When Ida Rolf devised the ten-session series of Rolfing, there was no scientific theory behind it; it was built on her own background in yoga, osteopathy, the Alexander Technique, and the like. The one who gave Rolfing its scientific grounding was Hubert Godard, a French Rolfer who teaches at a university.
How do the muscles work against gravity? And why is Rolfing effective? Pursuing these questions to their roots, Godard considered what happens within the body in order to maintain the quality of the muscles under the environment of gravity (“keep tone” of the muscle).
His thinking crystallized into the theory of Tonic Function. “Tonic” means sustained — translated literally into Japanese, it means to work continuously. Godard focused on the function of the muscles that work continuously against gravity. He divided the muscles into the Phasic, which work transiently, and the Tonic, which work continuously.
The Phasic Muscle is a transiently working muscle, involved in sprinting, weightlifting, lifting objects, and the like. It works when lifting something with effort, and it uses glucose as its energy source. Because of this, fatigue sets in and the body grows tired. The Phasic Muscle is governed by the alpha motor nervous system (alpha motor neuron). Because the alpha motor nervous system is one of the nervous systems operated by the human brain, the brain can influence it directly. Alpha makes up two-thirds of the motor nervous system. When tension grips the body through daily stress, the Phasic Muscle works as the central player as well.
The Tonic Muscle is a continuously working muscle, said to be involved in maintaining posture. Because it uses oxygen as its energy source, it works slowly and continuously, and so it is rarely overcome by fatigue. A feature of the Tonic Muscle is that it holds many muscle spindles. A muscle spindle is a sensor of the muscle — a sensory organ that detects the stretching and shortening of the muscle. The instruction in yoga or meditation to “bring awareness to the body” can be thought of as switching on the muscle spindle. Because the muscle spindle works through gravity, the spindle-rich Tonic Muscle can work automatically even without consciously attending to gravity. It is governed by the gamma motor nervous system (gamma motor neuron). Gamma makes up one-third of the motor nervous system. A feature of the gamma motor nervous system is that it begins to work through habituated movement by way of the cerebellum, the medulla oblongata, and so on.
Another feature of the gamma motor nervous system is that it can engage only the necessary muscle without engaging the antagonist. Reciprocal inhibition exists among the muscles. The body is built so that, when one tries to relax a muscle one actually wants to release — say, the hamstrings at the back of the thigh — putting force into the opposing quadriceps (the muscle at the front of the thigh) relaxes the hamstrings. In the arm, too, when the biceps is contracted, the muscle behind it is relaxed. This is called reciprocal inhibition of the muscles (the hamstrings are the antagonist to the quadriceps). With the alpha motor nervous system, the antagonist begins to fire.
Also, to activate the gamma motor nervous system, a state in which kinesthetic sense is being used is important. In Rolfing, this is also called Haptic / Palpatory, and it means: whether the external sensory organs — including the hands, the feet, and the head and face — can firmly receive external information and convey it into the interior of the body.
Rolfing comes down to this: how to activate the gamma motor nervous system and make the fullest use of the energy-efficient Tonic Muscle within the body. It can be said that the ten sessions are constructed for this very purpose. For this, the practitioner, too, must have an ordered body and a working gamma motor nervous system. Sharpening bodily sensation through embodiment is also a way of activating this nervous system.
Come to think of it, 95% of the human body is devoted to gathering information about the external environment; the remaining 5% uses muscular force. Considering that today’s world has become dominated by the alpha motor nervous system, the need for Rolfing feels very great.
What is interesting about Godard’s analysis is that he considered the Tonic Function centered on the Tonic Muscle to be influenced by four factors: structure (the body’s posture and composition, gravity, and so on), coordination (how the body moves), perception (how the world is seen), and meaning (how meaning is assigned to the world). Viewed in this way, Tonic Function becomes an idea that connects mind and body.
In the Rolfing training, Giovanni explained that Rolfing works on structure, the Feldenkrais Method on coordination, the Alexander Technique on perception, and counseling on meaning — each changing Tonic Function in its own way.
Tonic Function is an important idea in Rolfing, so I would like to take it up over several installments.