Born in Chicago, Illinois, Yocum earned his undergraduate degree at Western Illinois University in 1969, his medical doctorate at the University of Illinois in 1973, after which he completed both his internship and residency at Northwestern University in Chicago.
Yocum gained prestige by extending the careers of several Major League Baseball players, by repairing injuries that once would have ended their playing days. He also served as the team physician to the Los Angeles Angels major league club during 36 years, and was a specialist consultant to numerous dance companies based in Los Angeles.
Specialized in sports medicine, shoulder, elbow and knees, Yocum worked along with Frank Jobe, who performed the original Tommy John surgery. He was also a panel reviewer for the American Journal of Sports Medicine, a board trustee at Centinela Hospital Medical Center, and authored numerous publications and books. The Los Angeles Kerlan-Jobe Orthopaedic Clinic was founded by Jobe, who shared the workplace and a close friendship with Yocum for 35 years. Along with James Andrews, Yocum and Jobe became the most renowned orthopedic surgeons for professional sports people.
The careers of countless big leaguers benefited from Yocum's expertise, among others pitchers Ted Lilly (knee), Stephen Strasburg (Tommy John), C. J. Wilson (elbow) and Jordan Zimmermann (Tommy John), as well as outfielder Jacoby Ellsbury (ribs), slugger Kendry Morales (leg repair) and infielder Dustin Pedroia (foot).
In May 2013, the Angels club named their training room in his honor, with pitcher Jered Weaver placing a placard with Yocum's name above the room's door in the clubhouse. Although Yocum never operated on Weaver, the pitcher often talked with him about anything he was feeling.
Yocum died in Manhattan Beach, California at the age of 65, following complications from liver cancer He was married to whom he referred to friends as "the love of his life" Elizabeth B. Yocum with whom he had two children with: Donald James Yocum and Laura Elizabeth. Dr. Yocum also leaves behind a granddaughter name unknown, but whom sources state was the joy of his life. He will be greatly missed by his family, friends, and anyone whom had the pleasure of coming in contact with him God Rest His Soul In Peace
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- "Kerlan-Jobe Orthopaedic Clinic – Lewis A. Yocum. M.D.".
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- Matuszewski, Erik (May 28, 2013). "– Los Angeles Angels MLB Team Doctor Lewis Yocum Dies". Bloomberg.com. Retrieved March 7, 2014.
- "Espn.com – Angels orthopedist Lewis Yocum dies". Espn.go.com. May 28, 2013. Retrieved March 7, 2014.
- New York Times obituary