I would like to genetically modify a human being in one concrete case like I did in other parts of my little series of How would it affect a human to suddenly... This time I would like to add a pretty long foxtail and get a feeling for how much muscle mass would be needed to make the modified human able to move his new tail around.
The foxtail will be an appendage to his coccyx and I would like to ignore the question about How this transformation exactly happened. For this little experiment I want to use simple up-scaled data from the Arctic Fox, which normally has around 55 cm head-and-body length plus 30 cm tail length. To make it easier I will assume that the length of the tail is roughly half the length of the head-and-body. Thinking about humans head-and-body length is quite different from what we normally perceive as height. Still, using the normal height seems convenient and postulating that the human in question is supposed to be around 1.80 metres tall we get a tail with a length of 0.9 metres. Let's pump that up to 1 metre for ease of calculating stuff.
The above shows that I am not really picky about numbers when genetically modifying humans, but I would like to get a feeling for the amount of muscles needed to have control over such a long tail. For example the arctic foxes can, according to the linked Wikpedia article, curl up into a little ball of fur when sleeping so that they won't lose as much body heat. And it would be quite bad if the tail was always dragging around the floor.
I couldn't find any numbers about muscles needed for tail control. Furthermore my knowledge of how tails work in animals is best called rudimentary. I would like the human to be able to control the foxtail in such a way that he can for example wrap it around himself like a little fluffy blanket.
If you need more information about what I have in mind I can refer you to a picture I linked in my first question on the site (The role of anthropomorphic foxes in a medieval army) which is of the League of Legends character Ahri. The picture depicts multiple tails that are far longer than I am interested in for the scope of this question, but it might give you an idea of what I want the tail to look like and be able to do as you can see how the different tails twist in different ways.
If I simply scale a fox's tail to the above size how much muscle mass would I need to add to my human? It would be very nice if answers could compare this number to something else that might be easier to grasp, for example whether this would be more muscle mass than people normally have in their biceps.