For some time I've been dealing with a recurring feeling of pain and weakness in my lower biceps. The pain is set off only by very, very specific activities — chiefly rope climbing, tug-of-war, and wrestling. I lift weights frequently, but that has never set it off; I can do set after set of pull-ups with no problem, but the second I start climbing a rope the pain appears. (It would seem there's something specific about intense isometric pulling —especially overhead pulling — that sets it off.)
The pain is localized in the lower 2 in. of the biceps and can present equally in either or both arms. It's a dull pain and can be very intense, ranging from 1 to 8 on a 1-10 scale. It is accompanied by a strange feeling of weakness or deadness, which can be so debilitating that at pain levels of 5 and up I can hardly lift my arms.
The pain typically takes 2-10 hours to go away, depending on intensity. Doing more of the offending exercise will reliably increase the intensity of the pain, but otherwise the pain stays constant whether I use my arms or let them just hang there resting.
I can go for months or years without the problem occurring at all, but one I've "tweaked" my biceps in this way they are extremely prone to re-injury over the following days and weeks. (E.g. if I tweak my arms climbing a rope one day, I can set it off again the next day by something as easy as tightening a backpack strap or carrying a shopping bag. But again, lifting weights in the gym with good form will have no effect.) It takes 2-4 weeks to go away entirely.
Ice does not help, nor does massaging the biceps.
The only convincing theory I've heard so far is that it could somehow be related to my rhomboids. I've strained or pulled my rhomboids several times in the past and they're usually pretty tight. I have indeed noticed a correlation between the pain and increased tightness in my shoulders, and I think massaging my shoulders in that area sometimes eases the pain slightly (though I have yet to try getting a professional massage to treat it).
What's going on here? Am I somehow tensing up my shoulders when I climb ropes or wrestle, and somehow my jacked-up rhomboids are referring the pain to my biceps?
I'm in the military and will soon be undertaking a challenging training school with lots of rope-climbing, so this is far more than just a recreational concern. Any advice would be appreciated!
(Note: I'm posting this on my girlfriend's yahoo account because I don't have one; sorry for any confusion!)