There's no real reason for it, but when chasing goons in a gymnasium, the Atom decides to use the gymnastic rings. Turns out to be a mistake because they turn off the lights, falls and bangs his head. When he wakes up, he's been tied to the parallel bars, but that's just another opportunity to show off his skills!
Reminds me of a Thai action movie starring Dan Chupong and choreographed by Tony Jaa's people. It's called Born to Fight and it's about these young village athletes who use their gymnastic skills to fight an invading army. It's crazy, but it's really fun and cool. I recommend!