Influence of weight-bearing on the 3D movement of lumbar facet joints in sitting position

Abstract

Abstract Background Recognizing the motion characteristics of lumbar facet joints is helpful to prevent and treat lumbar degenerative diseases. At present, the research on the motion of lumbar facet joints is mainly focus on motion characteristics of lumbar facet joints without weight-bearing. However, there is no related research on whether weight-bearing has an effect on facet joints in sitting posture. The purpose of this study was to analyze the motion characteristics of lumbar facet joints and to observe the effect of weight-bearing on lumbar facet joints in sitting position. Methods Ten normal subjects (5 males and 5 females) were recruited and scanned by CT, and their lumbar 3D models were reconstructed by software. The images of flexion and extension of lumbar facet joints in sitting position were collected without weight-bearing and weight-bearing 10kg, and the 2D model was constructed by software. The 2D-3D model was matched to restore the flexion and extension motion changes of the subjects' lumbar spine in the sitting position, and the relevant data of facet joinets were collected. Results In the L3/4 segment, After weight loading, the displacement of the left facet joint in the X axis became larger, while that in the Y axis and Z axis became smaller. the displacement of the right facet joint in the X axis and Y axis became larger, and the Z axis displacement became smaller. The rotation angle of bilateral facet joints also became smaller. In the L4/5 segment, after loading, the displacement of the X、Y、Z axis displacement of both sides becomes larger, while the rotation angle of α and β increases, while the rotation angle of γ decreases. In the L5/S1 segment, the displacement of the X、Y、Z axis on the left side becomes smaller. The displacement of the X、Y axis on the right side becomes smaller, while the displacement on the Z axis becomes larger. The rotation angle of α and γ becomes larger, and the rotation angle of the β axis becomes smaller. Conclusion when sitting, the flexion and extension distance and rotational displacement of lumbar facet joints are not affected by weight-bearing. In addition, there is asymmetry in the movement of the left and right facet joints, and the weight-bearing has no effect on the asymmetry of the motion.