After years and years of playing sports, in late 2012 I stood up and my ankle rolled. It was a bad sprain and took about three months to heal. I didn't think anything of it only that it was unusual. A year after my diagnosis, my other ankle rolled (I have very high arches and wore inserts to support my feet. That sprain took about six months before I could even walk on it and another three before I stopped limping. My sneaker inserts were a big issue. I had to get neutral, padded inserts because the ones for high arches were making my ankles roll out. I though foot drop would soon follow but it hasn't. I can still walk on my heels and toes but it is very hard and I can't support my weight on only one foot.
I finally found sneakers that are more supportive and I'm using thick neutral bottom cushions. I experimented with a bunch of ankle supports but none of them helped.
Both ankles are weak and I have to be very careful walking and going down stairs.
I will definitely look into what Nikki has when I need AFOs.
Even in absence of ALS, when you sprain your ankle once, you are much more likely to sprain it again.
As for discoloration, for the first time in my life my feet swell if I keep my sneakers on all day. So far I've not noticed discoloration except when they were sprained and that eventually went away.
When my feet and ankles hurt, I soak them in magnesium salt, then rub them with magnesium oil and THC topical cream. It makes them feel a lot better. Sometimes I feel like I need the water hot and other times it feels better cold.