Severe Pain Doing Chin-Ups

So I have no problem doing pull-ups, parallel grip pull-ups, etc.

However a supinated grip in about any exercise causes severe pain in the forearm. I can’t even hang in a chin-up grip position (hands facing me).

It feels like my forearm and bicep could snap at any time.

I occasionally get some bicep tendonitis, but I keep this at bay with lots of stretches, foam rolling, mobility drills ,etc.

But I can’t make any progress on the chin-up grip position. Even super light lat pulldowns with a chin-ups grip is painful.

I have tried googling this but had no luck. Anyone else have this problem, diagnose what it might be, or have suggestions on how to correct it?

I don’t know if it’s a forearm issue, a shoulder issue, or tight lats. All I know is it sucks not being able to do that motion.

Even bent over rows with a supinated grip is a big no no for me. Same feeling like my forearm could snap at any time.

Thanks for any input on the subject matter.

Sounds like bicep tendon problems. I pulled mine being stupid doing hanging leg raises and I relaxed my upper body as I was tried, then pulled my left bicep tendon.

Chin ups and anything to do with the bicep was a no no.

I fixed it with hammer curls for high reps, like super high.

When I first started to train after giving it a week to ice and relax, I could only use 5lbs and I worked up to 100 reps in one set. Once I could do 100 reps for 2 sets I moved up to 7 1/2lbs, and so on. It took a couple months to fully heal. I iced and did hot cold showers over the area and stretched and took naproxen at night.

This happened over a year ago. If I train hard now and if my recovery is crappy it gets sore but doesn’t become a problem.