1.Tsinghua University;2.Department of Orthopedics,Shenzhen Second People’s Hospital,Shenzhen,China National Research Center for Rehabilitation Technical Aids,Beijing,China Department of Orthopedics,Shenzhen Second People’s Hospital,Shenzhen,China;3.Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen
Objective: Compare the kinematic differences between patients with lumbar disc herniation (LDH) and healthy people during three daily activities by a refined trunk model compose of different lumbar segments, lumped thoracic and pelvis. Compare the trunk refined model and trunk simplified model adopting the whole lumbar segment and discuss the necessity of using the refined trunk model for the kinematic analysis of LDH patients. Method：Motion capture system NDI was used to collect kinematic parameters of each segment of 15 healthy men and 7 male LDH patients during level walking, trunk flexion, and contralateral pickup, then compare the kinematic differences between patients and healthy people by the two models respectively. Result：During level walking, the patients increased the rotation of the thoracic segment and pelvis. No significant change in the motion angle of whole lumbar segment but the rotation angle of the L4L5 segment was significantly reduced; during trunk flexion, the flexion angle of the patients' all lumbar segments was reduced by varying degrees, and the flexion angle of the L3L4 segment was significantly different from that of healthy people; during contralateral pickup, the performance on the sagittal plane is similar to that of flexion. However, the lateral bending angle of patients' L3L4 segment and L4L5 segment was significantly lower than that in the healthy people. Conclusion：LDH Patients mainly restrict the motion of injured lumbar spine segments in daily activities. In some motions, only refined model can discover abnormal motion of the injured lumbar segment. Therefore, it is necessary to subdivide the lumbar spine into 5 independent segments when analyze the kinematic character of LDH patients.