I too have some similar symptoms to this. My right hand forms that claw formation you discussed and it gets worse with activity – particularly my index finger and my pinkie curl toward my palm the most. This happens most of the time as of recently. I had this happen about seven months ago but then the symptom eased up for awhile, but now it has returned. It also happens in my left hand, but not to as great of as a degree. I have what looks like an essential tremor in my hands and have had it for a year, but tests showed it wasn’t. I’ve begun getting episodes where I lose sensation in my feet and sometimes hands which doesn’t get relieved with standing up or moving around. I had a brain MRI last year which didn’t show anything, and I ended up having a spinal tap a month ago which had oligoclonal bands but they were in both my blood and my CSF, so no one has been able to tell me what that means other than some vague guesses. I’ve always wondered about the tremors and my hand being unable to straighten out – it’s been unexplained for awhile and has really made it difficult for me to do some tasks.