First of all, it should be noted that all the exercise methods described below must be started under the guidance of professional doctors and therapists. Meanwhile, due to the different surgical methods and clinical treatments in different hospitals, the exercise methods and timing may vary accordingly, so they can be used as a reference for post-operative rehabilitation. I. Inflammatory reaction period: (0-1 week after surgery) Problems to pay attention to: One of the important problems in this period is how to position your leg after surgery. The correct way to do this is to place the operated leg on a pillow to elevate it, so that it can be positioned higher than the heart to promote circulation when you are lying in bed. The toes should be pointed straight up, not crooked to one side. Most importantly the knee should be empty underneath, never with a pillow underneath the knee and never with the leg becoming slightly bent! This position keeps the knee in a slightly flexed position of 10-30°, the joint space of the knee will be larger, the joint is most relaxed, so the pain is mild and the patient himself will find this the most comfortable position. However, this causes the capsule on the posterior side of the knee to always be in a relaxed state, and at the same time, the infrapatellar fat pad, which has been stimulated by the surgery, will proliferate and may grow into the enlarged anterior side of the joint space. With the tissue contracture at the back of the joint being stretched tight, and something occupying and jamming the front, the knee’s angle of extension is limited! (The serious consequences of this are written in “Why Joints Adhere”.) So as long as the pain is not intolerable, it is better to keep the leg in as straight a position as possible in order to facilitate the recovery of function. Another thing to keep in mind is that you should not walk too much even if the pain is mild and you are in good shape after the surgery! Don’t think that it is the leg that is the problem and use walking as an exercise! It is very wrong to think that you should practice walking because you can’t walk! Walking is a very complex function of the lower limb, there must be enough muscle strength, mobility, proprioception must be fine, joints must be stable enough, pain and swelling must be within a certain limit, etc., etc., etc., and can never be practiced by trying to walk. At the same time too much walking in the early stages and early days after surgery will inevitably cause swelling and fluid buildup in the knee joint, which not only affects the recovery of function, but persistent swelling and inflammation can also jeopardize the healing of the tissues! Moreover, at this stage, due to pain and weakness, as well as fear and self-protection, the walking posture is not correct, and all walk with a “limp”. The more this posture is practiced, the more the “power stereotype” of the wrong movement is consolidated, and the more firmly remembered, many patients walk with a “limp” even after the knee function has been restored to a certain level, partly because of this. Therefore, in the early stage, except for the necessary activities of daily life (going to the toilet, washing face, brushing teeth and so on), do not go down to the ground to practice walking. Of course, these words do not mean to say that walking will cause a lot of negative consequences, so do not walk if you can, do not go down to the ground if you can, and try to minimize the activities is right. If the tissue condition does not allow it, or some treatment in the surgery does not allow it (such as the meniscus suture, cartilage certain treatment), when it is time to get down to the ground to bear weight and walk, it is necessary to walk, but just need to control the time to get down to the ground and the amount of walking. Failure to get down to bear weight will result in degeneration of the cartilage, loss of joint control and proprioception, and decalcification of the bone, again affecting recovery of function and healing of the tissues! I remember a few years ago there was a TV show theme song that was widely sung, called “When it’s time to hit the ground running, hit the ground running”. We can apply the same phrase here, “When it’s time to load up, load up, when it’s time to walk, walk” ! Too much or too little walking can be a problem, as mentioned earlier, just do the walking necessary for daily living and don’t practice with walking! Functional rehabilitation exercises to be done: On the day of surgery: after the anesthesia has worn off, you can start to move your toes and ankle joints to promote circulation and sensory recovery. If the pain is not unbearable, you can start doing the ankle pump exercises detailed earlier in Ankle Pump – Simple but Important Lower Limb Functional Exercises. 1 day after surgery: 24 hours after surgery, if the vital signs are stable and the pain is not unbearable, you can walk on the operated leg without touching the ground with the help of crutches under protection. However, as mentioned earlier, only necessary daily life activities such as going to the toilet are encouraged, and absolutely no walking can be practiced exclusively! (1) “Ankle pump” exercise: It is the active flexion and extension of the ankle joint, requiring slow, forceful, maximum activity within the scope of not causing significant pain, repeated and consecutive exercises. It is best to do as much as possible when you are not sleeping, and at least 5 minutes/hour is needed. It is only then that the importance of promoting circulation, reducing swelling, and preventing deep vein thrombosis can be achieved. The specific mechanism and content is written in detail in “Ankle Pump – Simple but Important Lower Extremity Functional Exercises”. (2) Quadriceps isometric contraction exercises: that is, the muscles in front of the thigh (should be counted as muscle groups), tensing and relaxing alternating activities. Requirements under the premise of not increasing pain as much as possible, to be greater than 500-1000 times a day to have an effect. This exercise will minimize muscle atrophy in the lower extremities and will also improve circulation in the lower extremities. 500-1000 reps may seem like a lot, but if you think about it, you’ll realize that it’s not nearly enough! The function of the lower limbs is to stand and walk, go up and down stairs and so on, that is to say, it is to overcome the body weight in the work, so gently tensing and relaxing the intensity of the exercise can be how much? I’m sure you already understand the meaning. Exercises play a minimal role, only to slow down atrophy, for the quadriceps such a large muscle, far from enough to maintain and improve muscle strength! The specific mechanisms and exercises are written in detail in the Quadriceps Isometric Contraction – Lower Extremity Classic Muscle Strength Exercises. (3) N cord muscle isometric exercises: N cord muscle is the muscle group on the back of the thigh, the location and role of this muscle group has been mentioned in the previous article “rehabilitation of anterior cruciate ligament rupture of the knee (2) – arthroscopic anterior cruciate ligament reconstruction of the knee a brief introduction to the surgery”. The exercise is to press down hard on the surface of the bed with the heel and calf at the same time, or a pillow under the leg. At this point, if you feel the back of your thigh with your hand, you can feel the contraction of the N cord muscle harden. The main point is to keep the leg straight as you press down, otherwise bending the knee may cause pain or result in injury. Again the requirement is to do as many as possible without increasing pain, also greater than 500-1000 reps per day. The reasons and mechanisms were stated earlier and will not be repeated. (4) Straight leg raising exercises: Here, it is important to practice in different situations, that is, depending on the type of surgery, the timing and amount of exercises will be different. If the ACL is reconstructed with the tendon of the N cord muscle (specifically, the tendon of the thin femoral muscle and semitendinosus muscle), or if an allograft tendon is used, or if an artificial ligament is used, you can start to try to do the straight leg raising exercises because the damage to the anterior side of the knee is less and the pain is also less. However, time and frequency are not required during this period; the main thing is to maintain neuromuscular control and prevent disuse. So as long as you can lift every hour or two, too many exercises will increase the pain! The specific exercises are written in detail inside “Straight Leg Raises – Classic Lower Extremity Muscle Exercises”, so I won’t repeat them here. (5) If the patellar tendon (bone-tendon-bone) is used to reconstruct the anterior cruciate ligament, the patellar tendon incision will be very painful, you can delay until 2-3 days after surgery to try the “straight leg lift” exercise, do not have to force the exercise to increase pain and inflammation. 2 days after surgery: (1) Continue to strengthen the above exercises. (2) After walking on the ground, the affected leg may feel congested and swollen, so you need to strengthen the “ankle pump exercise” to promote blood return to the distal limb. It should be reminded not to stay off the ground for a few days for fear of congestion. The longer you stay in bed, the more pronounced the congestion and swelling will be when you get off the ground again. There is also the possibility of postural hypotension occurring, which can be even more problematic. So if your doctor thinks the tissues allow it, try to get off the floor and bear weight appropriately; delays will only increase complications and do no good. (3) Strengthening straight leg raising exercises: The purpose is to strengthen the quadriceps muscle strength, laying the foundation for knee stabilization and weight bearing on the ground. The amount of general practice is: 30 times / group, 30 seconds rest between groups, 2-4 groups of continuous practice, 1-2 exercises / day. Specific exercises written in detail in the “straight leg lift – lower limb classic muscle strength exercises” inside, will not be repeated here. (4) Lateral leg lifting exercises (including medial and lateral straight leg lifting): the purpose is to strengthen the muscles of the inner and outer thighs, the use of the N cord muscle tendon (specifically the thin femoral muscle, semitendinosus tendon) reconstruction of the anterior cruciate ligament of the patient, due to the tendon of the incision on the medial side, the pain in the practice of the medial straight leg lifting will be obvious, you can temporarily delay the practice for 1-2 days before you start. Specific exercises are written in detail in “Straight Leg Raise – Lower Extremity Classical Muscle Strength Exercises”, so I won’t repeat them here. The amount of general exercises is: 30 times / group, 30 seconds rest between groups, 2-4 sets of continuous exercises, 1-2 exercises / day. (4) Posterior leg raising exercises: For patients who use the N cord muscle tendon (specifically the tendon of the thin femoral muscle and semitendinosus) to reconstruct the anterior cruciate ligament, since the tendon of the N cord muscle of the posterior group of the thigh is taken, it may be obvious that the pain will be obvious when practicing the medial straight raising of the leg and the exercise can be temporarily postponed for 3-5 days before starting the exercise. Specific exercise methods are written in detail in the “straight leg raising – lower limb classic muscle strength exercises”, I will not repeat here. The general amount of exercises is: 30 times / set, 30 seconds rest between sets, 2-4 sets of continuous exercises, 1-2 exercises / day. All of the above straight leg raising exercises, after the strength is strengthened, you can tie a sandbag at the ankle joint as a load, to strengthen the exercises to better strengthen the muscle power. The amount of exercises is still 30 times / set, rest 30 seconds between sets, 2-4 sets of continuous exercises, 1-2 exercises / day. Note that it is the weight of the load that should be increased, not the number of repetitions or the time, see “Some principles of plyometric exercises” for more details. 3 days after surgery: Depending on the surgery and the condition of the tissues, the doctor will decide whether early passive joint mobility exercises can be started. (1) Again, continue to strengthen all of the above exercises. (2) Weight-bearing and balance exercises for the affected leg (pay attention to whether there are meniscus sutures and articular cartilage treatment): On the basis of being able to go down to the ground, the affected leg can be dipped into the ground and weight-bearing, and stand on the wall or a chair, etc., which can be stabilized and protected at any time. The muscles of both legs should be tensed to control the balance of the body, and then gradually move the center of gravity of the body to increase the degree of weight-bearing and exertion of the affected leg. In this way, in 1-2 weeks, gradually reach the affected side of the single leg can be fully weight-bearing standing level. The typical volume of exercises is 5 minutes/repetition, 2 repetitions/set, 2-3 sets/day. When you have practiced to the point where you can stand on the affected leg for 1 minute on one leg, you can walk without crutches. Of course it is still important to protect it carefully! (3) Depending on the situation, start passive knee flexion exercises: within the range of slight pain, the muscles are completely relaxed, using the “bedside leg drop” method. Remove the splint or brace during the exercise and be sure to put the splint back on afterward! The whole process is limited to about 10 minutes, do not repeat, 1 time / day practice, to avoid inflammation and pain increase. What’s more, avoid violent pushing and blindly pursuing angles to speed up the exercises! (4) After the above knee flexion exercise, immediately apply ice for about 20 minutes to avoid swelling and bleeding. If there is usually a noticeable warmth and swelling in the joint, ice again 2-3 times/day. Of course, there is also cotton leg compression bandage, there is no need to ice. (5) Knee extension exercises: patients who can not reach normal knee extension before surgery, must practice straightening, otherwise it will be difficult to solve the later extension limitations! If the angle is normal before surgery, just pay attention to the correct position at the beginning of the article, and wait until the flexion angle is increased before starting extension exercises. Again, remove the splint or brace while practicing and put the splint back on after practicing! It is important to note that there should be as much time as possible between passive flexion exercises (e.g. flexion in the morning and extension in the afternoon). This is the only way to avoid increased inflammation and swelling of the knee joint caused by repeated flexion and extension stimulation.