The purpose of this study was to explore the characteristic of trunk angle and flexibility of spine in lumbar disc herniation (LDH) patients, non-specific low back pain (LBP) patients and healthy subjects during bending exercises. 35 patients with LDH, 32 patients with non-specific LBP and 24 healthy controls participated in this experiment, volunteered to stand, then bend forward as far as possible, stay fully flexed, and return to stand with performing five cycles. As an indirect measure of spine performance, the trunk angle captured using motion sensors. We estimated the degree of spine activity by comparing the trunk angle between LDH, LBP and healthy controls in roll, pitch and yaw planes, respectively. As results, the significant differences between LDH, LBP and healthy controls in the female group of volunteers was found for trunk angle of three planes (p< 0.05). Between female and male had differences of trunk angle in LDH, LBP and healthy controls, respectively. Combined the most frequently used visual analog scale (VAS) for the pain of clinical research to explore the characteristic of subjective response of the patient on trunk angle by objective measurement, which might be a useful tool to reflect the abnormal degree of the spine in the diagnosis of spine and rehabilitation. In summary, these results advised LDH and LBP patients to do strength training reasonably to restore lumbar muscle function and assist in stabilizing the spine.