Goal of the Study?
In this 2007 systematic literature review from the European Spine Journal1 the authors’ goals were twofold: (1) Review appropriate literature that examines the association between sitting and the report of LBP among the working population; and (2) Identify if there is an interaction between occupational LBP/sciatica and sitting in combination with whole-body vibration and/or awkward sitting postures.
Why are they doing this study?
In 2004, Lower Back Pain (LBP) was the leading cause of disability in persons younger than 45 years old and comprised approximately 40% of all compensation claims in the United States. Sitting has long been associated with LBP but there are also some co-exposure factors such as whole-body vibrations and awkward postures that greatly increase the odds ratio of having LBP. This study was an attempt to review the literature and quantify the effect of sitting for long periods and various co-exposure factors.
What was done?
Using a series of appropriate keywords, 155 articles were extracted from the MEDLINE, HEALTHSTAR and CINAHL databases. These studies were examined and the 24 articles that used or could calculate the Odds Ratio (OR) statistical measure were critically reviewed. The OR statistic is a measure of association between exposure (length of sitting, amount and magnitude of whole-body vibrations, normal versus awkward posture) and an outcome (LBP). The amount of sitting time and other co-exposure factors were determined from job titles and occupations using the US Department of Labor’s Occupational Information Network (ONET). The odds of reporting LBP were then associated with the various exposure factors.
What did they find?
In general, the literature reviewed indicated an increased risk of LBP and sciatica for individuals in occupations that required prolonged sitting (over ½ of working day). However, for all occupations, this risk factor increased significantly when awkward sitting and whole-body vibrations co-exposures were also present. Tractor drivers were 2.39 times more likely to report LBP than office workers. Helicopter pilots had the highest exposure to whole-body vibrations and also had the highest Odds Ratio. They were 6.6 times more likely to report LBP. The articles examined also found that the duration of exposure to whole-body vibration had a stronger association than its magnitude. In the author’s opinion, this suggested that the effect of vibration is cumulative in nature. Occupations that were exposed to frequent trunk flexion, bending and twisting were more likely to report LBP than occupations that only had a single awkward position factor.
Why do these findings matter?
The existence of the relationship between LBP and workplace factors has long been recognized. Among the occupational exposures identified, sitting is commonly cited as a risk factor, but the presence of co-exposure factors such as heavy physical work, heavy lifting, non-neutral postures and exposure to whole-body vibrations significantly increase the risk. Understanding LBP risk factors can lead to better ergonomic workplaces and mitigate the high rates of occupational LBP.
At Dynamic Disc Designs, we create and carefully craft anatomical models to help professionals explain contributing factors associated with occupational LBP such as heavy lifting, non-neutral postures and vibration to expose the anatomy at play. Education is the foundation of motivational learning to help make the associated changes to help reduce LBP.