Could these spikes pop out and accidentally impale a performer if they were to fall from this stage? Actually, this is the Theatre of Kà by Cirque du Soleil. It has a hydraulically controlled floating stage where performers do acrobatics on a nearly vertical plane. The stage has these retractable spikes that serve as handholds, but they start to retract from the bottom as the acrobats race to the top. Once retracted, they won’t extend again until the stage is confirmed clear by multiple sensors and manual checks.
