I was doing martial arts a long time ago and was rather flexible. The last 6 years I only do weights (no stretching). Last 3 years I focus on Squat and DL. I rarely had any problems. On April 2009 though, I started having severe muscle pains in the lower back, due to DL. Like, it would be difficult for me to get off the bed in the morning. Some times it would be difficult to lift a hand. After 1-2 days the pain would go away, but if I did DL, it would come back. Bob Pitatzidis Thessaloniki - Greece