In September 2020, Knaub started a fundraising campaign, The PCH Cleanup Project, to encourage people to just make the time to spend some time outdoors during the COVID-19 pandemic and pick up litter.
In 1978, Knaub was sitting on his motorcycle waiting for a traffic light to change when he was hit from behind by a car. As a result, Knaub broke his back and was paralyzed from the waist down.
Won the Push Rim Wheelchair Division of the Boston Marathon five times. Knaub set a world record in the 1982 Boston Marathon.
He was a semifinalist at the 1976 Olympic Trials and had set his sights on making the 1980 Olympic team.
Knaub was a pole vaulter at Long Beach State with a personal best of 17 feet, 7 inches.