Psychology says people who shake their legs while talking aren't rude or impatient: They may be trying to regulate energy without realizing it

Psychology suggests that seemingly small habits often reflect deeper underlying processes. Leg shaking is rarely an act of rudeness or disrespect, and it is not always a sign of anxiety. In many cases, it is simply the body's way of responding to internal energy, concentration or emotional states.

Raccontata daeconomictimes.indiatimes.com