Cantwell graduated from Little Rock McClellan High School in 1996. He then served in the United State Air Force from 1967 to 1971 and worked with his father before returning to college in 1980. He graduated with a B.S., ED with specialization in Athletic Training form Southwest Texas State University in San Marcos, Texas in 1983.
In June of 1983, Cantwell was employed by Holt Krock Clinic in Ft. Smith, Arkansas where he was the first athletic trainer in Arkansas to work for an orthopedic group. He was also responsible for the athletic training programs at Ft. Smith Northside and Ft. Smith Southside.
He continued his career with Parker Orthopedic and Spine Institute in Van Buren, Arkansas in 1986 where he was given the opportunity to start programs at Westark College, Arkansas Tech University and Ft. Smith Gymnastics and employed other certified athletic trainers to work with local schools and recreational programs. Cantwell also became an associate with the Justin Professional Rodeo Sport Medicine Program.
After returning to his hometown of Little Rock, he went to work for Martin Knee and Sports Medicine. Cantwell began the athletic training programs at Little Rock Catholic high school, University of Arkansas Monticello, Harding University, Hendrix College and helped secure the programs at Henderson State University and Ouachita Baptist University in Arkadelphia. During the summer he worked with American Legion baseball in the Little Rock area.
Cantwell then had the privilege to work for Arkansas Orthopedic Associates and Dr. Herb Hahn and established a module rodeo sports medicine program. He had the opportunity to work with rodeo contestants form high school to the professional level. In 1998, Arkansas Orthopedic Associates merged with three other clinics to create OrthoArkansas, one of the largest orthopedic clinics in the state. He is the Head Athletic Trainer and responsible for the athletic training programs at Little Rock Catholic, Little Rock Hall, Little Rock Parkview, Little Rock J.A. Fair, Central Arkansas Christian and area rodeos.
He is a charter member of the Arkansas Athletic Trainers' Association as well as past president. He is certified by the NATA and licensed by the state of Arkansas.
Cantwell is married to the former Kathy Wilson and has three children: Josh, Lindsey and Molly. He also has one son-in-law Kevin Warren.