Mr Anderson injured his ankle playing cloth dodge ball at the tournament this past weekend in Dunedin.
Cloth dodge ball is a variation of traditional dodge ball where the ball is heavier and instead of a halfway line there is a neutral zone.
Mr Anderson’s injury happened while attempting a "suicide" shot where a player could throw the ball at the opposition while jumping into their zone.
If the player connected then they could stay on the court, but if they missed, they were out.
"I was doing those all day long and then absolutely caned a guy, but then got distracted by someone else and then came down on my ankle wrong," Mr Anderson said.
He said he was in instant pain and he had to take about two weeks off work.
Mr Anderson’s team, the Dunedin Ducks, nonetheless claimed the silver medal in the mixed grade and the bronze medal in the men’s grade.
The duo, other brother Isaac and sister Brenna Gould made up two-thirds of the six-a-side team.
Mr Anderson said they had a great sibling dynamic, but it quickly turned into a sibling rivalry when they played each other.
Isaac had a weapon for an arm that could launch the ball at 120km per hour, Mr Anderson said.
"It’s fun playing against him, but he just targets his own siblings."
