Gym

So, my terrible squat form is trying to come home to roost. I've not injured myself but basically because a congenital hip problem I basically squat like a frog and freak the trainers out. I may have promised not to go higher in weights until my knees stop wobbling. Problem - the weight I am at is low enough that it is not challenging. Therefore I am stuck - unless I can grab one of the gym trainers and go "what's the gym's policy on box squats and what can I use as a box?"