Major Muscles and Actions Involved

The supinator and biceps brachii are involved in supination, whereas the pronator quadratus and the pronator teres are involved in pronation. In supination the palm of the hand is turned upward while the elbow is kept bent, preferably at a 90-degree angle. In pronation the palm of the hand is turned downward while the elbow is kept bent at approximately a 90-degree angle.

Muscles in Action

Sports Uses

Of the two movements, pronation is more important in most sports actions. However, to keep the muscles in balance, the supinators must also be adequately developed. Pronation is used in almost all hitting and throwing wrist and hand actions, as for example, in baseball pitching, football throwing, baseball and softball batting, racquet sports forehands and overheads, and in the golf swing.

Important Facts to Know

1. Supination-pronation is often done with a dumbbell. However, it is not very effective when done this way because the resistance lever arm is too short. In essence, the closer the resistance to the hand, the easier it is to turn your hand and the less development that can occur. However, when you are using the Strength Bar, you can adjust the length of the lever by holding the weighted end closer or farther from your hand.
2. To isolate the supinators and pronators, you must maintain your elbow at a 90-degree angle when you execute supination and pronation. In this the forearm should remain level in a stable position at all times. This means you can also do it in other positions but only if you maintain a level forearm. Because of the difficulty in doing this, it is usually not recommended.