Pfft! What part isn't in pain! My right arm and shoulder are so sore right now that I can barely move them. The pain is bad, but I'm managing not to scream.
There are many causes, from years of wear and tear, to plain old stress. Eventually, the worst pain will shift to another location. The rest is here to stay.
Feet, mostly my right foot has been giving me pain for some time now. I think its a nerve thing and I gotta see about getting treatment for it one of these times pretty soon.