[Noah930]

Sounds like a torn distal biceps tendon, like Tobra said. Typically happens in men in their 40s and 50s. Sudden load of stress on the arm, like catching a tripping person or falling 55-gallon drum filled with liquid. There'll often be a pop, followed by pain in the antecubital fossa (the part of the elbow opposite the pointy part where you "elbow" someone). There might also be some pain, swelling, and bruising on the inside of the elbow (the side that brushes up against your ribcage).

It doesn't have to be fixed (which is done surgically). The biceps' major function is not elbow flexion, like we commonly think; rather, it's the major muscle responsible for supination: turning your palm upwards. So if it hurts your buddy to turn a screwdriver, that's suggestive of a distal biceps tear. People still have a surprising amount of strength to flexing/curling the elbow, even after a biceps tear. Most people seem to want to get the tendon repaired.

There's a bit of a difference (academically, at least) between a complete tear and a partial tear. You might or might not be able to feel the biceps tendon in that antecubital fossa, even if it's torn. Usually an MRI is done to confirm the diagnosis.

Surgery is best done within the first 2 or 3 weeks. It gets technically more difficult if you wait longer than that. The muscle may cause the tendon to retract, and if the muscle gets "used" to being in a shortened state, it might be difficult to stretch it back out to length at time of (delayed) surgery. That might necessitate the use of a tendon graft to bridge that gap between tendon and bone. (The tendon almost always snaps off at or right next to its insertion into the radius in the forearm.) Use of a tendon graft obviously ups the degree of difficulty of the surgery a little.

There are a couple different ways to do the surgery. But this can only be repaired surgically. At the same time, not everyone has to get it repaired. But most people who tear their distal biceps are middle-aged men. So they'd like to continue with their active lifestyles.

Recovery is a pain. After surgery, the regimen I dictate for patients takes 18 weeks (4 months). 6 weeks for range of motion alone (NO lifting). 6 weeks for gentle strengthening (1-5 lbs). 6 weeks for getting back to full strength.