Stirring is a mechanic that many people default to when trying to lead that uses musculature in an isolated part of the body to attempt to initiate larger motions in the follower. This creates proprioceptive feedback and motions do not inherently follow the ergonomics of incorporation. This is most often in the elements of timing, and flexibility but also active dimensions as proprioceptive issues make dimensional awareness difficult.
The classic version is using the hand to move the back in order to lead shaping like body rolls or other forms of back shaping.
This may seem like the most direct way to initiate such however it can lead to miscommunication, force leading and connection/support in vulnerable spinal positions.
We address Stirring like all forms of arm leading. By creating the energy and motion of the body near the initiators center if not lower. That way the imitator creates the idea by running the mechanic through their own body. This makes the mechanic communicated something that works with a human body and thus barring significant capability differences works for both bodies. It also allows the motion to flow showing the shape of the move allowing the incorporator some understanding before incorporating the energy into their body. This also provides a solid source for the energy that then can be redirected avoiding the issues of parallel motion leads and change of frame leads at the same time.
With skill, the energy generated and transmitted through the larger body motion can be accentuated in the follow. To create much of the aesthetic that people are going for while stirring without the dubious and dangerous mechanics.