Your trigger finger is simply the index finger of the top hand of your golf grip. It can be used to help direct the club during your swing or help control the club while putting. It's worth experimenting with the movement and placement of your trigger finger when gripping your driver, irons or putter.
Pressure Point
PGA pro Bobby Clampett notes the trigger finger is especially important, though often overlooked, when it comes to loading the club on the backswing and lagging it on the downswing. You should feel the pressure of the club across your trigger finger when you bring the club back to the height of your backswing, and then use that finger to help drive the club down toward the ball, leading with the hands and trailing with the clubhead.
Maintain Control
If you separate your trigger finger a little from the rest of your fingers on your top hand, you may find that you have a greater sense of control of your grip and swing. The separation should help you maintain a steady grip pressure with both hands and help with club rotation in the hands during the swing.
Putting Control
Another common use of the trigger finger is greater control while putting. When putting, instead of separating your trigger finger from the others, try extending your trigger finger down the side of the grip so the tip touches the fingernail of the opposite index finger nail. This helps keeps the hands interlocked. It's a popular grip on the PGA Tour and you may find that it gives your putting stroke that extra sense of control.
Precautions
If your trigger finger starts to give your golf game trouble, get it checked out soon. You may have rheumatoid arthritis or some other malady. However, a coritsone shot or even prolotherapy may be all that's needed to keep a troublesome finger from ruining your golf game. Prolotherapy is the injection of a sugar water fluid into an area that has experienced injury to tendons or ligaments. The joint often comes back stronger than before.
