Roman Kremianski wrote:
Just why exactly would grab you from behind by the shoulders or wrists? (e.g Ushiro Tekubitori).
To hold you still while someone in front of you beat the living crap out of you. A rear barehug would work well for that, too.
One way I think of it is you're not so much worried about the grab itself as what comes after that. (The kata dori-<striking> combinations are for when you're too late.) You deal with the grab to forestall whatever would follow. (Although I also think the grabs are used first to make life easier for beginners, especially given how much longhair stuff there is in Aikido or any other internal art.)
Also, someone trying to sucker punch you from behind will grab you. This happened within the last year or two during a hockey game -- one player came up behind another one, grabed his collar with one hand, and hit the guy in the head. The player who'd been hit fell forward on the ice while still moving forward
and his neck was very badly damaged, enough to end his career. It could have ended his life. And yes, that rear collar grab is also in Aikido, though I blank on the name at the moment.
So tell your dad attacks from the rear are serious business. Individuals intent on doing you in may not square off in front of you, especailly if he has a buddy who can hold you from behind.
I've seen more realistic grabs such as Kakaedori online, but for some reason my dojo doesn't practise them. (Atleast not during the duration I've spent there)
If your dojo covers them, they might be considered advanced technique. Ushiro kubijime, where one hand grabs a wrist and the other goes for the throat, is also more "realistic," but maybe beginners don't see that just to make life easier for them. So don't worry if you haven't seen them.