People who suffer from back pain have been dealt a lousy hand by evolution and might be more comfortable walking on their knuckles like our closest relatives, chimpanzees, according to Canadian, Scottish, and Icelandic researchers. Their study found that lower back pain sufferers have a lesion called a "Schmorl's node" in the disc between the bones of the spine, and their spines are closer in shape to those of chimpanzees than of fellow humans who don't suffer disc problems, the BBC reports. The researchers, whose study is published in the journal BMC Evolutionary Biology, used the skeletons of orangutans, chimpanzees, and ancient humans for comparison.
The spines of our ancestors changed as we started to walk on two legs, but "evolution is not perfect and some vertebral characteristics, such as the ones we identified as being similar to chimpanzees, may have remained within the human 'blueprint' and result in some people having vertebrae that are less able to withstand the pressures of bipedal walking," one of the researchers explains in a University of Aberdeen press release. "In short, our study suggests that the pathological vertebrae of some people may be less well adapted for walking upright." The researchers say their findings could help the study of diseases like arthritis and identify people at future risk of back problems. (There's also an evolutionary reason why men like curvy women.)