I wondering if any of you have encountered this; if it's normal practice or a quirk of a group or groups.

You present yourself to the judges, give your name and so on and then show that you're unarmed by showing the inside of your right wrist.

From a cultural/histoprical perspective I get this; training in Hojo Jitsu I was taught to hide the kagi up the sleeve with the nawa coiled under the lapel.

The reasons I ask are twofold:

1. It's clearly bollocks. There are far better places about the body to hide weapons, as I note every time I get half-heartedly searched when I go to a concert

2. I see this practice outside of martial arts too and I wonder if one has got it from the other or if it's a case of convergent evolution