Heyo! Found some videos that I felt explained the shoulder prehab effectively.

This is the facepull --

-- he talks for a while, 5 minute video but he does go in depth to make sure you understand why you're doing it, not just going through he motion.

This is one I use for shoulder warm ups --

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followed by this --

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I mix it up with those last two videos, but I make sure I go through a few movements when preparing for training each day. It's helped a great deal with shoulder pain and mobility!