If you ask most people how to prevent back pain they will say: ‘Sit up straight and mind my back,’ because our parents have instilled this in us,” says Kieran O’ Sullivan, senior lecturer at the University of Limerick and lead physiotherapist at the sports spine centre in Aspetar hospital, Qatar. We are, says O’Sullivan, almost paranoid about posture. Yet the evidence linking posture and backache is surprisingly insubstantial.
Posture is defined by the world-renowned Cleveland Clinic as the position in which you hold your body upright against gravity while standing still or lying down. The word comes from the Latin ponere, which means to put or place.
In one study, researchers looked at the posture of teenagers and then tracked who developed back pain in adulthood. Teenagers with postural asymmetry, thoracic kyphosis (chest slumping) and lumbar lordosis (overly arched low lack) were no more likely to develop back pain than others with “better” posture.
Another study looked at increases in low back curve and pelvic angle due to pregnancy. The women with more postural distortion were no more likely to have back pain during the pregnancy. A systematic review of more than fifty four studies found no good evidence of a correlation between posture and pain. Leg length inequality seems to have no effect on back pain unless it is more than 20 mm (the average leg length difference is 5.2 mm). Hamstring and psoas tightness do not predict back pain.
Differences in postural control and gait have been identified between people with and without chronic low back pain (CLBP), this recent study suggests that people with mild to moderate CLBP present with similar standing postural control, and parameters of gait to a person with no symptoms. Treatments directed at influencing postural stability (eg, standing on a wobble board) or specific parameters of gait may be an unnecessary addition to a treatment programme. http://bmjopensem.bmj.com/content/4/1/e000286
In another study differences compared between postures for the back pain group and observations were contrasted with the changes previously reported for pain-free group. For comparison between groups normalised and non-normalised electromyography amplitudes attached to the muscles in the back were compared. Results said Individuals with a history of back pain demonstrated greater activity of the longissimus thoracis muscle in the long lordosis compared with the flat posture, but pain-free participants did not. Pain-free participants modulated lumbar multifidus activity with changes in lumbar curve, but people with a history of pain in prolonged sitting did not change multifidus activity between the long and short lordotic postures. https://www.sciencedirect.com/science/article/pii/S026800331830010X
So what does that mean?
Although some studies have found a correlation between back pain and posture, it is important to remember that correlation does not equal causation. It may be pain is causing the bad posture and not the other way around. This is a very likely possibility. People will spontaneously adopt different postural strategies when injected with a painful solution.
Based on the above, there is little evidence to support the idea that we can explain pain in reference to posture or that we can cure pain by trying to change posture.
O’Sullivan says that rather than focus on the right posture, the ability to vary it and shift easily may be more important:
“This brings us to the question why would anyone choose to correct their posture,” says Dr Eyal Lederman, an osteopath and honorary senior lecturer at University College London’s Institute of Orthopaedics and Musculoskeletal Science. “To date, all the research has shown that there is no relationship between any postural factors, including the shape and curves of the back, asymmetries and even the way we use our spine, to that of developing back pain. There is no relationship between sitting and developing back pain. Yes, if you already have back pain, you might feel it more when sitting; but it is not the cause of the back pain.” Lederman argues that we have evolved to be able to bend and lift: “These natural activities are safe and beneficial to our spinal health; we must stop being afraid of them.”
O’Sullivan’s advice is equally direct. “If you don’t have back pain, then do not give your posture one second’s thought – think about being healthy. Sleep deprivation and stress are more important than the lifting you do. Stress has a strong inflammatory role; it can make muscles tense. Most people don’t get that their back can become sore if they are sleep deprived.”
“Kids who get back pain do not have heavier bags, but research does show that if a child or their mother thinks their backpack is too heavy, then they will get back pain,” says O’Sullivan.
“Carrying something too heavy is not a risk – we keep reinforcing the idea that the back is very sensitive, but that is inaccurate. Kids are inactive and getting more overweight. Carrying a backpack is a way of getting physical activity.”
However, it is true that once you have back pain, then your posture may indeed affect it. Sitting for a long time is best avoided.
From an article in the Guardian Newspaper By Louisa Dillnier M