In Vancouver June 2014 workshop, Master Chen explained a common error when students doing circle. During elbow in the elbow, shoulder, front kua have to come close together. During hand out hand and rear kua have to move apart.
The torso/leg has to facilitate a lever during a circle, it doesn’t reverse in the middle of the move. Common error is for the kuas to reverse then this is doing a circle only on the same side of the body.