A 26-year-old man who was a military parachutist, experienced a parachuting accident with collapse of his parachute at a height of 600 ft. The particular biomechanics of his impact were favourable. He sustained an L3 wedge compression fracture and pubic symphyseal diastasis. He recovered fully over 10 months and was able to return to full duties, including parachuting. The biomechanics of human impact during vertical deceleration and the associated injuries are discussed in detail with reference to this case and parachutists in general. The relevance of standard parachuting drills and the importance of properly executed malfuction drills are addressed.

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.