A cupped or for the medical types a wrist that is in “dorsiflexion” has the potential to ruin even the best of golf swings you make out on the golf course. What it means to be cupped during your backswing is your left wrist bends so that the back of your left hand and the top of your left forearm create an angle like Photo 1 below.
 

The more the left wrist cups, the more trouble we will find ourselves in during the remainder of the swing. Typically golfers who cup the left wrist the most will bend and fold their lead arm the most, separate their arms from their chest and body, and finally open the face of the club to the path they are swinging on (Photo 2), and swing the most over the top. That’s a lot of problems for just having a cupped left wrist, and they’ll always result in a shot that slices, fades, or travels high and to the right, and creating a huge lack of distance. If this sounds like something you do, let’s fix your problem with this simple drill involving a book or, in my case, a tablet.

BOOK DRILL

The book drill is a very simple drill that can be done almost anywhere you have a hardcover book, clipboard, etc. Begin by taking the book and place it in your hands, using your typical golf grip with book between your hands, between your forearms (Photo 3). Next, take a few slow backswings and take note of what forearm the book touches as you make your backswing. If the book touches your right forearm, take a look at your left wrist, you will notice a break or angle and not a flat of bowed left wrist. Repeat the process again and this time make sure the book is touching your left forearm (Photos 4 and 5). Look back at your left wrist and notice a FLAT wrist! Make a few more practice swings with the book until you master the ability to let the book touch your left forearm.