Three-dimensional Kinematic Lumbar Spine Motion Analyses of Trunk Motion During Axial Rotation Activities

Abstract

Study Design: An experimental design was conducted to investigate kinematic changes in 3-dimensional trunk motions between subjects with and without chronic low back pain (LBP) while demonstrating axial rotation. Objectives: The purpose of this study was to compare 3-dimensional kinematic data for the upper and lower thorax and the lumbar spine from the axis of the core spine during axial rotation activities in the standing position while considering anthropometric factors in subjects with and without LBP. Summary of Background Data: Rotation of the trunk is associated with a large number of LBP cases and surrounding spinal tissue injuries. Methods: Fifteen subjects with chronic LBP (5 men, 10 women) and 15 subjects without LBP (9 men, 6 women) participated in this study. The outcome measures included kinematic data of actual trunk rotation angles for the upper and lower thorax and the lumbar regions relative to the core spine (spinal root) in sagittal, coronal, and transverse axes. Results: The spinal range of motion was significantly different for each spinal region (F = 240.25, P = 0.001) and axis (F = 213.91, P = 0.001). There was a significant interaction between the spinal region and the group (F = 4.34, P = 0.04). There was also a 3-way interaction with the spinal region, the axis, and the group (F = 11.04, P = 0.001). These results indicated that spinal region and axes are important to consider because the upper thorax demonstrated a significantly greater rotational displacement in subjects with chronic LBP. Among the anthropometric factors, age (F = 6.24, P = 0.02) interacted with the spinal region and the axis. Conclusions: Decreased spinal range of motion in older subjects might result in a stiffened spine in addition to possible poor proprioception from back injuries to passive structures in subjects with chronic LBP.