Approximately 4 1/2" around
Harmony balls are usually used for exercise and meditation, but are also good when employed for medical reasons. To use them for exercise, place two Harmony balls within your palm then rotate them clockwise and counterclockwise. Gravity will help you keep on controlling the balls. There are many exercises possible. One is trying to not to let the balls touch one another during manipulation, as advanced users do. Such users of Baoding balls can frequently use more than two balls at one time. Manipulating the balls in your hand not only exercises hand muscles, but forearm and shoulder muscles as well.
Alternative Medicine advocates believe that the balls are beneficial for medical reasons when they touch pressure points or acupuncture points found all over the hand. A practitioner of western medicine would find it hard to believe that such balls have health benefits, but it helps to realize that practitioners of Chinese medicine believe that all bodily systems are linked to one another. Chinese medicine advocates believe one should not just treat symptoms but rather should examine the root cause of the symptoms. In connection, Harmony balls could be prescribed by a Chinese doctor with a patient whose internal energy or Qi has stagnated and thus, caused the problems for the patient. Disorders such as hypertension, arthritis of the fingers and wrists, as well as numbness and trembling of the hands can be prevented and improved through the use of chinese health balls.
The balls harmony follow certain principles involving touching the meridians (just like in acupuncture or shiatsu massage). The meridians (known as Jingluo in Chinese traditional medical theory) act as channels or pathways via which Qi (vital energy within each person) moves throughout the body. These Jingluo meridians also feature the acupuncture points. Hence, touching each meridian will produce health benefits. Your ten fingers are interconnected with the human cranial nerve, as well as important human organs such as the intestines, stomach, gallbladder, kidneys, lungs, spleen, liver and heart. Thus, when the meridians are stimulated, there is improved circulation of vital energy and blood in our bodies.