I found this in my "pile" of stuff.
"Hu Yaozhen(1879-1973). Hu was an esteemed practitioner of Chinese medicine, martial arts, and Daoism and is generally considered "the father of modern qigong." He helped to standardize the term qigong as a substitute for the wide array of ancient words commonly used for Daoist qi cultivation (e.g. daoyin, yang sheng, nei gong, tuna)."
When I first learned qigong, in the form of iron shirt, it was referred to as nei gong. I was told it just meant "inside" work. There was a counterpart called
hei(pronounced hay (sp?)) gong, that was "outside" work, describing external qigong. I learned a form of Shaolin exercises once that were a set of isometrics. I felt the concentration of work was focused on the muscles, and also had some deeper development to it, but I always thought of it as an "outside" form of qigong work.
The quote I mentioned, went on to say that Hu also coined the phrases tranquil qigong (jing gong) and active qigong (dong gong), to distinguish qigong meditation (inactive) from active qi gong(dong gong). Also the first to use qigong in a clinical setting, according to this source...
