About one in ten Australians who have lumbar X-rays has a lumbosacral transitional vertebra. In a minority of them the anatomy causes persistent low back, buttock or hip pain, and the affected group is young: the published series have a mean age in the teens and twenties, and the reported athletes were sixteen and seventeen. The pain is invisible, comes and goes, looks like an ordinary sore back, and is usually named years after it begins.

This guide sets out, for PE teachers, coaches, school sport co-ordinators and school nurses, and for the sports physicians, physiotherapists and general practitioners who see adolescents from school and club sport, what the condition is and how often it causes pain in young people, how it sits beside spondylolysis, what imaging is available for under-16s under Medicare, what the reported adolescent cases show about treatment and return to sport, and how load is managed at the movement that loads the joint. A chapter for coaches and teachers can be read on its own. Two further chapters set out what patients report and what the treating clinicians will provide; an appendix gives a template note for the coach or teacher to send with the athlete.

Every clinical statement is referenced to the published evidence, and the notes at the end say what could and could not be verified.