How to throw the Left Hook properly to prevent Injury

[cocobeware]

So a orthodox left hook left hook is thrown with elbow up so the forearm is parallel to the floor palm facing down and follow through with the elbow until the shoulder covers the chin ?
I used to do it like that as that was how i was taught but i used to always hurt my shoulder blade so i started lowering the elbow and found i got much more power,It was like it brought my bodyweight more into the punch.I also dont follow throught with the elbow as i find i cant get the same snap and again it can cause me pain in my shoulder blade.I usually dont come past half way with it.
So my question is should i go back to the way i was taught or do it the way i find more comfortable.
What is the correct way to throw the left hook?