You may be asking what is this really weird word and why is your hand like that? Well My muscles spasm to the point where my hand and arm lock into this odd position and my Dr dubbed it Dystonia. The Dictionary says its "Abnormal tonicity of muscle, characterized by prolonged, repetitive muscle contractions that may cause twisting or jerking movements of the body or a body part." Or "A disabling neurological disorder in which prolonged and repetitive contractions of muscles cause jerking, twisting movements and abnormal postures of the body" Now mine is said to be caused by FND (Functional Neurological Disorder) and i have benefitted from the recommended treatments for Dystonia as my quality of life has improved quite a lot.
Dystonia can be caused by many different things not just FND so don't take my experience as the end all say all as it can be the result of, head injuries, stroke, neurodegenerative disease, certain infections, birth defects, med reactions, etc. Also different treatments have different effects on different people as there is no universal way to approach it. People also experience it in different ways due to the different locations and pain tolerances. This doesn't make anyone's experience less it just makes them all unique.
With Dystonia You can also struggle with dystonic attacks where your entire body just locks (this has been the artists experience anyway) and gets stuck. its painful, you cant move, sometimes your face and eyes lock to the point you cant speak or see as well. It can be very terrifying during the bad ones. However its Important to breathe and not panic. Generally the Artist only deals with dystonia in her left leg and left arm but will have random attacks on her face and with her neck other arm and leg. It is not nearly as bad as it used to be as she used to refer to her arm as a dino arm and now the only thing locked is her pinky on her left hand. It has taken a lot of work to get there and there are times her arm does lock back up but they are short lived.
if you want to read a bit about Dystonia check out this link.