Quadriceps (the muscle group in front of the thigh): the role of the lower limb is crucial, many movements of the lower limb are dependent on the strength of the quadriceps muscle to complete, quadriceps muscle strength is not enough to make many of the necessary functions of daily life, such as walking, is affected. However, after lower limb injury or surgery, the quadriceps muscle is the most obvious and fastest to atrophy. Therefore, early rehabilitation of the quadriceps is essential to restore function and prevent complications such as disuse atrophy. The problem is that in the early stages of injury and surgery, a certain amount of braking protection is necessary to allow the tissue to grow and heal safely, and to brake the joint from significant movement, and to practice the muscle to allow it to contract, it is necessary to use isometric muscle exercises. Simply put, quadriceps isometric contraction exercises are tensing exercises for the muscle groups in front of the thigh. By isometric contraction, I mean that the muscle is contracting with the same length of the muscle, which does not produce movement of the joint, but only an increase in tension within the muscle. It is also called a static contraction because the limb and joints do not have to move. It is the most commonly used muscle strength exercise in the early post-injury and post-surgery period to maintain muscle tone and maintain or increase muscle strength. The quadriceps isometric contraction exercise is a very safe exercise because you don’t have to move your lower limbs or joints. At the same time, the size of the force can be adjusted and controlled at any time, you can use a little more force, fatigue or pain can also reduce the force or even stop at any time. So for ankle, knee, hip, lower limb fracture, joint replacement and other kinds of surgery is suitable, the day after the anesthesia subsides, you can start to practice. Even if the muscle or tendon itself is ruptured and sutured, gentle isometric muscle contraction relaxation exercises can be performed 2-3 days after surgery. Doing these isometric exercises in the early post-injury and post-surgery period not only improves the neuromuscular control of the quadriceps muscle (avoiding muscle “dysfunction”, that is, forgetting how to control the muscle after a long period of immobility, when the mind is thinking, but the leg just won’t move), and minimizes disuse muscle atrophy of the quadriceps. At the same time there is a benefit of the greatest by-product, is that in the process of muscle contraction can pull the patella upward movement, to prevent the knee surgery after the suprapatellar capsule adhesions, is to prevent the braking caused by adhesions of the knee joint can not be wrist flexion. Of course, there is also a lot of role in promoting circulation to reduce swelling and joint effusion and so on. The specific exercises are as follows: lie on your back or sit on the bed with the injured or operated lower limb straight and flat on the bed. Some lower limbs will be fixed in a slightly bent position after surgery, you can also do this exercise, but find the feeling of muscle contraction will be a little more difficult, need to carefully experience a few more attempts. After that, under the premise of not increasing the pain (note that it is not increasing, it is impossible to be completely pain-free just after surgery, as long as you do not feel more pain after the exercise there is no danger), the thigh muscles are tense and then relaxed. If it is not easy to find the feeling of muscle contraction when you first start practicing, you can do as shown in the diagram below. Under the knee joint pad a small towel roll, so that in the contraction of the muscle at the same time there is a tendency to extend the knee to press down the towel roll action, it will be easy to find the feeling. (Note! Just the trend, do not really make the knee extension action. Also, in order to see clearly, the towel roll is drawn relatively large, but in reality, as long as it is small and convenient to find the feeling.) You can tense the muscles with as much force as possible for 5 seconds, and then relax to count 1 time. Do 50-100 times per hour, and strive to reach 1000 times a day, because the intensity of this exercise is very small, even if you practice many times a day can only slow down the rate of muscle atrophy, so the number mentioned above is not much! You can also use more than 2 / 3 maximum strength to contract the quadriceps, the number of Tens rule, that is, 10 seconds of contraction (2 seconds to gradually increase the strength, 6 seconds to maintain the force of contraction, 2 seconds to gradually relax); after 10 seconds of rest; each repeat 10 times for a group; 10 groups of continuous practice. This practice 3-5 times a day, almost also or 500-1000 times. You can also contract the quadriceps muscle after tensing, keep this tension until very fatigue, relax and rest count 1 time, rest 5 seconds after doing it again, so the cycle of 10 times for 1 group, practice 3-5 groups per day, or every hour practice 1 group. Note that: when practicing not only the leg that was operated on, but both legs should be practiced. Because there is a theory in rehabilitative functional exercises, called the crossover effect, a neurophysiological concept that refers to the fact that exertion of one limb can lead to an increase in the strength of the muscles on the opposite limb that are contracting at the same time. So in the early rehabilitation functional exercises after injury or surgery, to do isometric contraction exercises for the quadriceps muscles of both legs at the same time, there are studies that show that practicing through this crossover effect can increase the muscle strength of the leg on the side of surgery by 30%! Whether it works that well or not, one family’s opinion may not be enough to prove it, but it does work, for sure. There are also reasons for practicing both legs at the same time: such exercises can better promote circulation throughout the lower extremity, while the strength of the healthy side of the leg does not decline due to bed rest, and can better help support and stabilize the body and protect the injured leg during subsequent walking on the floor and other more difficult exercises.