Front leg is out of wack. She plants it in the dirt with toes facing the catcher, puts her weight on it, and then torques her body against it forcing it to rotate while planted. The knee joint isn't made for that. That rotation should happen in the hip prior to the foot plant. She pushes hard against that front leg creating a rearward offset thrust against her pelvis and that helps her take slack out of her core and generate a more powerful turn.
The knee isn't oriented in the plane of that thrust and so there's a torque applied to the knee joint.
Address the issue by externally rotating / opening the front leg before foot plant.
Bobby,
When a player stays closed the way my kid does, she is using the rotation of her body to power her swing. It’s the way she generates force in a small window. Rotational velocity through rotational acceleration and deceleration.
I know you and a few others think you open up to rotate faster. But it’s actually the opposite. I will not get into it right now, but it will eventually be common knowledge and you can learn it.
Side note: she was hitting a change up, so there was a big adjustment there. But I know you just want to nit-pick anything you can for obvious reasons. Look at the videos of my kid I posted. The front foot opens. But anyway...
Go look at some HOFers. You will see the same thing. Some will roll over the ankle and stay closed. Some will open up the front foot at backside release like my kid. Some will stride open and the back leg will not rotate as much. They are channeling the force in ‘their’ proper direction(s). The ones they ‘use’.
It has something to do with the force vectors players use to generate speed. Every player is a bit different. That’s why hitting is tough to understand and teach. In a perfect scenario, you could teach vertical, horizontal and torque force to every player. But they all don’t move the same so you have to find out what their body wants to do and help them enhance that. Your ‘cookie cutter’ analysis will help some and hurt others. You need to understand what you are dealing with.
But so far you say ‘hold onto the bat and rotate’ ‘drop and drag’ the bat to contact. Either you haven’t seen good pitching or haven’t encountered good competition. Or maybe your descriptions just lack. I’ll give you the benefit of the doubt.
Maybe post a video of some drills you like or a student you’re proud of. I’m not demanding or calling you out. I’m just tired of wasting time countering some of the weak points you keep making.