The forearm lies in supination, with its posterior surface next to the plate.
The movements allowed at these three articulations are called pronation and supination of the radius.
Those defending the lower right-hand quarter are “octave” (eighth; in supination) and “seconde” (second; in pronation).
The elbow is flexed at a right angle, and the forearm supported in a sling midway between pronation and supination.
All movements are painful, but especially movements in the direction of supination.
If the ligaments fail to unite, the head of the ulna tends to slip out of place in pronation and supination—recurrent dislocation.
Those defending the upper left-hand quarter are “quarte” (fourth; in supination) and “quinte” (fifth; in pronation).
When the displaced head of the bone interferes with supination, or with extension, it should be removed.
The radius and ulna are parallel in the most natural position of supination.
In the eccentric position the wrist is in supination; that is, the back of the hand is downward; this is the sign of impotence.