Sounds like spasticity to me too... I have had pains that small in my arms and legs - I always figured it was a little muscle cramping up. I have a specific muscle in my right arm that cramps constantly, and it's been doing that for four months - so I definitely think you could have spasticity in a muscle for a long time.

On the other hand, my left calf was really sore for weeks and wouldn't quit being sore... until this Saturday, when I woke up and it didn't hurt at all! Yay! I guess that nerve healed up.