what is this move called?

so i was grappling with my training partner, and he had my back, and i was in his guard. he was trying to put a choke on, and i wrapped my legs around his feet, effectively putting his feet in my guard, then squeezed. soon as i did that, he let go, went straight onto his back and tapped like crazy. said it hurt like hell. i was just wondering if it has a name at all. must have been done before right?

here is a pic we took to better explain it. any ideas?

Don't know what it's called but had the same done to me .
Never cross your feet if you take the back,hook them in great advice wish someone had told me
If you found this by yourself well done that's what it's all about
Karl

The pain this gave was quite nasty. Felt like my whole shin was going to split from ankle to knee. Hooking of legs advise taken on board. I'll try not to make the same mistake again.

Rick,

It is a foot-lock, plain and simple. You CAN cross your ankles when you have back mount, BUT do it to the side and not in the middle. It is a cardinal rule in submission grappling for the exact reason given by your experience never to cross your ankles in the middle. However, if you cross your ankles to the side you can then transition to a body triangle, which can be quite sadistic and isolates the upperbody. It puts a lot of pressure on the abdomen and can increase your chances of getting the choke.

thanks Jamie. just goes to show, not everything has to be complicated. it didnt even cross my mind that it could be just a footlock! and thanks also for the extra advice, will come in handy on tuesday when we spar again

If you have someone put a standard footlock on you (leg isolated with foot trapped under the armpit) and then have them repeat the move you described. You will notice that the pressure is in exactly the same place and therefore it is, essentially, the same submission.

Here are some links that mention the body triangle and how to counter it:
https://www.youtube.com/watch?v=HUnYDMXcsKo
https://www.youtube.com/watch?v=3hXSvavwyks&feature=related

I hasten to add the counters being described against this particular hold are not nearly as easy as they look. At least not as straightforward as your counter to the regular mistake of crossing your ankles in the centre of a back mount.