I don't have foot drop [yet]. But I should have...early on [I have a very agressive Peripheral Neuropathy] I realized early on that physical therapy could/might/should help me regain some strength and flexibility and it did. After my first 'round' of PT I also realized that I should ASK docs for instructions to therapists that could give me 'tasks' that I could do at home. It helped immensely. Finding a good therapist is a matter of trial, error, communication and lots of luck! The latter I truly hope you have.
As for your muscles not flexing? Well, once locked it will take a lot of massage and trial and error to find the things that work. I am recovering from a major leg surgery rite now and find my ankle on that side wanting to 'lock up'! Just don't let it happen, some hurting will occur during PT but it shouldn't be blinding-if you get my drift.
Silly tho this seems? IF you can wiggle your toes? Keep wiggleing them! With a vengeance...IF you are still, and listen to your body, you can feel it all the way up past your knee. It is surprising how important your toes are to the overall aspects of what are, essentially, learning to walk all over again!
Don't overdo new things too much too fast tho...I have found that you will have to learn your own pace in doing even the simplist things. We are in an odd situation where 'no pain/no gain' does NOT apply. I admit that I have been lucky with therapists who HAVE been able to gently coax muscles into stretching and doing more than I thought possible....other therapists can be seemingly cruel and stay far away from them IF you can. In your case sounds like coaxing is a whole lot better than forcing.
Learn as much as you can about PT and if the one you have is truly trained and 'certified/licensed' and go from there. Keep us up to date, please.
Hugs and hope - j