达·芬奇认为“运动是一切生命的源泉”，连素描画里的线条也是点的运动的结果。他喜欢用波浪起伏的曲线去安排人物的姿势，就和这一认识有关。对于人的手势和表情，达·芬奇有这样的看法：人在不做作时的动作、手势和表情必定和这人的思想感情相适应。所以，他把动态、手势、表情看成是绘画里揭示人物内心世界的手段，要求画家笔下人物的动作在任何情况下都应当表现它们的思想感情。

Leonardo Da Vinci believed that "motion is the source of all life", and even the lines in the sketch are the result of the movement of points. He likes to use the undulating curve to arrange the posture of the characters, which is related to this understanding. Leonardo Da Vinci holds the view that the gestures, gestures and expressions of a person when he is not acting must be compatible with his thoughts and feelings. Therefore, he regards dynamics, gestures and expressions as the means of revealing the inner world of the characters in paintings, and demands that the actions of the characters in paintings should express their thoughts and feelings under any circumstances.