JXStern, before both of my knee joints were replaced, I'd wrap them with
several ace bandage (the ones with Velcro & start the wrapping away from the
heart) It supports the knee and immobilizes it a bit. Also before each knee
replacement surgery, I had my husband layer 2 applications of capsasian
ointment until my skin burned more than my knee. Not recommended by doctors
to sleep with ace wraps on, except after surgery -- surgery area swells. I
nearly waited too long to get the knees replaced: hairline bone fractures
and bleeding. I used to sweat, hyperventilate and scream in getting up from
sitting.

The thigh muscle pain sounds like a static convulsion, which jams the knee
bones together causing even more pain. She might try putting a bag of frozen
peas on the muscle, and then warm compresses, then the frozen peas again,
repeating. The pain feeds back on itself and the brain can be fooled into
not feeding the pain by making the muscle feel something almost a strong as
the pain. Be careful of frostbite, though.  Jan2 [not Jan]

maybe massage would help loosen up the muscles some so PT could build on it?  
And using heat packs on it at home?

Are they doing anything so that walking on that knee doesn't further
aggravate the thigh muscle in between appointments?  bracing or I don't know
what else.  PT folks should know what's best in her case.  But I gotta think
the knee situation isn't helping the thigh muscle any.

I had muscle spasms in my back that wouldn't release except using trigger
point therapy, once by Massage therapist, and once using
electro-stimulation.

The massage one was a fairly painful experience, but afterward I was
blissfully like jello. The electro-stim wasn't as deeply relaxing and is
kind of creepy feeling, but definitely helped.

I have just ordered an exercise foam roller (6 inch round, not half tube, by
36 inches) on the advice of a cousin who is a professor in exercise
physiology. You can use them at home for trigger point therapy. That entails
laying on your tummy on the floor with the tube under the quad muscle. You
start just above the knee (elbows propping you up). When the pain from the
pressure eases up about half-way, you roll slightly to get about an inch
more of the quad. Continue slowly up the quad until you reach the hip.

He actually told me to do it on all four sides of each leg, if I could stand
it, to equalize the muscles all around the leg. When only one is tighter
than the other, it reeks havoc with the joints.

He also warned me it would be very painful each time I did it until the
muscle stopped spasming. And that it could take months to get to that point.
But he also promised that in the long run, it would be worth it.

His wife used this technique to help her as she prepared for the San
Francisco Marathon while rehabbing a strained knee. She ran her best time
ever (about 3:45) with no exacerbation of the knee. In fact, while other
runners were hobbling for days after, she said she only had about 36 hours
of discomfort after the race.

Yeah, I know - they are athletes, we are gimps. Not sure what your mom can
manage, given health, strength and age.But I'm trying it because I already
know what the trigger point pain feels like, and the muscle spasm is fairly
painful in itself and affecting both knee and hip. I'm relatively young, and
at least there is some hope of less pain long term.

Good luck!

Adelle