Hopping stance in Tae Kwan Doe

Muriel does well in class. She is so shy though. It's like she doesn't want to be there BUT once home wants to show us what she has learned to do (then shows off how well she can do it). She can do this.

Now, watch Lillian. That right leg of hers is short which results in her inching her way forward while jumping. She cannot stay in one place. The guy helping her is always getting her to back on her spot. She really enjoys it and tries so hard to get it right.