The psoas is a muscle that has received large amounts of discussion in varying circles. It has been called the “muscle of the soul“. There have been many other suggestions as to connections the psoas has between mechanical dysfunction and seemingly correlated physiological dysfunction…that is not what will be discussed here. Before even attempting to consider possible physiological dysfunctions related to the psoas we have another problem, and it seems like a bit of a big deal, we are not presented with any form of consistent agreement as far as the full functional role of the psoas. The psoas is a muscle of investigative controversy! So, let us take a look at some of the available information and see where it points us.
Muscle spindles (and golgi tendon organs aka GTO) are generally responsible for modulating muscular contraction. There are full on reflexes associated with both the 
An intelligent mind is constantly learning. – An intelligent mind is one which is constantly learning, never concluding – styles and patterns have come to conclusion, therefore they [have] ceased to be intelligent. (Striking Thoughts: Bruce Lee’s Wisdom for Daily Living) 
Osteopathic manual therapeutics are based on mechanical principles. They are often discussed poorly within the profession however they do form the basis of the concept that governs the manual aspects. These concepts hold true in other manual professions as well. These concepts are present in heavy industry, engineering, math, and anywhere else you look.
Classical Osteopathy in Ontario 