Yep, plain ole’ plastic, just as gh-cidp has described them.
I got my first AFO in 1980. I got my first right sided AFO circa 2006.
As I recall, prior to 2006, no orthotics maker ever offered ‘padding’ for my AFO. Even if they had offered, which they did in 2006, I would decline because.
Because why? Ugh, my legs sweat. For me it’s a personal comfort and hygiene choice.
Instead, prior to getting married, I always shopped around and found knee high socks. After I got married and my wife saw what I needed, she bought thigh high lady’s nylon style stockings (not the kind that ‘runs’ when you look at it), cut them to just over knee high on me and resewed them.
The nylon does several things. It is slippery, my legs slide around easier inside the braces, it protects my skin from rubbing on the plastic (or the padding, if I had any). And, I can change them everyday.
In addition, the nylon is a little bit stretchy so I can fold it back down over the hook & loop style straps which helps keep them closed and prevents my pants’ legs from hitching on the straps and buckles.
I also wear a pair of those ankle high sports socks to make the part where the plastic brace meets the bottom and sides of my feet more comfortable. All of this requires a size or size and a half larger 4E shoe.
At any rate, I could not imagine walking around in water with shoes, or sandals, and braces on. I suppose I’d rather have a walker and walk myself to the water’s edge and then do my water sports thing.
I hope you guys figure something out for your husband.
Personally, I’d have the padding removed.
p.s. speaking of never. No doctor, or P/T ever recommended I get my AFOs refitted. Have your AFOs evaluated periodically in the event muscle loss continues. As gh-cidp stated, AFOs are custom made both as to fit and as to how much support is needed in several key areas.
p.p.s Medicare will pay (I heard) for new AFOs every two years. Might be a reason for that.