Add all thumbnail videos with descriptions on the side (3 sentences long each). 
Have each video linked to the next page on the same webpage. Add comments to the bottom of the videos. 

Videos: Sections
Wunda chair beginner, mini video - click and move to just the big video page then under those titles write spine stretch : Little written description  (1 M spring, what its not good for and who shouldnt do it, what muscles it works, etc.

Wunda chair intermediate
Wunda chair advanced