Its always important to work out with the right gear.
When doing olympic lifting or leg workouts, try using flat soled shoes or even bare feet as it will help you lift heavier and improve your technique. Wearing the right shoes also takes all the pressure off your vunrable ankle joints by speading out the force of the weight across your whole foot rather than on specific points
Take a look at www.dynamic-eleiko.com/products/shoesFR.html for some examples of some hight quality olympic lifiting shoes.
They are worth it.