I was sparring with one of the guys at the gym who out weighs me by 50kg 6 months ago and he slipped and I got kneed in the tendon that attatches the inner thigh to the groin. It literally took me off my feet, my leg was spasming I stopped breathing and wanted to vomit. My trainer took me to hospital and I was there for 24hrs. It wasnt the genitals and no cup or jock of any sort would be able to prevent an injury there, but it still hasnt fully healed and probably never will. The ER room Doc was saying that its a rare kind of injury to get and nothing could have prevented it for me but for a guy wearing a box could make it worse because the edge of the box pushes on the tendon, it can be an ironic trade off wear the box to save your balls and risk your groin, or dont wear it and risk your balls to lessen potential damage to your groin. The physio was saying that alot of groin injuries are actually damage to the tendon and once its damaged it will give you problems for life. But apparently there are heaps of nerves there that connect directly to the spinal cord and its not pain that floors you its nerve interfearance the pain comes second.