The doctors you've seen apparently didn't find anything, but if you think you have an issue you might need better docs. But some people just bump into stuff and fall a lot. My wife is like that, she's often bumping into stuff, tripping, turning ankles. Some people also have weak ankles and wrists, which could indicate a nutritional problem or some other problem or just bad luck. Hard to know. Do you ever feel dizzy when this happens? Do you have a balance problem even sometimes when you don't fall? Such things are signs of a problem.
Also don’t know I’m falling until I’ve fallen.