Shoe inserts?

I have seen several people mention inserts for their shoes that keep their heel up. Can someone provide some more info on them. As I mentioned, I’m about to get my cast off and don’t know if my foot will go 90 degrees.
Thanks,
Brad

3 days until the cast comes off!! Someone give me a hacksaw!

3 more days. I know I can make it. I have been hobbling around for two weeks without crutches. (Against doctor’s orders.) Foot will swell a little a night. Can’t wait for the boot and a nice warm shower!!