H. arizonesis... About to molt?

So I've noticed Mallatobuck, my H. arizonensis, in this position a lot when I get home from work and check on my scorps. She's standing perfectly still for long periods of time, on point, with her legs stretched out, back arched. A lot of times she has her tail up, with the telson resting on her "head", also appearing to be stretched out in an arch position. Is this a good indication that she's about to molt? Maybe stretching the exoskeleton out so she can get out of it?

It also reminds me of the position that I have seen females get into when they are birthing, but no scorplings have ever come out (I have observed this 5 or 6 times in the past couple weeks) and I haven't noticed any embryos visible through her sides. She's incredibly thick, but by the way her plates appear to be pointing out, and the lack of visible embryos, it looks to me more like she's pre-molt than gravid. I could be wrong though. What do you guys think?

My female is doing exactly the same. Thats a sign of an imminent moult

Does it flick the tail too?

Not that I've seen. She just stands perfectly still.

could be, or just basking. Based on the picture the "side tail" is a good sign a molt is approaching.