HOW: Get set up sitting upright with a surface near you to support your elbow and forearm. With your elbow flexed to 90˚, position your forearm and wrist in a neutral position with your thumb facing up, and have your hand unsupported at the edge of the surface. While maintaining elbow position and holding a long weighted object such as a bat, perform pronation and supination. See the video for other tips and instructions.
FEEL: You should feel the muscles on top of your forearm working as well as other muscles in your forearm and hand to help with gripping the object. You may feel tension on the outside of your elbow as well.
COMPENSATION: Perform slowly, do not lose elbow position, do not lift your arm off the surface. Try to keep your forearm still on the supporting surface.