Arm swinging as shoulder joint prep

Also teaches how to generate power from the middle/center to the extremities.

 

Some examples:

 

 

https://www.youtube.com/watch?v=9ODJwQ12AqU&feature=youtu.be&t=2m18s

 

Thoughts?

Unfortunately I don't understand what he says. Amongst guys in my climbing gym, arm swings usually matched a description I read somewhere, "some warm up exercises look more dangerous than the activity afterwards".

Any video examples of what they do?