Nerve Strain or Muscle Pull?

[XxgulliverxX]

This may or may not be caused by a sudden hard pull up workout wherein I came to a complete dead hang, allowing for as much of a stretch as possible (potentially pulling the latissimus dorsi apart?).

At any rate...

I have an intermittent pain, off and on all day long, that can last for as little three seconds or three-plus hours--usually closer to the latter.  It occurs around, literally, my right shoulder blade, my right trapezius, the right side of my neck, the outside portion of my right arm and my right tricep.  The pain is not always in the same area but it is always in one or more of the areas I mentioned.  It can be a dull ache or, if I stretch or strain in a particular direction, a sharper but not acute pain.

I was torn on whether it was a muscle or nerve problem because it's a more unnatural, nerve-feeling kind of pain, but the reason I had considered a muscle problem is because my strength in my right arm has dropped precipitously: lifting my arm straight out is as difficult as lifting a 50 pound dumb bell, I can't easily do a push-up or a dip a shoulder press exercise, let alone pull-ups.  There is no power; it's completely weak and instead of using any lat-muscle strength it seems that when I attempt things with my right arm it only uses back and shoulder muscles.  Even reaching for the radio knob in the car is a challenge.

I have been taking it easy for awhile--going on 3 weeks now--but it has not gotten any better at all.  It is pretty frustrating because I like to keep in shape, running or lifting weights every day, but with the weather here right now lifting is the only thing I can do and now because of the injury I can't do anything.  I feel like I am distinegrating because I can't really exercise.  I also drive a tank in the military where we are expected to lift and carry heavy things and perform a lot of functions requiring the use of those muscles (e.g., dip-like function getting in the hatch), so I need to get better as soon as possible.