The first thing I look at when I am teaching is my student’s feet. The feet are the foundation of the swing. They are the first link in the chain that must conduct a series of muscular actions resulting in the loading and unloading of the body during the swing.
The right foot (for right handed golfers) in particular, has a very important function in establishing the proper torque and stability at the top of the backswing. The right foot has to feel like it is getting “screwed into the ground” during the backswing in order for the proper kinematic sequence to take place in the golf swing.
One of the keys to right foot positioning is the shape of the arch of the foot – I’m talking about the long arch along the inside of the foot.
If the foot is pointing at right angles to the target line, the foot is in its biomechanical strongest position, ready to provide a great foundation for the swing.
However, if you flare your right foot out to the right, the arch lengthens and the inner edge of the foot collapses toward the ground. This is a biomechanical weak position – the arch (and therefore the foot) is no longer providing a great foundation.
You can prove this to yourself with the “posting test.” Place your feet shoulder-width apart with both feet pointing straight ahead. Now transfer weight to your right leg like you would in the golf swing. You can feel how solid and strong your right leg has become. Next, flare your feet out to the sides at a 25-degree angle. Again apply pressure to your right leg. With your feet flared out, your leg feels loose and much weaker, making it so much harder to connect to the ground properly on the follow through.
When you understand the importance of your feet in the golf swing you start to understand how the feet make the rest of the body react to what they are doing. If your foot is flared out, the hip joint is externally rotated, putting the hip in a weak position that makes it harder to torque and stabilize.
If you want more power and balance, try squaring up your feet.