Different Spatial Characteristic Changes in Lumbopelvic Kinematics Before and After Fatigue: Comparison Between...

The lumbopelvic region plays a pivotal role in enabling various functional activities. This study quantified and compared the kinematic changes between healthy individuals and patients with recurrent low back pain (LBP) in both rested and fatigued states to gain insight into the kinematic adaptation and mechanisms underlying kinematic variations that occur in the presence of these factors.

Participants were divided into two groups: the LBP (n = 23) and healthy control groups (n = 19). Dynamic lumbopelvic measurements were taken using a biplane radiography image system while the participants performed weight-bearing forward-backward bending before and after fatigue. All lumbopelvic kinematics were described as the three-dimensional motion of the vertebra relative to the pelvis and were measured at normalized time intervals from maximum extension to approximately 45° of flexion.

Repetitive lifting- and lowering-induced fatigue significantly affected lumbopelvic kinematics in the anterior/posterior translation (mm) and rotation around the z-axis in both healthy individuals and patients with LBP (p < 0.05). In healthy individuals, significant differences occurred in approximately 13-83% of the forward-backward bending cycle (0-100%), whereas, in patients with LBP, significant differences mainly occurred in 61-93% of the cycle (p < 0.01).

The lumbopelvic kinematic changes observed in both LBP patients and healthy individuals after fatigue may indicate protective compensation or vulnerability and could play a role in LBP dysfunction.