I cannot really think of a high level athlete that hurt himself with rep work, but many athletes come to mind that have had serious injuries with doing 1RM. Rob Kearney blew out his triceps on a max log lift. Brian Shaw destroyed his hamstring on a heavy deadlift. Laurence Shahlaei blew out his back on a 1RM deadlift. I've seen powerlifters blow out both quads on a heavy squat. Pecs on a heavy bench. etc, etc. Your body can handle rep work at lower weights if you progress properly. However, 1RMs are designed to test the absolute limit of your body, which is when you see the nasty injuries.I would say a high training volume at a high intensity (lot of limit triples and fives) is harder on your body than one rep max once a week.