A while ago I was going curls with the z bar with enough weight that it was pretty difficult to do. I may have dropped/slammed the bar onto the preacher rack and that hurt my forearm a little bit. This was about a month ago or more.
Yesterday I was doing curls with dumbells with much lesser weight and when I put it down and released it, i could feel the pain in the forearm again. I’ve taking it slow, if do hammer curls instead which don’t hurt.
try bent over rows withpalms facing out for a while, if done with good form they are pretty difficult. If these hurt to do too you should drop curls for a while.
Injury diagnosis via the Internet is always a guess, but…
You may have hyperextended the elbow, since it happened on the preacher curl. I’d back of the direct bicep work for a while, and ice it down after any pulling work.
Since it happened a month ago and it’s still causing pain/interfering with your usual workout, having a professional look at it would be a good idea.
Rub some dirt on it.