My massage therapy school also started the movement training part of things with the hips and legs. Both feet firmly planted in a lunge (one foot somewhat forward, one somewhat back), shift most of the weight from one foot to the other while keeping the spine upright. As a result the hips glide back and forth while everything above them just comes along for the ride.
Each is appropriate to the intention of the movement. In Rubenfeld the purpose is to reach out from a centered place to just touch and listen. In Massage Therapy the purpose is to facilitate shifting one's body weight into a massage move.