1. As a classic strength exercise, sit-ups have existed for many years in competitive sports, national fitness and other fields. We know that the waist, abdomen and back are called the "core" of the human body, and they are the foundation to support and guarantee our daily activities such as walking, running, going up and down stairs, and carrying loads. Everyone should strengthen the strength of core muscles.
Secondly, the basic theory of sports human science and sports training tells us that the strength quality of human body can be divided into three categories, namely, maximum muscle strength, strength endurance and speed strength (explosive force). Among them, the maximum muscle strength and strength endurance are closely related to health, while the latter is mostly related to sports ability and competitive ability. For example, a helpless young man can hold or carry his family when they are in danger? Therefore, strength is the basis of ensuring human vitality.
Thirdly, the National Standard for Students' Physical Health (commonly known as "Physical Fitness Test") takes one-minute sit-ups as an index to evaluate students' strength and endurance, which has been in existence since the national survey and monitoring of students' physical health was carried out from 65438 to 0985. So far, the physical fitness of teenagers in China has been declining, including sit-ups of students of different ages.
Fourthly, the key point of sit-ups is that the human body is in the supine position, and the body gives priority to mobilizing the muscles of the anterior and lateral abdominal walls through the instructions issued by the central nervous system, that is, the abdominal muscles are motor muscles (commonly known as "strength muscles"), that is to say, doing sit-ups often can effectively develop the strength of the rectus abdominis, oblique abdominis, quadratus lumborum and other anterior abdominal muscles. The muscles located in the back, in the completion of this action, are exactly antagonistic muscles, which play an antagonistic role in sports. In other words, in order to successfully complete sit-ups, the muscles should be relaxed during the whole exercise, or the extensibility and elasticity of the back muscles determine the quality of the action. At the same time, in order to fix the pelvis and lower limbs (complete hip flexion and leg flexion), the muscles around the pelvic girdle, gluteal muscles, thighs and calves maintain moderate tension, which is theoretically called fixed muscles. It can be seen that sit-ups can only be completed with the cooperation of the above muscle groups.
Fifthly, the requirement of sit-ups in the National Standards for Students' Physical Fitness and Health is that "the subjects lie on their backs on soft cushions, with their legs slightly apart, their knees bent at 90 degrees, and their hands and fingers crossed behind their heads. The companion pressed his ankle to fix the lower limbs. " Therefore, in the "physical examination", students are not required to hold their heads with their hands. It is not clear how "hands crossed behind your head" means "hands holding your head". In the correct exercise, the function of hands is actually to fix the neck, which can also be understood as holding the neck and keeping the neck slightly forward to prevent the neck from stretching back (raising its head), causing back muscle tension and affecting the quality of exercise.
It can be seen that sit-ups with hands on their heads are a mistake in themselves. Life lies in sports, and sports should focus on science. So I still want to advise the media not to question the sit-ups in Physical Test with a wrong action. One-minute sit-ups in Physical Examination is a test action and an evaluation index. Its purpose is to examine students' strength and endurance level, and it should not be simply understood as an exercise or fitness action.
Sixthly, it should be pointed out that the cause of this discussion is the situation in Taiwan Province Province and the US military advocates "flat support" instead of sit-ups. First of all, due to incomplete evidence and information, it is impossible to judge whether sit-ups are the "culprit" that leads to vascular rupture and eventually paralysis. But medical common sense tells us that the pathological basis of general paralysis should be cervical spinal cord injury. The knowledge of human anatomy tells us that the cervical spinal cord is closely protected by the pia mater, dura mater, cervical vertebra and related joints, ligaments and muscle groups in the spinal canal. Can the pressure generated by holding your head in your hands "break through" these structures? In addition, nerves (such as cervical nerves) are damaged, which should cause symptoms such as hand numbness and neck discomfort.
Seventh, the basic theories of sports anatomy and sports biomechanics tell us that all body movements are rotation. Applying the lever principle to explain, whether our hands are placed directly behind our heads, crossed on our chests, or stretched on our sides, we can call them sit-ups. Different hand positions change the moment of resistance, or in layman's terms, we often feel laborious or relaxed when doing actions.