Scientists have discovered the mechanism by which light touch body massage works. This article concentrates on the Peripheral Nervous System, and how the benefits of a massage are maximised by using the correct speed and pressure.

Regular visitors to a local spa or other professional massage service are aware that there are many different types of massage: deep body, Indian head, light body touch, and many others. The deeper, higher pressure massages, work the muscles fairly aggressively, and are intended to release lactic acid and other chemical by-products from the muscles. (Lactic acid is a chemical product of respiration in the muscle cells). Lighter massages work in an entirely different way.

An article published in Nature Neuroscience in April 2009 explains why a light touch massage gives pleasure. The team of Loken et al. [1] found that a particular class of nerve fiber specifically sends pleasure messages to the brain. The sensation of pleasure is produced when the hands move at a speed of between 1 and 10 centimeters per second, with an optimum stroke speed of about 5 cm per second (2 inches per second). They found that if the speed of the massage stroke is not correct, no pleasure is felt, and they noted that the effect is only produced with hairy skin. It has also been pointed out that the speed and pressure of the massage stroke is the same as that used by a mother to comfort a baby, or that used by a couple when showing affection.

The particular nerve fibers that transmit the feelings of pleasure are called "low threshold unmyelinated mechanoreceptors". These are nerves that have no myelin covering, and usually conduct signals to the brain relatively slowly. The particular sub-class of nerve that is responsible for the effect found is the "C-tactile" nerve fiber. Some proponents of acupuncture like Campbell [2] have been aware of the role of C-tactile nerve fibers even though acupuncture is generally thought to rely mainly on "A delta" nerve stimulation. ("A delta" nerve fibers convey information about pressure and cold to the brain).