Hey Volleynerd. At 4:10, you talk about how most players would stop at that shoulder position and proceed to swing instead of going as far back as Tj does, do you have any tips or recommendations as to how I could achieve this level of flexibility and loadup? I'm currently struggling with this very issue.
First - Acquiring range of motion is very difficult. It's a slow, often painful process. Generally, the underlying problem isn't "being tight" or having "short" muscles, it's strength. And not passive, isolation strength, strength in motion. TJ demonstrates this sort of strength in his swing. I would recommend looking up FRC (Functional Range Conditioning). That method tends to be a good starting point for most people. While working on your range, also practice quality arm swing mechanics. The stronger and more coordinated you are in your swing, the better any training you do will transfer to it. Hope this helps!