Career
First he broke the record set by Christos Papanikolaou of Greece and San Jose State University two years earlier, by jumping 5.51 metres in Austin, Texas, becoming the second man to clear 18 feet. A week later he improved it to 5.54 m in Los Angeles, California. His technique inspired several aspects of the Petrov/Bubka model.
Two months later he added another centimeter at a meet in Helsingborg, Sweden.
Isaksson set his personal best at 5.59 m in El Paso, Texas, on 23 May 1972. Isaksson competed at the 1968, 1972 and 1976 Olympics with the best result of tenth place in 1968.
In 1972 he was handicapped by a sudden change of rules by the IAAF and could not clear any height. He appeared on the cover of Track and Field News several times starting in April 1971, then March, April and June 1972 (with Seagren).
He dominated the European competition in 1975 and 1976, defeating the British Superstar David Hemery twice, and scoring 56 points (out of a maximum 80) in the 1975 final.
Isaksson was particularly strong in the running events (where he would only be allowed to compete after giving away "handicaps" to his rivals) and the gymnasium. He would gain extra points in weightlifting contests by lifting higher weights in proportion to his body weight than his heavier opponents. This gave him a major chance in the 1977 World Championship, though he was hindered by the IAAF disqualifying him from professional athletics competition (and thus the running events).
Now retired from athletics, Seagren was free to compete in the running events and scored enough points here to beat Isaksson into second place. record.