Many doctors and patients find that the quadriceps muscle is the most obvious and fastest to atrophy after lower limb injury or surgery. The reason for this is that the quadriceps muscle is usually so heavily tasked that it often needs to support weight in order to do its job, so once it suddenly stops and is not stimulated by so much stress, it atrophies particularly dramatically. Therefore, early rehabilitation of the quadriceps is essential to restore function and prevent complications such as disuse muscle atrophy. Isometric contraction exercises for the quadriceps are tensing exercises for the muscles in front of the thigh. The so-called isometric contraction means that when the muscle is contracted, the length of the muscle remains the same and no movement of the joint is produced, only the internal tension of the muscle increases. 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 applicable, you can start to practice after the anesthesia subsides on the day of surgery. Even if the muscle or tendon itself is ruptured and stitched, gentle isometric muscle contraction relaxation exercises can be performed 2-3 days after the surgery. Lie on your back or sit on a bed with the injured or operated lower extremity extended 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 it will be a little harder to find the feeling of muscle contraction, and you need to experience it carefully for a few more attempts. After that, without increasing pain (note that it is not increasing, just had surgery is not possible completely painless, as long as the practice will not feel more pain will not be any danger), thigh muscle tense and then relax. The specific exercises are as follows: lying on your back or sitting on the bed, 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 harder, need to carefully experience more than a few attempts. After that, without increasing the pain (note that it is not increasing, it is impossible to be completely painless after the 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. In the knee joint under a small towel roll, so in the contraction of the muscle at the same time there is a tendency to extend the knee to press down the towel roll, it will be easy to find the feeling. (Note! It’s just a tendency, don’t really make the knee extension movement. Also, in order to see clearly, the towel roll is drawn relatively large, but in reality, as long as it is very small and convenient to find the feeling can be.) You can tense your muscles with as much force as possible for 5 seconds, then relax and count 1 time. Do 50-100 times per hour, and strive to reach 1000 times per 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 1 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. It is important to 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, some studies have shown that practicing through this crossover effect can increase the muscle strength of the leg on which the surgery was performed by 30%! The reason for practicing both legs at the same time is that this exercise can better promote the circulation of the entire lower limb, 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 ground and other more difficult exercises.