I'm looking for information on what might be the cause of what my wife
is describing as shoulder pain.  She says that she has pain roughly in
the area of her right shoulder, approximately where her bra strap
would run and extends to the back about 4-5 inches, across the top and
then down the front a few inches.  She has evidently had this for 2-3
weeks, in which case the pain has increased over this time in spite of
her attempts to rest the area.  Products like Motrin do not ease the
pain.  The area is very sensitive when rubbed, but she said that a
tapping motion feels good.  Her range of motion does not aggravate nor
negate the pain.

There was no particular trauma that we can trace to the cause.

She's going to go to the doctor this week, but I'd like to know what
might be a probable cause (I understand that a description is not the
best to go on) and/or what might relieve the pain.  I'm concerned that
even though she's trying to rest it, ultimately she may need to
immobilize it to allow the healing process to complete.