Often, if its to do with the foot not being supported properly, or the ankle tipping, the back can do much more work if they move their hand down so that they are right on the ankle joint, and can squeeze it to stop it tipping...
Ive seen many backs work really hard and pull up really hard, but because they are just a little too high up on their flyers ankle it isnt doing any help. Alsoo, we did a little stunt group spirit challenge, where for each of the main stunt groups (the one legged sequence) we all chose a colour and each week we work to earn points, for things like hitting, or attitude or if our coach see's some really good progression ect...and then at the end of each term/at a big comp they scores get added up and whoever wins gets a little prize :)
It was so much fun, and we all got really into it, like wearing our colour to practice, we all made bows in that colour, had little mini cheers for our colour, all sorts :) it really increased team spirit and made us work harder to get points
Good Luck!