To cross your legs at the knee while sitting is almost second nature for some. As West Side Toast Masters highlights, it can even be an important type of communication, often indicating nervousness or submissiveness. But you might want to find a new way to say “Yes, master” if new research indicating crossing of the legs to be harmful is true. For one, as reported by the BBC, crossing your legs can put pressure on your leg’s peroneal nerve at the back of the knee. This can temporarily impair the sensation in your lower legs and feet. Sitting cross-legged on the floor is even worse, as one Korean study found. In this case, sitting cross-legged on the floor for hours at a time can lead to peroneal nerve palsy, which leads to “foot drop,” where the front part of the foot and toes cannot be lifted.