Analyzing facial deformation using mediapipe's facial landmark model

Question

I'm doing a study trying to analyze facial deformation energy after receiving a punch for a study.

The problem is, that I'm finding it hard to measure it accurately. The simplest thing is to measure how much all 468 points move, but the issue is that the head also moves after receiving a strike, and all I want to study is how much the face itself changes during a strike.

Does anyone have any creative ways to do this? How do we study the facial landmarks changing while accounting for the head moving?

I'm not sure how to even approach this problem.

I'm using retroactive videos of past UFC fights. I have attached one data source to this:

https://streamable.com/j3a48w