Gerda Momsen was born in Bergan to Richard (a librarian) and Magna (a designer, sportswoman and businesswoman); her grandfather was a schoolteacher and local politician.

In 1947 she enrolled at the University of Oslo to study psychology[1] and received training as physiotherapist which led to work with Aadel Bülow-Hansen.

In addition to client-oriented work other focus areas were included, she was the first woman in Europe to establish her own psychotherapeutic training institute.

She came to the conclusion that certain massage techniques could bring to completion the expression of unwanted feelings, or "incomplete cycles," and this release of emotional charge would entail similar noises from the intestines as during digestion of food.

She could allegedly differentiate a multiplicity of peristaltic noises, diagnostically arrange and make inferences on the subconscious processes of the clients.

[7] In this manner the client is to be encouraged to discover his or her own mental experience (introspective ability), to follow and to express his or her bodily-psychological impulses.

It is a special kind of massage aimed at affecting "deeper layers" of the unconscious mind, which is supposed to contribute to attitude changes, physically as well as psychologically.

The claim in Body psychotherapy is that psychological trauma is embedded as a process of body and mind and causes not only mental changes and mental constructions of defense mechanisms, but also physical changes in posture, breathing, movement ability (motility), muscle consistency, changes in the functioning of the autonomic nervous system and other biological processes.

Through psycho-postural work there is a 'removal' of some of the physical elements of the defense mechanisms, a process that allows repressed trauma to emerge into consciousness spontaneously.

[8] The Primary Personality is the term used to describe the well-functioning individual, in harmony with the flow of life; self-regulating, and aware of what Gerda Boyesen called ‘universal values’.

Like most body psychotherapeutic schools, Biodynamics is not recognized by the health insurance companies in the United States as a scientifically based therapeutic intervention.