Many patients believe the weather impacts their pain symptoms, say researchers, but their study published today has revealed that the weather does not have any influence over lower back pain – except for a “clinically unimportant” association with increases in wind speed.
The findings are presented in the American College of Rheumatology’s journal Arthritis Care & Research. The analyzed weather conditions affecting the Australian study population included:
- Air pressure
- Wind direction
None of these factors was associated with the onset of symptoms. Only higher wind speeds and gusts of wind could be linked, with a “weak association,” to episodes of lower back pain.
An increase in wind speed of 11 kph (around 8 mph) led to a higher risk that pain would come on 24 hours later, and gusts increasing by 14 kph (around 7 mph) had a similar effect – but the magnitude of this was small, “only a trivial increase in the risk.”
The authors of the study wanted to provide robust data against what they say is a poor-quality background of research. Previous studies claiming an association with the weather failed to examine the environmental conditions independently of the patients’ pain complaints.
One of the authors, Dr. Daniel Steffens, of the George Institute for Global Health at the University of Sydney, Australia, says:
“Many patients believe that weather impacts their pain symptoms. However, there are few robust studies investigating weather and pain, specifically research that does not rely on patient recall of the weather.”
The researchers instead used objective reports of the weather at the time of the lower back pain, from weather data collected by the Australian Bureau of Meteorology.
Further, neither the 993 people with back pain nor the back pain assessors in the study knew the specific reason for recording the symptoms – they were “blinded” to the hypothesis, so that there would be no added influence on the results from any beliefs they held about the effects of the weather on symptoms.
As a control, to help account for the effect of pure chance on any links found in the study, the weather at the time of reported symptoms was compared with the conditions one week and one month before the onset of pain.
The myth-busting results, say the researchers, should lead to more work to clarify what effect the weather may or may not have on wider medical conditions. Dr. Steffens says:
“Our findings refute previously held beliefs that certain common weather conditions increase risk of lower back pain.
Elucidating the true influence of the weather on lower back pain is important if recent statistics are considered. A report published in the Annals of the Rheumatic Diseases in March 2014, based on the study known as Global Burden of Disease 2010, found that lower back pain was the number one cause of disability worldwide.
If weather is not to blame for lower back pain, other selected examples of research appearing in the news recently point to the brain producing different responses in those people who go on to have chronic back pain following an injury.
Chronic pain was predicted by the brain’s emotional response, according to research with functional MRI scans of back injury patients published in Nature Neuroscience in July 2012.
MRI scans were also used to conclude in a Pain paper from September 2013 that brain white matter abnormalities were a predictor of chronic pain for people who had had a lower back injury.