...but that way of jumping back an raising the feet is typical of people who have been exposed to being students of southern-China-origin Taiji people. ...
This wierd hoppy feet-lift is something I've noticed over the years on Taiji-related videos, it's a movement not normally necessary for regaining balance after being shoved backwards ... I just concluded it was a learned response which is encouraged by their authority figures and peers. Is that the whole story?