Football players, artistic gymnasts and rhythmic gymnasts make up most of the 10-15% of young athletes that have low back pain. Low back pain patterns are different in young athletes than adults. Pars interarticularis injuries are most common and only 11% are disc related in young athletes, as compared with 48% of adult injuries being disc related. Spondylolysis is a defect in the pars interarticularis, a stress fracture from repetitive extentions and torsion of the spine. Up to 47% of young athletes with low back pain are reported to have spondylolysis occurring most often at the L5 and on the left side.
Source: Sports Health: A Multidisciplinary Approach May/June 2009