Difficulties

OK, so I knew about one difficulty before I started on MFP: I've got no working scales and have to wait to see the nutritionist to get weighed.... usually some weeks between appointments. The other difficulty involves the question of burning calories: my disability condition is such that I'm in constant pain (good for consuming calories), walking increases pain and requires considerable effort, and stairs are on a whole different order of energy expenditure! I've no idea, then, as to just how many calories I burn on an average day.... without even thinking about exercises....