I don't know if this is a correct term, but I have often referred, "Gumby ankles". Gumby ankles are ankles you roll often, but they roll right back into shape and you don't sprain anything. I have really long thin feet and fairly thin ankles (not in proportion), so it's easy for me to hyper-supinate my ankles (correct term?) and fall to the ground. The falling i guess is a nervous system reaction to take all weight off the ankle so I don't sprain or break it. I've done this hiking in boots (not properly tied), running, but most often it occurs when I'm barefoot. Can't say its caused me any trouble though honestly, but it freaks people out when it happens. Anyone else have this issue? I was surprised to read that it is a heredity disorder.