Shiatsu (acupressure massage) evolved from traditional Chinese Medicine, brought to Japan, and it means, literally, 'finger-pressure'. It was linked to the 'palpation by feeling' (setsu-shin), part of diagnosis, of acupuncture and herbalism. A focus on the state of the abdomen became a strong aspect of Japanese Traditional Medicine (known as Ampuku).The Japanese also had traditional folk massage techniques known as 'Anma'. They kept developing a sense of the connection of touch to assessing and maintaining health.
The ancient Chinese arrived at the concept of 'Yin and Yang', arising from one over-riding source of energy, the interplay of which they saw as creating all life, objects and events.
They further described what they observed about energetic patterns as 'Five Phases of Energy' which are thought to work in the human body in a correspondent way to how they work in the world around. In Chinese medicine these forces are described as: wood, fire, earth, metal and water and they connect to organs, emotions and functions in the body and being. They are seen to work in a generative, helpful, way when they are in balance, but can become imbalanced and stress the system. Imbalances can come from environmental conditions, diet and activities and from emotions
The name that the Japanese have for 'energy' is 'Ki', and shiatsu/acupressure works on harmonising the flow of Ki in the body: the aim is to help get energy working so that nothing is too 'full' ('jitsu') or too 'empty' ('kyo'), but at the right level to be helpful. Traditional Chinese Medicine works on a system of acupoints - or 'tsubos' in Japanese - which are like little connection buttons into the systems of the body and its organs and functions.
'Shiatsu' as we have come to know the combination of tCM and Japanese palpation and massage techniques was especially developed in its modern form by two key recent Japanese practitioners and teachers: Tokujiro Namikoshi and Shizuto Masunaga, but it was first defined in the early 20th century, in an attempt to preserve Anma and Ampuku techniques alongside the input of Western Medicine.
Shiatsu is closely linked to the practice of Chi Gung (a simpler version of Tai Chi) if you'd like to try some Chi Gung you can find links to some good and easy to follow YouTube videos via the Links Page.