Yang Lu, a clever doctor, how did he cure the stubborn disease of King Younan?

Play ball. Yang Lu, a clever doctor, cured the stubborn disease of King Younan by playing ball. Several kinds of medicinal materials are made into curved sticks, then hollowed out like reeds, filled with medicine and finally made into balls. The next day, he met the king and suggested that he ride a horse and play ball. When the king came to the square, the imperial doctor took out a stick and said to him, "Your Majesty, take this stick well, hold it like a fist, and then ride a horse and hit the ball hard until your palms sweat and your body produces fluid." Drugs will spread through the palm of your hand. When you are sweating and the medicine works, take a bath and sleep immediately. "