As sexologist Robert Thomas explained to Mel Magazine, sex and a corresponding orgasm don’t only build tension in your vagina and pelvic region — it can also extend to other parts of your body, like the muscles in your legs. What happens to your muscles during sex and orgasm (the contraction) actually has a name — myotonia. “When you’ve reached an orgasm, all that built-up tension of the muscles is released,” he told the outlet. This is when your legs shake.
Typically, the leg shaking happens while you’re still in bed. But experts say you could feel wobbly on your feet for some time after too. This may have more to do with having sex in certain positions, particularly ones that require you to tense your leg muscles (think squatting, etc.). Sex is a physical activity, and much like exercising, it requires exertion of your muscles. Now that you know the science behind this post-coitus mystery, how do you handle it when it happens, and are there ways to prevent it?