The quadriceps is the most important muscle group of our human thighs. Firstly, it is not only responsible for our main strength when walking, walking up and down stairs, squatting and other movements, but also for the stability of our knee joints, especially the patella and the anterior-posterior stability of the knee joint. Secondly, if there is significant atrophy of the quadriceps, most commonly and most importantly the medial head (the quadriceps is divided into four heads: medial, lateral, intermediate and rectus femoris), it is likely to lead to imbalances in knee balance, strength, patellofemoral stability and other aspects of function, which can further lead to degenerative changes in the knee (like getting old early) and many other related diseases. Therefore, it is a very important thing to maintain the normal muscle state and strength of the quadriceps. Ordinary people should practice regularly to maintain the normal functions we need in our daily lives such as walking up and down stairs, squatting, etc. People with knee diseases should practice even more to enhance the protection and motor function of the knee joint, which can also promote the recovery of knee injuries. So, how do you practice? The following is a summary: First, the most common and operable is the static squat exercise. The squat is a method of exercise that is suitable for the general population, especially the elderly, and is mainly for exercising the muscle strength of the quadriceps. It is reasonable and easy to adhere to because it uses a stationary exercise method, so it does not increase joint damage and generally does not cause pain. In addition, this way can be exercised anywhere and does not require auxiliary equipment, so it is very feasible. Not only can it cure the disease, it is also a very good exercise method for those who usually do not exercise much to improve their muscle strength and ability. Applicable conditions: patellar tenderness, patellofemoral cartilage injury, knee osteoarthritis (especially poor squatting ability patients), painful lesions on the upper and lower poles of the patella, squatting power weak or easy to pain patients, people who usually exercise little want to strengthen the thigh muscle strength, joint injury in the early to mid-term recovery patients and so on. Specific exercises: 1, the main points of action: back against the wall, feet apart, and shoulder width, and gradually reach forward, and the body’s center of gravity between the formation of a certain distance, about 40-50 centimeters. At this point, the body has been presented with a squatting posture, so that the long axis of the lower leg and the ground vertical. The angle between the thigh and calf should not be less than 90 degrees. Because the squat is too deep, it will significantly increase the pressure on the patellofemoral joint, but also does not produce a strong exercise effect on thigh muscle strength. 2, the number of times and time requirements: generally each squat to the end of an inability to adhere to, rest 1-2 minutes, and then repeat. Repeat 3-6 times a day for the best. 3, special attention: the angle of the squat is very delicate, because the maintenance of the posture of the muscles have a “spillover effect”, simply put, each part of the muscle only in a certain range of angles to maintain the role of posture. Therefore, it is best to do squats at different angles. For example, 30, 60, 90 degrees 3 angles, the effect will be better. Squatting is best done at an angle that does not cause significant pain. Otherwise, improper practice will aggravate the injury. Secondly, it is also very practical and easy to operate the leg tensing exercise. That is, when the knee is straight (sitting, standing, lying can do) active contraction of the quadriceps muscle, so that it is tense, hold for 5 seconds, and then relax for 2 seconds, and so on. It is best to do enough 2000 times a day. It is not required to do it all at once, it can be done in several times, with the same effect. The left arrow is not needed in this picture, the right arrow points to the part that is the quadriceps (from the outer thigh), please note that the performance of this muscle group contraction is the quadriceps muscle resistance exercises. Mainly the following actions: 1, straight leg lift: lying on the bed (must lie, if sitting practice, to not easy to hurt), tied a sandbag in the ankle, the weight can be determined according to their strength and feeling, no fixed requirements. General 1-3 kg can be. Straight position will lift the whole leg, so that the angle between the leg and the bed at about 30 degrees is the best. Hold for 5 seconds, then lower for 2-3 seconds, and so on. Do 3-4 sets per day, and the indicator that each set of exercises is effective is that the muscles feel fatigued enough. Then you can rest 1-2 minutes, and then repeat. 2, knee extension resistance: sitting on the edge of the bed or chair, the ankle tied sandbags. From a relaxed flexed knee position until the knee is straightened with force. Of course, the most important exercise is that the effective range of motion of the medial head is within 30 degrees of extension, so if the focus is on the medial head, the last 30 degrees can be practiced primarily. The exercise requires the same straight leg raise.