Color Psoas with Pars Vertebralis Published June 11, 2014 at 484 × 414 in Does Psoas Cause Lordosis? Three Layers of Psoas and their affect on the lumbar spine & discs Continue reading → The 3 layers of psoas have someaht different actions on the lumbar vertebrae. PLEASE SHARE THIS!TweetMorePrintEmailShare on Tumblr