MDF® Tromner Neurological Reflex Hammer with Built-In Brush for Cutaneous and Superficial Responses The MDF® Trömner Hammer (aka Tromner or Troemner) is a versatile 3-in-1 dual mallet-type reflex hammer designed for eliciting myotatic and cutaneous responses in adult and pediatric patients. This popular reflex hammer was invented by Ernst L.O. Trömner, MD, a director of the Neurological Hospital at St. Georg and professor at the University of Hamburg. The balance-weighted stainless-steel head is outfitted with large and small mallets constructed of soft silicone for precise percussions. The weighted stainless-steel handle is precisely balanced for increased control of force for percussion. The tip at the base of the handle elicits superficial or cutaneous responses, including plantar and abdominal reflexes.