High posterior neck pulldowns can be harmful in the following ways. First, it may cause the shoulder to be prone to injury. In the process of doing this kind of activity, the shoulder joint needs to be lifted, abducted and over-extended, at this time, the force on the shoulder, it is easy to cause some tendons, joint capsule and glenoid of the shoulder to have the corresponding pulling injury; Second, it may cause adverse effects on the cervical vertebrae and thoracic vertebrae of the patients. Because in the process of doing this kind of activity, the patient needs to continue to lower the head, and to continue to force, over time will cause some physiological curvature of the cervical and thoracic vertebrae changes, and then lead to degenerative changes in the spine. In addition, this kind of exercise sitting for a long time, there may cause the muscles on both sides of the thoracic spine, and gradually produce muscle spasms; Third, it may cause some dangers in the process of exercise. For example, in the exercise, because the patient is not able to judge the position of the equipment behind the head, if the patient is overly fatigued, then it is possible to cause the impact of the equipment and the head, or pinch the hair, which in turn caused some serious injuries.