PT400M The PT400M is the most advanced massage table on the market. It provides excellent access to your clients while providing comfortable support. The powered center break in prone opens up their back muscles and relieves pressure in the lower back. In supine, it takes the pressure off their lower back and creates a gentle abdominal stretch. The powered center break also allows you to continuously stretch muscles in side lying, prone, and supine by slowing raising the center as the session progresses.