I’m trying to get more mobility for hip-shoulder seperation. what muscles/areas do I need to work on? Lumbar spine?
The lumbar spine is designed for flexion/extension - not rotation - so training the lumbar spine to improve separation could get you injured.
The upper (thoracic) spine is designed for rotation. But I suggest your initial focus should be on mechanics and timing to make sure you’re not doing anything to cause early shoulder rotation.
I definitely have early shoulder rotation.
I’ll work on the mechanical aspect first and then worry about the mobility one. I had thought it would be good working on both at once.