Bad back? Blame your ancient ape relatives
People with closer links to their ape ancestors may be more prone to a common cause of back pain, a study has shown.
Evidence suggests that individuals with chimpanzee-like vertebrae are at greater risk of suffering a slipped disc.
Bad backs may partly be the result of learning to run before we could walk in evolutionary terms, scientists believe.
The rapid evolution of our ability to walk upright on two legs appears to have left some people vulnerable to back trouble.
Lead scientist Dr Kimberly Plomp, from Simon Fraser University in Canada, said: "Our study is the first to use quantitative methods to uncover why humans are so commonly afflicted with back problems.
"The findings have potential implications for clinical research as they indicate why some individuals are more prone to back problems.
"This may help in preventative care by identifying individuals, such as athletes, who may be at risk of developing the condition."
Slipped disc, or "intervertebral disc herniation", affects between 20pc and 78pc of individuals.
It happens when cushioning pads of cartilage between vertebrae split and release a gel-like substance that puts pressure on spinal nerves.
The cause is not always clear but age is thought to be a factor.
While humans habitually amble on two feet, chimps mostly walk on their knuckles while orangutans use all four limbs to climb trees.