Nike have released a new trainer that zips open at the back which makes putting shoes on top of AFOs much easier.  There are a few designs and they are reasonably priced.

https://store.nike.com/gb/en_gb/pw/flyease-shoes/pjpZoi3?nst=0&cp=euns_kw_bra!uk!goo!styles!c!b!%2Bflyease!