The purpose of frame (deprecated) is to maintain perfect connection. In place of frame, we build an arch of connection. The embrace completes the arch. We use external rotation of the shoulder joints (contracting the rotator cuff muscles) and gentle contraction of the triceps to stabilize the elbow joints while allowing for agility in adjusting to changes of embrace and power flow through the bodies.
Frame is deprecated because it suggests maintenance of a static embrace, when the embrace needs to adjust all the time.