The reason why a lot of adults experience back pain might not have anything to do with their physical health but with the evolutionary past of humans suggests a study. The cause of back pain can be linked to humanity's evolutionary past according to new research from a team of bioarchaeologists at Simon Fraser University the University of Liverpool and the University of Sydney. The study was published in the journal- Evolution Medicine and Public Health. The study examines why some people are more susceptible to a particular stress fracture known as spondylolysis - a condition that often affects athletes.