R. Dan Allen is the president of D. A. Surgical and is recognized as an authority on patient positioning and pressure management in the operating room. He has dedicated more than forty years to the study of anatomy and physiology relating to surgical patient posturing and positioning. He has invented and commercialized standard of care patient positioning devices including: the Allen Stirrup and many of its iterations, a unique Trendelenburg positioner, a 'no tuck' arm restraint, and a comprehensive range of robotic surgery positioning devices. Dan is a published author and has addressed hospital staff, OR nurse, and surgeon assemblies around the globe.