The embrace completes the arch of connection and is part of the stabilization chain. To keep the embrace taut, light, and agile in every position, and throughout pro and contra movements, we maintain:
 external rotation of the shoulders
 gentle contraction of the triceps muscles.
The main job of the triceps muscle is extending the elbow joint. But like any muscle, we can also contract isometrically, which means contracting without moving the joint. The isometric contraction stabilizes the joint, so that it won’t easily flex or extend in response to small changes in force by the partner, such as the communication about intention/projection.
The isometric contraction keeps the muscle pair (biceps+triceps) on alert, ready to respond to movements with larger forces.
Triceps contraction causes the embrace to feel light, or “filled with air”. Many dancers instead contract the biceps, which feels heavy and hungry.