It was at the University of Wisconsin-Madison where Stumpf, working with specialists in orthopedic and vascular medicine, conducted extensive research into ergonomics, specifically in the way people sit.
In 1974, Herman Miller commissioned him to apply his research to office seating.
Later, in collaboration with Don Chadwick, he produced the groundbreaking Equa and iconic Aeron chairs.
Stumpf's death at age 70 was attributed to complications from abdominal surgery.
He was married to Sharon Stumpf, and has five grandchildren: Gabriella, Erin, Max, David and Julia.