The will check the circulation and pulse, also use a very fine pin/needle to check how well or not you can feel sensation in different parts of your foot, sometimes the use a tuning fork on the foot to see what of vibration you feel ( this is wired indeed, as every time I'v had this one done, I can feel the vibration up through the bone as well right into my lower leg, which I am told is a very good sign indeed) then they will give them a look over between toes etc, to see if you might have any problems athlete foot, hard skin etc..
You will be told straight away if they find anything and what if anything needs to be done about it...
Good luck, you should be ok, unless you've got ticklish feet :lol: