Tail twitching / spasms?

[Icegoo2]

https://m.youtube.com/watch?v=Fknwe0sBWuc

Has anyone seen this before? This is occurring at least once per hour... Other than this the gecko is healthy.. Eating and pooping regularly. ( Also receiving dusted calcium crickets ) It seems involuntary since I have seen it happen a few times when she was sleeping. (Sometimes it wakes her up and sometimes it doesn't ).
She is quite old though at 16 years...

 

[DrCarrotTail]

She does look fat and healthy. Her limbs look a bit soft and her eyes a bit mishapen - it could be her age but I would lean toward something more sinister like an infection or MBD. The tail twitching is not normal, especially if it just started. I would think there's something neurological going on (which could also be caused by too much or too little calcium) and would get her to a qualified reptile vet. Best of luck! Keep us updated!

 

[Icegoo2]

I brought her into the vet... Turns out it is arthritis and the twitching is because of pain. I'm giving her a daily dose of metacam, it seems to be working so far, the twitching is reduced to less frequently and less violently.