Effects of fear of movement on spine velocity and acceleration after recovery from low back pain

Abstract

Study design: A cross-sectional assessment of the association between pain-related fear and joint motions and their higher order derivatives in 88 participants recently recovered from an episode of low back pain.

Objective: To determine how the psychological construct of pain-related fear maps to motor behavior in standardized reaching tasks.

Summary of background data: Pain-related fear is a significant predictor of avoidance behavior and occupational disability in individuals with low back pain. However, it is not currently known how pain-related fear maps to motor behavior.

Methods: Participants were tested at 4 weeks (+/-2 weeks) after resolution of a recent episode of back pain. Participants performed reaching tasks at comfortable and fast-paced movement speeds to 3 targets (high, middle, low) located in a midsagittal plane. Three-dimensional joint motions of the thoracic spine, lumbar spine, and hip were recorded using an electromagnetic tracking device. Group differences in joint excursions, peak velocities, and accelerations were assessed using 2-group (high pain-related fear, low pain-related fear) x 2-hand (left, right) x 2-movement speed (comfortable-pace, fast-pace) x 3-target height (high, middle, low) multivariate analyses of variances.

Results: Individuals with high pain-related fear had smaller peak velocities and accelerations of the lumbar spine and hip joints for the fast-pace reaching trials.

Conclusion: The present study provides important evidence that pain-related fear is a robust construct that clearly maps on to differences in peak velocity and acceleration of the lumbar spine even after resolution of back pain.