The supine hip-rotation stretch is a safe and effective exercise to help you reduce hip-rotation tightness and, therefore, improve your ability to make a full turn around your hips during a full golf swing.
Perform this releasing exercise as follows:
Lie on your back close to a wall. Place both feet on the wall so that your hips and knees are bent about 90 degrees.
Cross your right foot over your left knee and rest both hands on your right knee.
Gently apply pressure to your right knee with your hands in a direction down and away from your right shoulder until you feel a light, comfortable stretch in the outer portion of your right hip and/or groin.
Hold this stretch for three to five minutes or until you feel a complete release of the original stretch in your right hip.
After the stretch is complete, slowly release the pressure on your right knee and repeat the stretch on your left hip.
Practice this releasing exercise at least once a day for two to three weeks or until you can stretch equally well in both hips. If you found one hip to be tighter than the other during the seated hip-rotation stretch, then initially spend more time stretching the tighter hip. Your ultimate goal is balanced rotation for both hips. Only by achieving complete and balanced hip-rotation flexibility can you accomplish a full backswing and follow-through with each and every swing.
After you're balanced, you can advance this stretch simply by moving your body closer to the wall at the start. This allows your hips and knees to bend at an angle greater than 90 degrees, for a greater degree of stretch in your hips.