Broly crew, I've had posture & lower back pain for as long as I can remember. It's becoming a problem now that I'm working out during my abs routine. When I'm doing heels to the heavens (lie on back, straight legs up, using abs to raise your ass off the ground) I get this sharp pain in my lower back which makes it hard to continue. Any ideas how to alleviate this pain? Is there just a tight muscle back there I need to stretch out and work?