In clinical work, we often encounter patients with knee injuries who are well exercised in knee flexion function but cannot fully straighten the knee joint. Patients with incomplete knee often complain of walking with a limp, not being able to run fast, and not being able to fire their feet properly. Therefore, it is important to pay attention to knee extension exercises. Exercise methods are as follows: 1. Lie on your back in bed, or in a sitting position, with a small pillow below the ankle of the lower limb, about 10-375px high, completely relaxing the muscles and relying on the weight of the leg to naturally sag to achieve full extension. You can also press a weight on the distal thigh, neither directly above the patella nor the proximal calf, directly on the knee, which will increase the pressure between the patella and the femur, and the prolonged compression will cause new injuries. Weights such as sandbags or salt bags, the weight of the weights to 20 minutes of pain can tolerate as appropriate, the entire 20 minutes requires the full relaxation of the muscles of the posterior thigh group, once 20 minutes, generally 2 times a day. 2, prone position, lying on the side of the bed, with soft pillows to knee pad up or empty outside the bed, the knee to far hanging, rely on the weight of the leg natural sag to reach completely straight. You can also hang weights at the ankles, or tie heavy objects, such as sandbags or salt bags, the weight of the weights to the pain can tolerate. This method especially requires the muscles of the lower limbs to be relaxed and not “hard”. It is also 20 minutes at a time, generally 1-2 times a day. Note: 1, straightening exercises should be separated from the flexion exercises for a longer period of time, such as a morning practice, the other on the afternoon practice. This is to avoid mutual influence, offsetting the effect of the exercise, while increasing the inflammation and swelling of the joint because of excessive stimulation. The knee joint swelling and pain after the exercise can be iced. 2, in the process of knee straightening exercises, if the muscles on the back of the thigh or the joint capsule on the back side of the knee feel a pulling sensation, or a slight pain from the pulling, is normal and we want to happen. Do not contract your muscles to fight this feeling, but try to relax them completely to adapt to the sensation. Otherwise, the muscles that need to be stretched are contracted against, making the straightening exercise ineffective. 3, the entire process of knee straightening exercises, do not have pain in the middle of a break, if the pain is serious because it can not hold for 20 minutes, you should reduce the weight. If the pain interrupts the exercise, the contracted tissues will just be stretched and then relaxed, and will quickly shrink back to short, so the exercise will have little effect. So if you can’t hold on for 20 minutes, it means that the weight is too heavy, then don’t grit your teeth and hold on, but should adjust the weight and practice again.