Yes! Photographs taken of clients years after the basic 10-series show changes still present.
Physiology explains why: Our bodies are constantly breaking down and rebuilding themselves. Bodies determine how to rebuild themselves in the future, based on the present way in which weight and stress is distributed through the structure.
When we loosen, lengthen, and shift connective tissue, we affect relationships between structures; we change stress patterns.
Thus, the body rebuilds itself a bit differently. This is how Structural Integration affects structure over the long-term.
Obviously, if body-use changes due to injury, illness, or stress, additional work may be useful.