Coaches Back Uprises Froggy Legs Help!

[CoachVictoria84]

Hi! I have a gymnast who is 10 years old, progressing very quickly! Progression is always fantastic however her back uprise form is horrendous. When she keeps her legs straight she doesn’t make the back uprise, and I’m not sure how to fix this. I’m considering teaching her to straddle back; but I’m not sure how to teach this. Any advice is very very appreciated!!