Each finger has a significant contribution to overall grip strength. It is obvious that the use of all 5 fingers (the 'power grip') enables the greatest hand holding ability. Grip strength without the thumb (the 'hook grip') is the second greatest way to provide hand strength. The largest contributor of the hand to developing power is the middle finger, next the combination of ring and little finger working together. When gripping without all digits hand strength becomes lower. Knowing that each finger's power changes how you can hold on to, control or manipulate something, it is understandable that it is important to target each finger systematically during training. The Pendulum Grip Cart http://www.rogersathletic.com/pendulum-grip-cart/ vigorously addresses each digit, as well as, the various ways the hand interacts with objects.
The Pendulum Grip Cart