Although a knee fall is only a process of injury, there is no way to clarify the exact severity of the entire injury, but in terms of general treatment principles, after a fall with significant pain, you should not bend or straighten the knee, and should rest in bed as much as possible, and do not walk on the ground. If the pain gradually decreases or even disappears during the whole process, it means that the whole process of the fall is not particularly serious. If there is no significant improvement within a week or so, and the swelling and pain are still evident, you need to go to the hospital to complete a radiograph or MRI to rule out any fracture or ligament damage to the knee joint during the fall. In severe cases, surgery may be required to resolve the problem, not to mention early knee extension and bending activities. You must wait until you have recovered from surgery before you can perform functional rehabilitation exercises for straightening and bending.