I'm not sure how much more energy walking with crutches actually uses. With simple walking you'd get about 23 grams of fat per day (39kJ/g and assumed 220kcal for 2 miles of walking).
Let's say you walk 5/7 days a week and maybe 1 mile on the weekend. That gives us 11 miles per week, 121 over the course of 11 weeks. Let's assume you've lost 10 pounds of fat, 4 pounds of muscles, water etc.
10 pounds are ca 4'540g meaning you used about 177'000kJ. That's 1463kJ per mile or 350kcals.
Huh, more than I'd have expected. Although I've probably overestimated the amount of fat you've lost. Anyways, congrats on the weight loss!
Thanks. Doc said crutches burn about 40% more than just walking, and by the end of the third week as I was developing the upper body strength to carry my fat ass around, I got to where I could move pretty fast on the sticks, quite a bit faster than my normal walking pace. I don't think I lost much, if any, muscle mass overall, what I lost in the one leg, I made up for in the other and arms/shoulders.
It was weight I could well afford to lose. =)