I would like to buy my father a fitbit but not sure if there is any chance at accuracy. He broke his hip recently and is using a walker, probably will for many months to come and perhaps forever. He would like a fitbit and has been borrowing my mother's (she has a One) with mixed results. One day he had about 1,200 steps which mom reckons was faily accurate. Next couple days showed about 100 steps. He has been clipping it on his hip but not really lifting his leg, more shuffling than anything. I have asked him to move the Fitbit to shirt pocket and other hip. Anyone else been in this situation or know someone who is? Is there a Fitbit more sensitive to movement than the others? I am assuming choice is One or Zip since his wrist is always immobile holding on to walker. I am even thinking of hooking it on walker itself but he does take some steps without it throughout the day and don't want to complicate things by having to move Fitbit repeatedly. Thoughts?