Chinese therapy balls

The therapy balls, known as one of the "three treasures" of a province in China, is a traditional product that has been produced since the Ming Dynasty (1368-1644), and has been made by Chinese craftsmen for the past 300 years.

Originally, the Therapy Ball was a solid ball of jade or marble but later was designed hollow with a sounding plate in it when technology permitted.  Sold in pairs, one sounds high and one sounds low.  It is a form of exercise to build strength and increase circulation in the hands and arms.   As a conditioning apparatus for older persons it is one of the simplest ways to tone the joints and muscles in the hands, forearms and shoulders.  It is an especially convenient method of obtaining relief from such afflictions as minor arthritis, tendinitis, carpal tunnel sydrome [sic], thoracic outlet repetitive strain injury (RSI), computer strain and other hand/arm/shoulder neck related discomforts.  Many people simply do their "exercises" while watching TV.  It is also a relatively effortless way to increase hand and forearm strength for people participating in weekend sports activities such as tennis or golf.

According to the traditional Chinese medical theory of "Jingluo" (Jingluo refers to the main and collateral channels, regarded as a network of passages, through which vital energy circulates and along which acupuncture points are distributed), the ten fingers are connected with the cranial nerve and vital organs of the human body, including heart, liver, spleen, lungs, kidneys, gall bladder, stomach and intestines, etc.  When moving the iron balls with the fingers, the balls can stimulate the various acupuncture points on the hand, resulting in increased circulation of vital energy and blood in the body.  "It can cause the jingluo (channels) to be cleared, the vital energy and blood to function in harmony, the muscles to become nimble [I'm guessing the word is nimble, but there's a hole in the paper], the bones to strengthen, the mind to clear, the circulation to improve, and can prevent and relieve hypertension and various chronic diseases.  If you keep exercising everyday for months and years, you can get the fine results of keeping your brain in good health with high intelligence and good memory, relieving your fatigue, drowning your worries, and, moreover, prolonging your life."

To exercise, put two iron balls on your palm, and crook and stretch your four fingers and thumb in sequence to cause the balls to rotate and revolve either clockwise or counter-clockwise.  All the joints of the hand will always be in motion; and with the crooking and stretching of the fingers, the forearm muscles are contracted and relaxed rythymically [sic].  At first, you may prefer balls of smaller size for exercise; but as your hand strength and dexterity increase, you can use larger and heavier balls.  You should exercise both hands alternately, and will be amazed at how soon your fingers "learn" to move the balls around your palms.

[transcribed from the "Something Special" instructions, but there were some small holes in the paper, so my transcription might not be 100% accurate]