ABSTRACT Dr. Ida P. Rolf’s development of Rolfing® Structural Integration (SI) implied but did not explicitly address the issue of stability and the relationship of psychological and physical stability in the manner that modern science makes possible. The tonic function model permits a re-examination of Rolf’s Ten Series to make stability and security an explicit part of the offer. Peripheral stability summarizes key features of this re-examination and re-formulation.