I have back and hip issues, but not from training.  I was a year from my black belt test in 1996 when I was in a rear end collision.  I was hit hard enough to hit the car in front of me.

I went to the chiropractor, for about 6 weeks until I ran out of money from the insurance settlement.  My flexibility was severely affected.

I earned my black belt a year later, but certain things made it so painful.  I hate taking medication, fear if I take it, it'll lose its effect when I really need it.

I continued to train, after black belt, but not as much as I once did.  About 8 years later I began to train once again, full time, and then a year after that I began even more, as I teach and train.

I just recently got medical insurance though work, and have been seeing a Chiropractor again for about a month.

Though my hip isn't wedged in a weird position, I do still have damage.  Some of it from the accident, and some of it I was born with, and really didnt' know I had the problems until the injury.

My leg is 3/4" lower than my left.  This makes my right hip 3/4 inches lower than my left.  It causes pain when I land heavy on my shorter leg.  It also hurts when I do specific kicks without extra warming up.  The chiropractor is got everything back in line, but now I have to wear a wedge in my right shoe.  I can no longer train barefoot.  I take advil only in rare situations.  I continue to stretch, because it is worse when I don't.

Oh, sorry for the long post. ;)