Lumbar interspinous pressure pain threshold values for healthy young men and women and the effect of prolonged fully flexed lumbar sitting posture: An observational study

Abstract

Background: Low back pain (LBP) is a common condition with large burden worldwide. Exposure to prolonged sitting with a flexed lumbar posture has been suggested in the literature to be a potential risk factor for self-reported LBP. No study has previously investigated whether exposure to prolonged flexed sitting posture provokes discomfort/pain and decreased interspinous pressure pain thresholds for healthy young men and women without back pain, despite this being a suggested risk factor for LBP.

Aim: To investigate whether sitting in a prolonged flexed lumbar posture provokes discomfort and lowers interspinous pressure pain thresholds in the lumbar spine for healthy young men and women without previous LBP.

Methods: This is a an observational before and after study of 26 participants (13 men, 13 women) between 20-35 years old. Algometry was used to examine the pain threshold for pressure applied between spinous processes of the lumbar spine L1-L5. Pressure algometer measures were performed in prone before and after participants were instructed to sit in a fully flexed posture for a maximum of 15 min or until discomfort was experienced in the low back (Borg CR10 = 7/10). Wilcoxon signed-rank test was used for analyze values from the before and after test conditions. Mann-Whitney U test was used to investigate potential gender difference.

Results: Fully flexed lumbar spine sitting posture up to 15 min provoked temporary discomfort but the proportion of participants experiencing discomfort 7/10 in the low back was 62%. For all pain pressure threshold locations tested, there was a significant difference for the study population with moderate-large decreased (r = -0.56) pressure pain threshold after exposure to prolonged flexed sitting posture (P < 0.01). Comparisons between gender did not show any significant difference.

Conclusion: The result showed that exposure to fully flexed lumbar sitting posture for up to 15 min produced temporary discomfort in the low back in young healthy adults with no previous history of LBP and significantly reduced lumbar interspinous pressure pain thresholds. No gender-based differences were observed.

Keywords: Algometer; Low back pain; Pain mechanism; Pain pressure threshold; Posture; Spine.

Conflict of interest statement

Conflict-of-interest statement: The authors have no conflict of interests. The authors have no financial interests.

©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.

Figures

Figure 1

Algometer.

Figure 2

Seated position during the test.