As Tumble Circus gears up to celebrate its 30th anniversary, co-founder Tina Seger talks about living life in the air Tumble Circus begins its 30th anniversary celebrations W eekend is watching Tina Segner twist in complicated turns high up from the ground in her studio. The co-founder of Tumble Circus is not the only one able to demonstrate skills: son Kasper nimbly climbs on top of his mum’s shoulders at another moment, later swinging with her on the silk..