I didn’t pick the name. It was used by an embryology researcher, Erich Blechschmidt, and was picked up from him by craniosacral osteopath James Jealous, for a 10-year training in gentle touch and presence to assist relaxation as you say. It is a branch of craniosacral therapy. It has nothing to do with the farming method that goes by the same name. It has actually been coined way earlier:

” In September 1866, a seminal monograph authored by the German zoologist and evolutionary biologist Ernst Haeckel was published under the title Generelle Morphologie der Organismen (or the General Morphology of Organisms). In this 2-Volume-monograph, Haeckel not only introduced novel terms and concepts, such as Protista, Monera, ontogeny, phylogeny, ecology and the ‘biogenetic law’, but also coined the word “Biodynamik” (biodynamics) as a synonym for ‘general physiology’. Haeckel (1866) separated the natural sciences into the major branches I (Abiology or anorganology) and II (Biology or life sciences). In Haeckel's scheme, biology (zoology, protistology and botany) consisted of biostatics (morphology) and biodynamics (physiology).”

https://www.tandfonline.com/doi/full/10.1080/15592324.2016.1...