After knee surgery, most patients will have limited mobility of the joint. This is why it is important to practice the “leg break” after knee surgery. Here are some simple ways to do this. First of all, knee extension is more important than knee flexion in terms of knee function, because if a person has normal knee extension and only 90 degrees or so of knee flexion, he or she can walk without problems. But even if the knee can be flexed to the full angle, but the knee extension is 10 degrees worse, then the person must be walking with a limp. So the focus of our post-operative exercises should be: knee extension! For patients with ACL reconstruction, knee extension exercises are even more important, because first of all, many of us take the tendon of the N cord muscle, which is an injury in itself, so after this injury, we must strengthen the knee extension. Many people will complain of soreness and pulling pain on the back side of the knee, which is normal for tendon removal. Other patients are unable to straighten their knee before surgery because of meniscal cards or strands, or swelling, so it is even more important to strike while the iron is hot early in the post-operative period! The most common method of knee extension is the “tiger stool” method: the heel is pushed up and the knee joint is left empty, if this straightens the knee and there is a pulling sensation on the back side of the joint, then OK, keep it like this for a long time. If the above method still can not straighten, then you should add appropriate pressure sandbags to consolidate the effect. Sandbags are usually 5-10 pounds each, and can be replaced with other materials such as rice bags. The area to be pressed should avoid the position of the patella. Each time at least 30 minutes. For a few patients with severe limitation of knee extension, sometimes a straight splint is needed after the “tiger bench”. Of course, another method is to lie on the bed with the leg outstretched and then apply pressure to the ankle with a sandbag. These two methods can be crossed with each other. Bend the knee method: Bend the knee in a variety of ways, in order to practice in the order of the size of the angle. At the very beginning, you can sit and hang your leg like this. When the angle is larger, you can use a good foot to help press. Sitting leg drops can usually be practiced to about 90 degrees. After that, you can use supine leg drop, through the effect of gravity to let the lower leg naturally drops, so that usually can reach about 100 degrees. Patients who have difficulty flexing their knees can also practice in a seated position against the wall. When the angle is greater, a seated leg hold can be used to reach an angle close to 120 degrees. The last few tens of degrees can be achieved by kneeling and using one’s own weight to press down. (Note that this method is prohibited for post-operative posterior cruciate ligament patients.) Some patients may feel pain on the posterior side of the joint when kneeling, so this can be changed to a squat. Usually one knee flexion exercise per day in the early post-operative period is enough, and each time we try to solve the battle within 20 minutes, otherwise repeatedly tossing the joint also tends to cause swelling and pain. Of course the exercises should also be combined with ice immediately afterwards. Most patients are able to recover normal joint mobility in about 2-3 months, but if there is no progress for a long time, you should also seek medical attention to prevent joint adhesions from occurring. The process of “leg breaking” is painful and some patients give up training because of the fear of pain, which eventually leads to joint adhesions. We have to face the pain, face the pain, and overcome the pain so that we can recover our health as soon as possible!