Output list
Doctoral Thesis
Published 2020
This thesis explores pain sensitivity in adults with low back pain (LBP) before and after spinal manipulative therapy (SMT) using two quantitative sensory tests, pressure pain threshold (PPT) and temporal summation (TS). The focus was on short-term changes in PPT and TS after lumbar SMT and sham, and whether changes were clinically meaningful by exploring relationships with short-term symptomatic improvement in LBP after treatment and LBP trajectories. Additionally, differences in baseline PPT and TS based on LBP trajectory were investigated. An initial systematic review of adults with musculoskeletal pain found that PPT increases systemically at least in the short-term after SMT, but there is low quality evidence this is not different when compared to sham. There were not enough studies on TS to draw conclusions, and studies were generally of low quality. A subsequent high-quality randomised controlled trial was conducted, which found no differences in short-term change in PPT or TS after SMT compared to sham. Secondary analyses revealed that shoulder PPT increased immediately after intervention in people who had a significant improvement in LBP symptoms within 24 hours of receiving SMT or sham, compared to people who did not experience significant improvement. TS did not appear to be affected. Further secondary analyses revealed there were no differences in short-term change in PPT or TS after SMT or sham when comparing people with episodic or persistent LBP trajectories. There were no differences in baseline PPT and TS in adults without LBP compared to those with episodic LBP and persistent LBP. Overall, it appears that short-term hypoalgesia after lumbar SMT is no greater than after sham in adults with LBP. LBP trajectory may not be associated with differences in baseline pain sensitivity or post-treatment hypoalgesia. However, it may be that people with a short-term symptomatic improvement in LBP after treatment have selective short-term hypoalgesia in PPT but not TS. This may have also been a spurious finding.