Is this normal?

Hey guys I need your help! This is Ulani I've had her for 8 years now and l've never seen her do something like this before (video) she did this a couple times and then just went back underground. I'm a little nervous about this though because she's in the process of shedding but it looks like she might be having a little difficulty and now this. It's just all abnormal with her. Does anyone have an explanation of this