Association of Pressure-Pain Threshold and Lumbar Lordosis in Subjects with and without Low Back Pain - A Case Control Study

Background: Physiotherapists perform movement testing in the assessment of patients with low back pain (LBP), to evaluate spinal mobility and symptom response. The purpose of this study was to investigate the correlation between degree of spinal curvature (SC) and pain elicited by posteroanterior (PA) forces in individuals with and without LBP.

Methods: The SC and pain response to PA force was measured in 60 age and gender matched subjects. The SC, comprising of lumbar lordotic angle (LLA) and sacral angle (SA), was measured from the sagittal view plain film radiograph. Pain response to PA force, i.e. pressure pain threshold (PPT), was measured at three spinous process levels using a pressure algometer, and statistically analysed.

Results: A statistically insignificant (p >0.5) negative correlation was noted between PPT values and SC at each test level within both the groups. The mean values of PPT tended to be lower (p >0.5) at individual test site in subjects with LBP compared to asymptomatic subjects. However, the mean LLA & SA in the LBP group was significantly lower compared to the other.

Conclusion: Although the degree of spinal curvature was significantly lesser in LBP subjects, the spinal PPT value in individuals with or without LBP may be influenced by factors other than this.