The Vasyli McPoil Tissue Stress Relief pre-fabricated foot orthotic is the result of the collaboration between Vasyli Medicals Innovation Director, Chairman and Podiatrist Phillip Vasyli and Prof. Thomas G. McPoil PhD, PT, ATC. Its design incorporates intrinsic features based on the McPoil - Hunt Theory of Tissue Stress. Essentially, the orthotic incorporates a dual density approach using a sifter density overlay material to allow for what Tom calls the normal amount of pronation, while preventing over or excess pronation with a higher density orthotic shell.