Achilles Lock

I got to try some ground work with Sensai Robles on tusday night. He hurt his neck and was wearing a t-shirt. This was eye opening as it meant there was no collar on his garment to grab onto. So collar chokes were out. Turns out chokes and strangles are most of my ground work which was an interesting discovery in and of itself and definitely something I need to work on. Since I had nothing to work with on above the wast I kept trying to get Sensai with a figure four ankle lock. Apparently I did a comical job of it because when we were done Sensai though I was trying for the achilles lock. He was giving me the benefit of the doubt – the Achilles Lock is a much better technique to go for from the position I kept working from. 

The Achilles Lock is an ankle lock where the Radius of Nage’s arm is driven into the Achilles tendon of Uke. The technique is shown below from a seated position – but it looks like this technique can also be used from a standing position. 

The figure below shows the bones and muscles of the lower leg. The Achilles tendon connects the calf muscles to the Calcaneus or heal bone. It sits behind the tibia.

Once Nage positions the radius of his forearm on the achilles tendon of Uke, he sets the technique by arching his back away from Uke. The set is similar in this respect to a seated arm bar.  I need to talk to Sensai and ask him to show me ways to setup this technique – I tried this out on two different people at the dojo but just could not get into position to throw the technique. 

The achilles tendon connects to one of the strongest muscle groups in the body. It can apparently take 2-12 times the persons body weight when running or jumping. That stress is translated along the length of the leg. Two common achilles injuries are when the achilles stretches or snaps. Since this technique applies force orthogonally to the tendon I am forced to wonder how likely it is to cause achilles injury when applied. If not a snap – certainly a stressing or strain.