Doing Roca Ball rotations will strengthen the fingers, hand, and forearm. To perform the exercise, hold two one pound balls in one hand with the palm facing up. Starting slowly, rotate the balls in a clockwise or counter clockwise direction. Depending on your strength, you can support your arm or do the exercise unsupported. If your arm is unsupported, the exercise will work the forearms and biceps more.

The exercise can be done while sitting or standing. When sitting or standing, it may be easier to do with the arm bent closer to a 90 degree angle than if stretched out. When sitting you can also rest the forearm on the arm of a chair or couch, or on your leg.

As you improve, you should be able to increase the rotation speed and the length of time. It is best to start off slow.