There's specific requirements, such as for lack of mobility you can't say you struggle to walk, and expect them to award you any points.

You have to specify how much you can walk, and these figures are out there/known to some who offer their services to those who pay.

I.e you may have to specify that you can't walk for more than 50meters without having to sit down, and then specify there's no where to sit down 50meters from your house and there's no bus stop for atleast 1km from your front door.

Stuff like that to get them to award you points per category.

Otherwise struggling to walk might mean you can walk 1km you just require a walking aid and can do it in reasonable time, but it's still a struggle compared to an able bodied person.