Doctor’s Notes: Liver Shots & KOs

Written by: Dr. Jassin Jouria

UFC 141 turned out to be a great event to cap off the end of 2011. The event also provided the opportunity to recap some of the medical science that was displayed throughout a couple of the fights.

1. Liver shots are exceptionally effective yet underutilized in MMA

In UFC 141’s main event, Brock Lesnar was hit in the liver by a left kick from Alistair Overeem. Now, if you have ever been hit in the liver you won’t have to read the following description. For those fortunate people who haven’t, being hit in the liver results in a delayed somatic reaction, where after the pain of the initial impact subsides, the rest of the body feels as if it is shutting down. Completely different from a blow to the head, a liver hit conveys no dizziness, throbbing, or ringing; instead, it produces an eerie sensation where your mind is in complete control and recognizes that you are hurt, but for a few seconds it cannot tell your body to do anything, and you have difficulty breathing. This is mainly due to the visceral innervation of the liver and the location of the hepatic plexus and its close proximity to the right phrenic nerve, which (with the left phrenic nerve) innervates the diaphragm. Alistair Overeem capitalized on this and finished a rather defenseless Brock Lesnar as referee Mario Yamasaki called the bout to an end.

2. Fitch vs Hendricks: The science behind the flash-KO

The second big shock of the night happened when Johny Hendricks knocked out what many people believe to be the number two welterweight in the world, the always tough Jon Fitch, with a heavy left hook to the chin. Contrary to what Joe Rogan says about a nerve in the back of the jaw causes you to go to sleep when it gets hit, the science behind a knockout is a little more complex (sorry Joe). While many studies have been observed documenting the cause of the effects of head trauma from combat sports, most of the studies have reported on the chronic cumulative effects that have resulted in conditions such as pugilistic dementia. However, it is my professional opinion that a knockout results from the acute overstimulation of the sensory nerves that lead to the brain. The central nervous system receives all of the peripheral sensory inputs and processes them in the brain through a series of chemical and electrical signals. This overload, if you will, is analogous to plugging in one too many electrical components into an electrical outlet, delivering in a higher energy input than the circuit can handle – resulting in a shutdown of the circuitry. That one big left hook produced a massive force that Jon Fitch’s brain could just not process properly. The reason some people have a “good chin” is of multiple factors that all result in the same mechanism, a way to “transform” the receiving force into a level that can be processed by the individual’s central nervous system. Such factors include the ability to “roll with a punch” so the force is spread out, having strong sternocleidomastoid muscles that can cushion the force, and having a higher threshold for processing sensorial input–which appears to diminish with each successive knockout (however, this needs to be investigated further).

Fighting is an art, but you cannot disregard the science behind it as well. The most complete fighter understands that the human body is an amazing and dynamic machine, both strong and weak at the same time, with both the capability to overcome almost any obstacle and the vulnerability to succumb to defeat. Such is the beauty of the human being.