deformation of the bones of the lower limbs, resulting in X-shaped legs or O-shaped legs. When the patient suspects the occurrence of knee hyperextension, he should consult the hospital in time, make a clear diagnosis through physical examination and auxiliary examination, and correct it through active training in his life, and if necessary, he should be treated and corrected under the guidance of the doctor.