In 1969 he founded the first school for therapists to learn the method of the Manual Lymphdrainage. A couple more of these schools were founded later on.
Asdonk was born in 1910 as a farmers' son in the town of Kamperbruch in the lower Rhine regions. He finished school in 1929 and studied theology for two Years in Müster and Tübingen. In 1931 Asdonk started studying Medicine in Münster finishing it in 1936.
He worked as doctor in the sickbay during his military services during WWII. In 1945 he founded his own ambulance in Rheurdt in the lower Rhine region. In 1956 he changed the location to Essen.
In 1963 he got to know the Manual Lymphdrainage according to Dr. Emil Vodder. He was fascinated by this treatment, since it helped in combination with massages and Chirotherapy to release the burdens of his patients for a longer time.
In 1969 he founded the first school for therapists to learn the method of the Manual Lymphdrainage. A couple more of these schools were founded later on.
In 1972 Asdonk gave up his ambulance since the amount of patients was no longer managable. He founded the world's first clinic specialized in lymphology in Saig in the black forest, which was acknowledged by the state of Germany in 1973. In the year of 1974 his therapy was acknowledged by the health insurance companies, who would from now on come up for the costs of the treatment. In 1975 the clinic moved to Feldberg, the reason why the clinic was called "Feldbergklinik" ever since. Until the year of 1978 Asdonk was the only doctor working in the clinic. In 1983 the clinic moved once again, this time to St. Blasien in the black forest. In 1984 he ritired in the age of 74. From this point on his son in law, Werner Beck, acted as the CEO of the clinic. Later on in the year of 1995 Beck built and opened another clinc specialized in lymphology in Dorf Zechlin / Brandenburg.