A positive pick-up test is mainly seen in lumbar spine tuberculosis, and the mechanism is that after the occurrence of tuberculosis in the lumbar vertebrae or discs, the local nerves are stimulated and the muscles become tense. In addition, when the patient is bent over with tuberculosis, in order to avoid lumbar pain, the body will find a posture for itself to avoid the pain triggered by the movement as much as possible, that is, when bending over, the vertical spinal muscles behind are in a strong spasm to prevent the bones, muscles, disc tissues or foci of tuberculosis in front from being unstable and producing pain when bending over, which is the human self This is the process of self-adaptation and self-regulation.