Pain-related threat and coordination in adults with chronic low back pain during a lifting task: A cross-sectional study.

Objectives: People with low back pain (LBP) exhibit altered coordination, possibly indicating guarded movement. The connection between these changes and pain-related threat remains unclear. We aimed to determine if pain-related threat was related to spinal coordination and variability, during a lifting task, in people with chronic LBP.

Methods: Participants were adults with chronic LBP (n = 47). Upper lumbar, lower lumbar, and hipkinematics were measured during 10crate lifting/lowering repetitions. Coordination and variability of the Hip-Lower Lumbar, and Lower Lumbar-Upper Lumbar joint pairs were calculated. Pain-related threat was measured using the Tampa Scale for Kinesiophobia, the Pain Catastrophizing Scale, and task-specific fear. Linear regression analyses tested the relationship between pain-related threat and coordination.

Results: Adding catastrophizing to our base model (sex) explained variance in Hip-Lower lumbar coordination (r change = 0.125, p = 0.013). General and task specific measures of fear were unrelated to coordination and variability at both joint pairs (r change < 0.064, p > 0.05). Exploratory t-tests revealed subgroups aligned with phenotypes of "tight" and "loose" control, where "tight" control was characterized by greater catastrophizing and disability.

Conclusion: Pain catastrophizing, but not measures of fear, was related to more in-phase ("tight") Hip-Lower Lumbar coordination during lifting/lowering. Considering this relationship based on subgroups may add clarity.