Chester
You need to understand that this is just a form and no more, it at best is a précis of the legal criteria against which you will be assessed.
The legal requirement is that you are able to place at least one biological foot on the ground so you should indicate that you cannot stand and move (walk) more than 1m and explain why this is the case.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems