I just had a 13 year old golf player come in from one of the local golf academies. She has been having large amounts of pain in her lower left back. Upon examination she pulled her left sacro-illiac joint out of perfect alignment. I put it back in place and told her if she wanted to keep it in place she would have to quit stretching on concrete before she golfed. Outside of that my advice was come in when it hurts and when is doesn’t don’t bother. This was a case where improper stretching was causing the pain.