Here is the best one arm planche I've ever seen with the arm locked throughout the majority of the hold. It's still not perfect, but this the first time I seen it with the arm locked. Could he be the first one to achieve this skill with locked arm, because every handbalancer I've seen who does this also bends their arm slightly?
I remember Mikael (Handbalancer) say that people bend the arm slightly to not only make it require less strength, but also to make it much easier to balance. Are there any handbalancers who does it with locked arm too?