This video is a response to a question from Barrett regarding the safety and utility of the "sleeper stretch" for improving shoulder internal rotation. He reported he has heard mixed things from other movement professionals regarding whether it is safe or useful to perform. He also reported that when he does attempt the exercise he experiences "an incredible amount of impingement in the front part of the shoulder."
My stance with this movement, as it is for most movements, is that it is neither inherently safe or unsafe. Safety and usefulness will be dependent on the ability to maintain breath and postural control, as well as to use the symptom as a marker of readiness to move farther into the position.
I describe the ability to produce a "pump handle" expansion into the chest of the side being mobilized as an important marker of breath control. While the ability to internally rotate the humerus without an anterior translation as a marker of postural control.
I also demonstrate the addition of an isometric contraction to the posteriorly-oriented external rotators to move the compression from anterior to posterior when an anterior impingement is present.
Please comment with questions. Happy to discuss further.