Dystonia

[crunches]

My 3 year-old daughter often does this thing we call "crunches." I have no idea if it's a normal childhood thing, or if something is going on. It usually happens when she is trying to relax, i.e. before going to sleep, and also when she's focusing on something and having independent quiet play time, ie. looking at a book. This is always in a lying down position: She tenses up her legs so that all the muscles are tight and her legs are next to each other and almost crossed, and her feet are turned inward. She also puts her hand in between her legs. She holds her breath for several seconds and gets extremely sweaty. If I tell her to stop, she can make herself stop, but it's almost like she can't stop this urge she has to do it. Thanks for your input!