When you watch the U.S. Open this weekend, one thing you'll notice about most of the golf swings is that there is very little extraneous movement. Top-level golfers know they can't afford to hit the ball anywhere but in the center of the clubface, and that requires a very stable lower body.
Amateurs have far less control of their lower bodies and often sway too far off the ball in their backswings and/or slide too far toward the target in their downswings. This makes it very difficult to consistently hit the ball on the sweet spot of the club. It's like trying to make a free throw without stopping first.
The culprit for this sway/slide is often weak hip adductor muscles. This group of muscles that runs along the inside of each of your thighs is greatly responsible for internal hip rotation. And without the ability to rotate your hips toward each other, you won't have the strength to stop your body from moving in the direction the club is moving. Have you ever heard an instructor say "swing within yourself"? What he or she means is that you can't let the momentum of your swing throw you off balance or you'll struggle with solid contact.
The hip adductors are often completely ignored when training, says Ben Shear, one of the top fitness consultants on the PGA Tour. Shear (@Ben_Shear) trains Luke Donald, Jason Day and Webb Simpson, among others. When amateurs come to his gym, Golfer's Edge in Scotch Plains, N.J., he often finds these muscles are not only too weak, but too tight to function properly.
It's easy to correct these issues, Shear says, and he uses a two-pronged attack of softening the muscle tissue to make it more mobile and then strengthening the muscle group to make the region more stable. Click on the video below to see a demonstration of how you can train your hip adductors so you can swing with more stability.