Forearm Supinator Stretch

Arm, Wrist, and Hand Stretches:

Method:
Stand with the back toward the inside of the doorframe. While keeping the arm straight, hyperextend the right arm above the midpoint between the hip and shoulder. Grasp the doorframe with the right hand with the thumb pointing up. Internally rotate the arm (roll the biceps down).

Affected Body Part:
Most-stretched muscles: Right biceps brachii, right supinator.
Lesser-stretched muscles: Right brachialis, right brachioradialis, right infraspinatus, right teres minor.

You can also do this exercise with a firmly planted vertical pole. To maximize the stretch, keep the elbow straight. After rolling the biceps downward, you can enhance the stretch by inwardly rotating the back toward the hyperextended arm (see figure).