We can only speculate. There have been no double blind studies on changing connective tissue using structural integration techniques.
In the beginning of Ida Rolf’s work, Dr. Rolf by experience knew only of working with dead connective tissue. She had worked at the Rockefeller Institute and had over 20 published papers on the nature of (dead) connective tissue.
Because dead connective tissue is very hard, and scalpels of the day had to be sharpened over and over, the idea was there that connective tissue can not be changed with manipulation. Maybe with a cast, or surgery, but not with the hands. Ida Rolf thought that the connective tissue had to be torn to change it, to change its badly aligned bonds, and set about so tearing with her hands.
(In this blog, I am skipping right over WHY Ida Rolf wanted to change tissue therapeutically for organizational reasons.)
Ida Rolf tore connective tissue for some years, and had some amazing results. “Miracles happened around her all the time,” is a common remark from those who saw her work. She insisted that it was technique, not her own skill. She thought ripping tissue was the only way.
However, when Dr. Rolf’s students began to tell her that the tissue was changing and they were not tearing it, Ida Rolf listened. She did have the experience of sometimes not tearing tissue herself, and had learned that there was more to technique than ripping. I once heard Gael Ohlgren, whom Dr. Rolf trained as a teacher in the early days, say that Dr. Rolf’s hands were like clouds.
Dr. Rolf asked David Robbie, M.D, who had trained as a Rolfer with her, to speculate about what was going on.
Here’s the speculation, plus some added since we know more to speculate about now, 40 years later.
When faced with the heat and educated pressure of the human hand, the connective tissue changes its state from gel to sol. In addition, nervous system components of the tissue, including elastin fibers, sympathetic and parasympathetic systems, golgi tendon organs, and sarcomeres of muscles, etc. can be reset. About 24 hours or so later, the connective tissue hardens back to its protective state, retaining a portion of the changes.
Connective tissue is formed by how it is used, and if the structure is functioning better, the connective tissue will take that better function shape.
Last month a learned and wise man died who specialized in study of state changes, Dr. Leo Kadanoff. I wish his feats had included state changes in connective tissue during structural integration. http://www.nytimes.com/2015/11/02/science/leo-p-kadanoff-physicist-of-phase-transitions-dies-at-78.html?rref=collection%2Fsectioncollection%2Fobituaries&action=click&contentCollection=obituaries®ion=stream&module=stream_unit&version=latest&contentPlacement=9&pgtype=sectionfront&_r=0