It just seems there are now 2 instances of it leading to concussion (well in the K.O. instance there would have been concern of concussion), I would have previously thought the only way to get concussion in kendo is if you get knocked on your back and smack your head. I would never thought there was a way you could pop someones men that would cause something like that, and am now wondering if there is something specific I should be looking to warn beginners about for safety.