Martin just had one small bruise on the ring finger of his left hand, that’s what’s provoking my curiosity.
Now as for Martin. I doubt he was trained in their use. Nor are most ganstas. Look up kangraoo fighting and thats the typical routine. He probably used his fists. I don't think he used elbows, I just put that out there for consideration.
Now as for their use in general. Sure, throw a punch. Break it on top of someones head. I've been combat sports for years so I also have a opinion on the matter. I've use elbows for years, and I've never had a problem. But, everyone is different.