Thoughtful article. I've had similar feelings about myself and whether or not I'm disabled. My left arm is crooked from two childhood injuries and doesn't turn over more than about 30%, it's called a Madelung deformity[1], it showed itself after my second injury when my arm was healing from a fracture when I was 10 years old.
Most of the time, it's pretty invisible for me and everyone else, but there are things in day-to-day life that are a chore if I think about it, such as cutting food with a knife, exercising, or even trying to hold something at a certain angle with my hand can be uncomfortable. It's kind of silly, but I also can't play guitar standing up, as the angle of turning my wrist over is too uncomfortable to stay in position on the fretboard. Sitting down is similar, but I can play longer as I can hold my elbow closer to my body.
Most of the time, it's pretty invisible for me and everyone else, but there are things in day-to-day life that are a chore if I think about it, such as cutting food with a knife, exercising, or even trying to hold something at a certain angle with my hand can be uncomfortable. It's kind of silly, but I also can't play guitar standing up, as the angle of turning my wrist over is too uncomfortable to stay in position on the fretboard. Sitting down is similar, but I can play longer as I can hold my elbow closer to my body.
[1]https://radiopaedia.org/articles/madelung-deformity?lang=us