Originally, the iron ball was a kind of heavy solid ball in the Song Dynasty. As a weapon, it was used for defending. In theQing Dynasty(1644-1911), the solid ball was replaced with a hollow, chrome-plated steel model, usually with a sounding plate inside that makes a pleasant tone as the balls are rotated.
According to Chinese traditional medical theory, meridians (jingluo) are channels or pathways through which vital energy (Qi) circulates within the body.Acupuncturepoints are also distributed along these meridians. By means of the meridians, the ten fingers are connected with the cranial nerve and vital organs of the human body including the heart, liver, spleen, lungs, kidneys, gallbladder, stomach, and intestines. By stimulating these points with the balls, each meridian is stimulated, which in turn can create better circulation of vital energy and blood within the body.