The Americana, or "Americana Lock," is a submission tactic used in Brazilian jiu-jitsu whereby the practitioner of the move takes control of his/her opponent's arm and putting it in an "L" shape, making the elbow and shoulder joints vulnerable. It can also be referred to at the "top shoulder lock," "figure-four armlock," "bent armlock," "keylock," "V1 armlock," the "paintbrush," or the "ude-garami."
Here is a brief look at the history of the move, and how to best use it in combat:
There is no telling when exactly the move was first founded, but what we do know is that it was already around by the 1950s and '60s, fitting into the jiu-jitsu curriculum. Similar to the "Kimura lock," the Americana is thought to have originated from judo and/or catch wrestling. It's possible that the move was introduced to Brazilians when foreign catch wrestlers and Japanese judokas came through the country on pro wrestling tours.
Some of the touring wrestlers were American, and so it is thought that the term "Americana" spawned from the introduction of the move by these Americans.
What the move looks like
The Americana lock is usually performed when one opponent uses his/her opposite-side hand to pin their opponent's arm to the ground. If done correctly, the elbow and the arm will form a 90-degree angle, with the palm facing upwards. At this point, the practitioner of the move threads his other arm through the gap created under the bicep and grabs his own wrist. This sets up what is known as the "figure-four" position.
Now, the practitioner uses his other hand to grab the wrist of the opponent and slide it down towards the lower body, while at the same time elevating the elbow. This puts an enormous amount of stress on the elbow and shoulder joints, causing extreme pain to the victim.
How to execute the move
First things first, you have to be in a dominant position to begin with to perform the move. Ideally, you would be in side-control or in a mount position. As they say in BJJ, "position before submission." Should you fail to launch this attack from a strong standing, you could end up on the receiving end of a counter-attack.
Stay stable on top of your opponent, and if you can, keep his/her elbow as close to their body as possible. This will greatly enhance the torque and power of your move while keeping them in a compromised position.
Stay safe when performing the Americana
Though it is one of the first moves you learn in BJJ, the Americana still carries with it great danger to the recipient of the move. Because of the nature of the lock, and the stress it puts on the joints in the arm, it can very easily lead to a broken arm if you aren't careful.
As the executor of the move, be cognizant of the fact you could break their arm at any moment and, more importantly, as the recipient recognize that you are in a helpless position and tap before it's too late.