The global burden of low back pain – more than just an irritation

Is this really a public health issue? Am I just tired of writing about Ebola and traditional non-communicable diseases that I’ve decided to make low back pain, something that we’ve all experienced, into a public health problem?
Maybe. Then again, did you know that low back pain is the leading cause of activity limitation and work absence throughout much of the world? In the US, it is the most common cause of job-related disability and a leading contributor to missed work days – approximately 149 million work days are lost every year because of low back pain, with total costs estimated to be US$100-200 billion a year. Low back pain is also the most frequently reported pain condition among adult Americans.
In a recent global burden of disease study (that is, a study looking at the burden of all disease in the world), low back pain ranked sixth in terms of overall burden of disease – right below stroke and HIV/AIDS, and above 291 other conditions surveyed, including road injury, depression, diabetes, TB, and all mental health conditions and cancers.
To get technical just for a moment, the burden of disease is measured by disability-adjusted life years (DALYs), which are calculated by combining years of life lost (YLL) due to premature mortality, and years lived with disability (YLD). Because nobody dies from low back pain, when you look just at the YLD, it actually ranks number one – ie the greatest contributor to disability in the entire world.
The causes are very hard to pin down
Yet it’s rarely discussed, mostly because it is incredibly complicated, and the causes of chronic back pain are very heterogeneous. Of course there are the obvious causes, such as trauma from car crashes or sporting injuries, but these do not account for the burden of disease we’re seeing here. Clearly this is because it is a complex condition, caused by many different factors, many simply to do with the fact that we are one of the first and only species of our kind to walk on two legs, which comes at a cost to the part of the body where the load is the heaviest – the lower back.
Unfortunately, it’s difficult to get any more scientific consensus on what causes it, or what we can do. Although the symptoms can appear very similar, there are many different causes and triggers – some genetic, some environmental, some postural, some as a consequence of another injury or disease. Although posture and alignment have long been associated with back pain, it hasn’t been possible to find a strong scientific correlation, partly because the types and causes are so varied.
That doesn’t mean it is impossible to identify some common factors, even if they are only common to a small segment of the population experiencing lower back pain. As with cancer, we may one day learn that there are many different types of lower back pain, caused and triggered by different things in different people.
Does that mean there is nothing we can do but be thankful for the walks we take?
For you personally, maybe, so go ask your doctor. But as a public health lawyer wondering whether there is anything we can do from a population-based prevention perspective, I looked for risk factors and data that may help us address at least some part of this problem.
Though these are very difficult to identify, a study has shown that 37% of all low back pain worldwide is attributable to occupation, which is a very significant part of the burden, some of which can presumably be prevented.
Other than that, the main risk factors for low back pain seem to be age, fitness level, weight gain and obesity, occupational risk factors, mental health and backpack overload in children. This makes sense – most of us go about our bi-pedal lives without realizing how much pressure we are putting on our back, relying on our spine to support our head and balance our weight directly over our hip joints and lower limbs.
How often do you think about your alignment?
Even in the absence of clear scientific consensus about the role of posture, the anecdotal evidence is growing and preventative postural interventions are being recommended by medical professionals as well as institutions such as the Harvard Medical School, Mayo clinic, and the UK national health service. Even if we don’t know when and why, it is almost a truism to say that posture and alignment does contribute to the back pain of a certain segment of the population, which given the size of this problem, is likely to be a significant number of people.
In the absence of injury (or strict piano lessons), most of us don’t turn our minds to how we are standing, sitting or walking. As a child, I do remember occasionally being called out for “bad posture” or told to have a “straight back”. I also remember having no real idea of what that meant beyond trying to pull my shoulders back, stick my chest out, then feeling annoyed and uncomfortable.
In the workplace, I was always offered different ‘ergonomic’ chairs, and within a few hours, would still find myself (and most of my colleagues) slumped into all sorts of strange but seemingly comfortable positions.
Our work environment plays a significant role in many other public health burdens, such as sedentary lifestyles leading to obesity, cardiovascular disease and mental health. The impacts of long periods of sitting, have recently gained a lot of attention for increasing the risk for all sorts of health consequences such diabetes and weight gain, leading some workplaces to adopt standing or treadmill desks. Which is also great for addressing back pain, because we know that weight gain and physical inactivity are risk factors.
But given the public health burden of low back pain, we should also be ensuring to the extent we can that we are teaching people to stand and sit appropriately. In my experience, training was rarely provided in workplaces that instituted standing desks, and I would constantly see colleagues slouching or sinking into their hips or lower back while engrossed in work.
A daunting problem that can’t be ignored
While so much attention is being paid to reducing obesity and other chronic disease, this is just one example of how simple it could be to include what little we do know about low back pain into broader preventative health strategies. For example, education campaigns that encourage children and adults to be more active can also educate about posture and alignment. Workplaces that spend money on special chairs or standing desks can invest that little bit more to teach people how to actually sit and stand in the best ways possible.
Given the magnitude and public health impact of the problem, the public health community should be doing more to identify common risk factors, different causes, treatments and especially preventative measures. At the same time, while we are investing heavily in the brain sciences through the US BRAIN Initiative, I would call on neuroscientists to help in identifying at least some of the causes of this pain disorder. Some of these may be high-tech research and interventions, but there is also much that neuroscience can offer in determining the role that ‘low-tech’ or lifestyle factors such as posture, exercise and even diet may play.
The complexity of the problem makes it incredibly daunting. But that is no reason to leave the greatest contributor to disability in the world out of the public health agenda.