Polkinghorne possesses an exceptional leaping ability thanks to his volleyball background with St. Bernard's College and for the U15 Victorian schoolboys side.
Polkinghorne is a high possession winner and utility player who excels at the stoppages. He represented Vic Metro at the NAB AFL U18 Championships. In 2007 he made his senior debut with Coburg in the Victorian Football League as part of a trial program. Runner-up in the Calder Cannons' Best and Fairest award for 2007, he is the son of former Hawthorn player Robert Polkinghorne and nephew of Hawks star David Polkinghorne.
He is often compared to Adelaide's Jason Porplyzia due to similar playing style and scoring ability.
Polkinghorne received considerable media attention for kicking a match winning torpedo goal from the centre square in the dying minutes of Brisbane's Round 10, 2012 victory over ladder leaders West Coast.