The one I do not recommend (usually) is isometric training. Basically you hold your breath and pit one part of your body against the other. This raises blood pressure, which might be good in OI, but I have to watch my bp going too high as well as too low so I avoid this. There should be plenty of internet guides on this though I have not looked.
The other one is similar but from chinese martial arts: dynamic tension. Bye, Alex
I'm not sure who taught you isometric but it doesnt have to be pit against each other and you can breathe through it. I like pressing against a wall in various positions to strengthen joints without having them in less stable positions.
I like dynamic tension ones, i think they are great. Theres a reason its part of a meditators relaxation techniques.
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xrunner,
I'm getting tested for Marfans syndrome later this month, i'm tall but i'm not skinny to that degree, probably due to a healthy regime of exercise. Hyperflexibility is an indicator with that.
Have you ever had your calc/magnesium levels checked? Are you tall and skinny? Could be a needle in a haystack.. just checking.