In daily life, we can often encounter such a situation: when you are walking alone in stride, a familiar greeting suddenly from behind, you can not help but turn your head sharply to look back; roadside a sudden tire burst sound, will also make you surprised, turn your head to see what, and so on. This unexpected sound or unexpected events to make subconscious head turn action, is the innate conditioned reflexes and stress reactions, sometimes it is difficult to avoid. But we have to point out here that this is a dangerous and easy to make the neck injury reaction, need people rational control and defuse. A sharp head turn may sprain the cervical spine or compress the vertebral artery. Under normal circumstances, the neck rotation is very limited. When the body is stationary, only by turning the neck to observe things on the side of the body, a normal person can only turn the neck about 30-40. The only way to expand the range of observation is to turn the body as a whole. In a sudden situation, people will instinctively make a very rapid stress reaction, before the body can adjust the posture, will turn the head sharply to the side or behind, the twisting force is often very large, more than the normal limit, at this time the cervical spine atlanto-occipital joint and atlanto-axial joint is very easy to damage, the surrounding ligaments and muscles may also be damaged at the same time, manifested as severe pain, neck function is obviously limited. If this happens, X-rays should be taken immediately’, and if there is a fracture or dislocation, the patient should be admitted to hospital for observation and cervical traction and other treatments to ensure the stability of the cervical spine. Experts point out that the blood supply to the brainstem and vestibular system comes from the vertebral artery, and the relationship between the vertebral artery and the cervical spine is extremely close, so its blood flow is susceptible to the impact of cervical spine injury. In the elderly, the vertebral artery is sclerotic to varying degrees, and the diameter of the canal becomes smaller. When the cervical spine is sharply turned, the vertebral artery can be suddenly compressed and the blood flow is sharply reduced, resulting in a sharp decrease in the blood flow supplying the brainstem, and the brainstem vestibular system ischemia and hypoxia, which can cause vertigo and balance disorders, and even falls and injuries. Therefore, for middle-aged and elderly people with bone degeneration, decalcification or osteoporosis, including postmenopausal women, special attention should be paid to avoid turning the head sharply, because there is a greater risk of spraining the neck. In order to prevent neck trauma, you need to learn the relevant knowledge, psychological training, calm and collected in case of emergencies, should be too calm, natural and gentle slow turn of the head, the body followed by the feet turn, adjust the gait, the body frontal turn to the direction of the incident, which is safer. Of course, to do so, there is a certain degree of difficulty, need to gradually accumulate experience. In addition, a sharp turn of the head may also twist the back. When an emergency occurs, young people tend to react faster, the body quickly turn in place, quickly adjust the posture, facing the scene, despite the sharp turn of the head, generally less accidental. But sometimes there will be a slow adjustment of the lower limbs, that is, the head turned, the upper body also turned, while the pelvis and both lower limbs remain in place, failing to convert the foothold direction, resulting in spinal twisting, upper and lower body in a different axis of the state, so that the lumbar torsion or shear force greatly increased, if the upper body inertia control is not appropriate, it may sprain the lumbar muscles or lumbar vertebrae, resulting in one side of the muscle fiber tear or small joint disorder. Once this happens, it will cause severe back pain, difficulty in standing upright, needing support, and even difficulty in lying down. The condition is aggravated by acute twisting of the spine in cases of original lumbar disc herniation. In this case, emergency treatment or hospitalization is required. A sharp head turn can also sprain the knee. If the accident is very dangerous and urgent, the body above the knee is twisted to one side when the person turns his head or body, and the lower leg below the knee is a beat slower, perhaps followed up later, but this late beat may also lead to injury to the medial and lateral collateral ligaments of one or both knees or rupture of the meniscus, especially in the middle-aged and elderly. Therefore, in case of an emergency that requires observation or evasion, the entire body should be turned quickly and in all directions, avoiding as much as possible an oblique or spiral twist of the longitudinal axis of the body, then, whether it is the neck, waist, or knee, the injury can be mostly avoided. It should be understood that the emergency head turn is a dangerous action, to be good at self-control, never be surrounded by the unexpected events “leading the nose”.