Bruin et al.¹ conducted a scoping review to assess the causal role of the relationship between loading and the onset of non-specific low back pain (NSLBP) and persistence of NSLBP (chronic low back pain (CLBP).

They conducted a literature search from 2010 to May of 2021. Causation (meaning load caused NSLBP) was established when evidence supported the Bradford Hill criteria (a set of guidelines for determining if an observed association is causal) of:

• Strength: How strong is the association between the two factors?
• Temporality: Does exposure always come before the onset of disease?
• Biological gradient: Is there a dose-response relationship?
• Experiment: Is there experimental evidence to support the association?
• Plausibility: How plausible is the association?

Results

They included twenty-two studies. Here are the highlights:

• There was no consistent support for a relationship between load and the occurrence of NSLBP. Further, it did not appear that more load increased the risk of NSLBP/CLBP.
• Half of the studies did not support that exposure to spinal load increased the incidence of or increased pain in NSLBP/CLBP.
• Half of the studies did not support load preceding NSLBP.
• No study supported plausible biological explanations to influence the relationship between load and NSLBP/CLBP, or that similar causes have similar effects on NSLBP.
• Nine of 10 studies did not support that load results in NSLBP or that relieving load reduces NSLBP/CLBP.

Conclusion

From this scoping review, there was insufficient evidence to support a causal relationship (meaning load causes low back pain) between loading and the onset and persistence of NSLBP/CLBP based on the BH criteria.

1. de Bruin LJE, Hoegh M, Greve C, Reneman MF. Insufficient Evidence for Load as the Primary Cause of Nonspecific (Chronic) Low Back Pain. A Scoping Review. J Orthop Sports Phys Ther. 2024;54(3):176-189. doi:10.2519/jospt.2024.11314