Flexibility
/Let me be the first to admit that if you are already in pain, stretching may be the simplest and most straightforward way to temporarily get rid of it. Fair enough. But until you change the regular activity (or inactivity) which is causing the pain, the pain will keep returning.
Dance is generally a good way to develop flexibility. Unfortunately the standards of ballet and most modern dance are based on teenage bodies, which are far more pliant than adult bodies. Thus injuries are too common. But there are many different types of dance.
I know most martial artists are afraid of dance, but incidentally I was at a serious Kick-boxing gym last night where fighters were jumping rope and doing endurance training. I'm willing to bet that any professional ballet dancer can beat these fighters in an endurance match.
I suspect that most people will not understand what I am saying because they don't have the experience. Let me put it another way. If it hurts, it is wrong. If it disconnects the limbs from the movement of the torso, it is wrong.
If Elvis were alive today he would have put it this way: If your "downward dog" can't chase rabbits (or at least scamper around the kitchen), he ain't no friend of mine.
I know that was some tough talk, but if you still love stretching (think pain), contortion is a great option! San Francisco now has a world class contortion training program, The Circus Center. Make sure you scroll down to the middle of the Adult classes part of the schedule where it says Advanced Contortion and Mongolian Contortion. This is the real deal!
(Also, yesterday I attended a fabulous show at The Circus Center's Clown Conservatory, for those of you into the high art of clowning!)