Twisting the pen is a technique of calligraphy.
Twisting the pen is an effective way to strengthen expressive force. When twisting, it is generally used in conjunction with the wrist (side wrist). For example, the wrist pillow is too dead to twist (the radian is not enough). However, generally speaking, the pillow wrist is used to write small characters, and even if the pen is not twisted, the expressive force is still sufficient (or there is no need to twist the pen greatly), so it is rare for the pillow wrist to twist the pen.