Sitting has been referred to as ‘the new smoking’…likely a stretch until sitting overtly kills millions, but what do we know about how it relates to low back pain (LBP)?
We know LBP is the leading cause of disability globally, and sitting for prolonged periods of time has been reported to be associated with LBP - we hear this from patients all the time!
It has been hypothesized that there are a number of theoretical pathways whereby nociception could be initiated during seated posture, as sitting involves flexed postures between 50-97% of end range of motion. When tissues move towards end range, they are subject to increased levels of stress and strain. Once mechanical forces, such as tension, compression and strain, applied to the spine surpass thresholds, this can trigger nociceptive signals. As many spinal structures have nociceptors, there are mechanical scenarios that provoke a pain experience. There are number of studies that confirm the biological plausibility of these pathways to pain: Stretching of posterior passive tissues of the spine instigates inflammatory and cytokine responses; pain is perceived at lower thresholds when inflammation is present; spinal flexion creates stress at the peripheral third of the disc (secondary to the posterior migration of the nucleus); and sustained low-level activation of the erector spinae muscles (during sitting) results in capillary compression and reduced oxygenation.
In experimental studies, perceived pain has been reported in young, healthy populations in response to sitting durations of greater than 1 hour, and sitting durations longer than 5 hours is predictive of recurrence of LBP. The data are unclear regarding occupational sitting as a risk factor for LBP, likely related to the high prevalence of both sitting and LBP, as well as the multifactorial nature of LBP. It is also noted that the more specifically an exposure is documented (i.e. occupational sitting), the better the ability to observe an association with risk.
Thus, the purpose of this systematic review was to summarize the evidence regarding the association between objectively measured sitting time and immediate increase in perceived LBP…enjoy!
THIS WEEK'S RESEARCH REVIEW: “Association Between Sitting & Low Back Pain”
This paper was published in JMPT (2020) and this Review is posted in Recent Reviews, Low Back Pain, Ergonomics and the 2021 Archive.
Sitting LBP