For many years Keen pioneered the development of safe, effective, wrestling equipment such as the Cliff Keen head guard that bears his name. He is credited with developing the wrestling headgear used to protect wrestlers from head and ear injuries. And in 1955, Keen developed a new circular wrestling ring. At the time of its introduction, the Associated Press reported: “Michigan wrestling coach Cliff Keen saw his brainchild take shape this season – a circular wrestling ring. He has great hopes for it.” The principle behind Keen's round ring was to eliminate the corners. Keen felt it was too easy for a wrestler to reach for the edge of the ring and pull himself out. The corners also restricted movement and made it difficult to maneuver from a corner, because a shift in either direction would put one or the other out of the ring. Keen explained that the square ring was of “mechanical history.” With the ropes used in the 1930s, a square ring was needed because the ropes had to be anchored by posts. With the ropes gone from collegiate wrestling, Keen concluded it was time to free the sport of the squared ring. Keen also teamed with Michigan Track Coach, Don Canham, in 1952 to produce the first film techniques for coaches in wrestling; the films were marketed by Canham's School-Tech, Inc. in 1954. In 1958 Keen founded the company, Cliff Keen Wrestling Products now known as Cliff Keen Athletic, Inc., which is still in the business of manufacturing wrestling gear, equipment and uniforms. Keen was also one of the authors of Championship Wrestling, printed in 1943 while he was serving in the U.S. Navy, 1942–1945; it was a leading book on wrestling technique for several decades. Keen's influence and effect on the sport of amateur wrestling in the United States from the 1930s until present has been incredible and enduring.
