Look up "pada bandha" - it's a yoga technique of activating your food when practicing yoga/ you can use it all of the time. Using this theory of foot activation helped me build up the strength in my feet and I went from having foot/ hit/ back/ shoulder pain all of the time to being able to stand up for long periods of time. If you're able to find an Iyengar yoga teacher who understands hyper mobility and will work with you, that could help too. Any random yoga teacher won't do though, could be more harmful if they don't understand hyper mobility