Take a look at one of your limbs and straighten it as much as you can. Notice that your elbows and knees each have a clearly defined limit of rotation – these are called “joint limits”. While you might not think about them much, Brazilian Jiu Jitsu fighters see our joint limits as exploitable weaknesses. Martial artists have been inventing and refining ways to hyperextend their opponents’ joints for hundreds (if not thousands) of years. These “joint submissions” are executed by acting as human levers or torque wrenches, trying to rotate joints past their limits.
Naturally, the best defense against joint submissions is to never allow your opponent the chance to start trying one. However, if you get caught in an inescapable joint submission, you have a few options. Take the arm bar for example:
The attacker traps his opponent’s arm against his chest, applying an upward force on their bicep from the hips and a pulling force with their hands on the wrist. These forces generate a torque on the elbow joint. You can try to resist the torque by contracting your arm muscles, but this counteraction becomes more difficult over time. As your arm is extended, your opponent’s leverage increases while yours decreases. Eventually, your elbow ligaments are the only things bearing that torque. At this point you should submit to your opponent to release that pressure, but what happens if you don’t?
Most people can hyperextend their elbows a couple degrees before any damage is done to the surrounding tissues but as more torque is applied, what ligaments undergo the most stress? A study conducted in 2017 showed that those who experienced injuries from armbars primarily showed damage to the ulnar collateral ligament (UCL) which connects the humerus to the ulna bones. During hyperextension, this ligament is pulled tight like a rope, and under enough stress it snaps.
Now you may be wondering if Jiu Jitsu practitioners have trained their joints to have super-human flexibility, but our ligaments cannot be developed like our muscles can. Studies show that the UCL responds to activity with temporary changes in its mechanical properties, but further research applied to grappling sports in particular is needed. With all that being said, it is safe to say that “tapping out” should not be considered a sign of cowardice, and when your joint is being hyperextended, it is something you should do sooner, rather than later.
Feature image from graciebarralondon.com