Nah, that's pretty common for people who draw a lot. You might think they are just moving a pen around but you could end up with very gruesome injuries, that will completely take you out of ability to do anything for months. Repeated motions with the same muscles that were never meant to move 24/7 with no breaks, instead of snapping in one go slowly wear and tear and then break entirely. Coupled with not moving and often finding yourself in the same position for hours with your entire body aching and blood flow obstructed to important areas