The triceps brachii is stretched with full flexion of the forearm at the elbow joint and full abduction of the arm at the shoulder joint.
Note: The medial and lateral heads of the triceps brachii do not cross the shoulder joint, therefore, to preferentially move the stretch to them, the shoulder joint can be placed in anatomic position.

The triceps brachii is stretched with full flexion of the forearm at the elbow joint and full abduction of the arm at the shoulder joint.