Case series of pectoralis major rupture requiring operative intervention sustained on the Royal Marines ‘Tarzan’ assault course

We present (with intra-operative imaging) four patients who sustained pectoralis major (PM) ruptures on the same piece of equipment of the ‘Tarzan’ assault course at the Commando Training Centre, Royal Marines (CTCRM). Recruits jump at running pace, carrying 21 lbs of equipment and a weapon (8 lbs) across a 6-feet gap onto a vertical cargo-net. The recruits punch horizontally through the net, before adducting their arm to catch themselves, and all weight, on their axilla. All patients presented with immediate pain and reduced function. Two had ruptures demonstrated on magnetic resonance imaging, one on an ultrasound scan and one via clinical examination. All four patients were found, at operation, to have sustained type IIIE injuries. All patients underwent PM repair using a unicortical button fixation and had an uneventful immediate postoperative course. Patient 1 left Royal Marines training after the injury (out of choice; not because of failure to rehabilitate). All other patients are under active rehabilitation, hoping to return to training. Review of 10 years of records at CTCRM reveal no documented PM rupture prior to our first case in October 2013. There has been no change to the obstacle or technique used and all patients deny the use of steroids.