Hopefully this ludicrously-lame GIF makes more clear the action of the Arms in our TaiJi Circles…

The Arm action has been reduced to it’s most basic form:
“In with the Elbow…Out with the Hand”
The two components not as clearly articulated here are the “Turn the Waist”-phase of the Circles, as well as the “Recovery”-phase.
This serves as a good reminder that once the arms have completed their task, they no longer need to DO anything (except for Listening or holding space, as the case may be), and the rest of the Body continues to direct and/or utilize the Energy.