What’s the most “ATG” internal rotation stretch? I haven’t found it necessary for my body. But it’s worth exploring if there is one stretch worth adding. In person we did 90-90 stretch for both external and internal rotation. Gentle, long duration.
Also: what muscle is being stretched? So many athletes who don’t do any mobility work have AMAZING internal rotation from sport adaptation. I.e.: watch Allen Iverson, Kyrie Irving, etc.
I haven’t seen that with any other area and I try not to add things to ATG that aren’t essential. So I’m not saying I’ll add it to the ATG system, but I’m not opposed to exploring it if it can be trained per ATG principles: comfortable, scalable, measurable, has a direct purpose and result when done consistently.