Both Matt and Art nailed it... I"m not a good-enough Photoshopper to take your pic and draw a line on it, but if I did you'd see that you're leaning back and your upper torso is not centered over your hips; sometimes that's a dl problem, sometimes it's bad habit of just unkowingly leaning back. The front shoulder riding up on you was actually the first thing I noticed, followed by the grip.