Spondylolysis and spondylolisthesis in military parachutists.

This paper reports on three cases of symptomatic low back pain in three paratroopers in association with bilateral L5 spondylolysis and L5 on S1 spondylolisthesis. The controversy regarding the etiology of this lesion as well as the problems of establishing causality when associated with parachuting injuries are discussed. These cases raise the issue of whether routine lumbar spine roentgenography should be performed as part of the pre-course medical screening prior to an individual undertaking basic parachutist training, and stress the need for further study of the relevance of these lesions in military parachuting.