Improve Your Backswing by Improving Your Posture

Sean Cochran of PGAtour.com has an article that emphasizes the importance of posture in improving your backswing. Here's the reason it is important:
"In order to maintain a fixed spine angle during this phase, the golfer must have certain levels of postural strength. Postural strength allows the golfer to correctly sequence the muscular contraction required of the swing, maintain a fixed spine angle, and generate power."
The full article is here.
If you like golf specific exercises and want to improve your golf fitness I can recommend you the Ultimate Golf Fitness Guide.