No, even if the hands don't move, the brain will still develop. Most of the development of the brain is determined by genes, and perhaps some of it is acquired. But hand movements only exercise the motor area of the brain, and even if they have an impact, they are very, very small. Using logical areas more may make you smarter. But in mathematics and physics, not only the brain should be smart, but also the thinking method of solving problems should be learned. When you do the problem, you should move and review. Don't underestimate review. Most of the thinking methods are written down during review. . .