N cord muscle isometric contraction – classical muscle strength of the lower extremity N cord muscle isometric contraction is the exercise of contraction and relaxation of the N cord muscle group in an isometric manner. The N cord muscle is a group of muscles in the posterior thigh whose main function of contraction is to flex the knee and posteriorly extend the hip joint. It is an important dynamic stabilizing structure to maintain knee stability, especially to prevent excessive anterior misalignment of the tibia. In the early stages of injury and surgery, a certain amount of braking protection is necessary to allow for safe tissue growth and healing, and to brake the joint from significant movement, and to practice the muscle so that the muscle contracts, it is necessary to use isometric muscle strength exercises. Isometric contraction is the process of muscle contraction, the change is only the internal tension of the muscle, the length of the muscle remains unchanged, is commonly known as “tense”. When the muscle contraction does not cause joint movement, the intensity is also very small. Therefore, it is very safe and gentle, and it is an exercise that can be started early after injury or surgery. Because the limbs and joints do not have to move, it is also called static contraction. There are many ways to practice the isometric contraction of the N cord muscle, and the most common one is the “straight leg press”. ”Straight leg press” specific exercise action is: leg straight flat on the bed or padded lower extremity with pillows, not bending the knee joint, just use the whole leg downward pressure on the bed or pillows. If it is not good to find the feeling of contraction of the muscles on the back of the thigh, you can use the heel of the foot to press down, so it is easier to find the feeling. But be careful, do not press down while bending the knee, with the knee bending action, it is not isometric contraction but isotonic contraction. Sometimes it doesn’t matter if there is a knee flexion or not, some injuries and surgeries are dangerous if the joint movement is absolutely avoided. Therefore, it is important to use a lighter force to find the feeling of muscle contraction first, and then gradually increase the force of the exercise. The illustration shows a sitting exercise, so it is easy to find the feeling of force. If the physical strength is poor, or pain is obvious, or there are other injuries can not sit up, lying down can also complete the action, practice to the back of the thigh N rope muscle group. Because it is a straight leg exercise, the knee joint does not have to bend to move. And is the whole leg in doing the action, there is no need for any equipment, so not only the hip, knee and ankle surgery can be practiced, even if the fracture of the patient, wearing a cast or splint and other support, you can also practice. Just be careful not to break the cast with bending movements. The scope of application is very wide! Specific exercises and volume: in the premise of not increasing the pain (note that it is not increased, just did not have surgery can not be completely painless, as long as the practice will not feel more pain will not be any danger), with as much force as possible under the tense thigh muscle for 5 seconds, and then relaxed count 1 time. Do 20-50 times per hour, and strive to reach 300-500 times per day, because the intensity of this exercise is very small, even if practiced 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 2 / 3 more than the maximum strength of the intensity of the downward pressure contraction N rope muscle, the number of Tens rule, that is, 10 seconds of contraction (of which 2 seconds gradually increase the strength, 6 seconds to maintain the force of contraction, 2 seconds gradually relaxed); 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. Can also be in the N rope muscle contraction tense after, has been maintaining this tension until very fatigue, relaxation rest count 1, rest 5 seconds after doing 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 do not only practice the leg that is injured or operated, but both legs should be practiced. Because of the functional rehabilitation exercises, there is a theory called cross-effect, a neurophysiological concept that refers to the fact that the force of one limb can lead to an increase in the strength of the muscles of the opposite limb being contracted at the same time.