Joints affect each other when in motion, and creating “closed circuits” with your limbs makes them stronger.
Kinetic chains are a concept originating from mechanical engineering, but are also applicable to physiology and sports training. From Physiopedia:
“The concept was introduced by Franz Reuleaux, a mechanical engineer, in 1875. He proposed that rigid, overlapping segments were connected via joints and this created a system whereby movement at one joint produced or affected movement at another joint in the kinetic link.”Kinetic Chain – Physiopedia
In Jiu-Jitsu, kinetic chains are important to understand because they dictate how joints will respond when pressure is applied.
Kinetic chains can be either open or closed. In Jiu-Jitsu, we generally prefer closed kinetic chains.
Open kinetic chains:
A kinetic chain is open if the distal segment of a limb (meaning the hand or foot) can move freely. Waving your hand is an example of an open kinetic chain.
Examples of open kinetic chains include:
- Waving your hand
- Swinging your leg with the foot in the air.
Open kinetic chains have application in other athletic endeavours, but not so much in Jiu-Jitsu.
Closed kinetic chains:
A kinetic chain is closed when the distal segment of a limb (meaning the hand or foot) is connected to something and can’t move freely. This “something” could be the floor, your opponent, or another part of your own body.
When you connect your limbs together, you create a “closed circuit” that makes for stronger frames and greater force generation.
When you’re on the defense, closed kinetic chains make your frames stronger. It’s harder for your opponent to break your frames or isolate your limbs when your hands or feet are connected to something.
When you’re on the offense, a closed kinetic chain helps you control your opponent’s body by enclosing a barrier around them. For example, bodylocks or the closed guard require you to establish a closed kinetic chain around your opponent.
Examples of closed kinetic chains include:
- Connecting your arms when framing from bottom side control
- Crossing your ankles when holding your opponent in closed guard
- Defending the Kimura by grabbing your gi
- Defending the armbar by clasping your hands
- Connecting your hands when applying a guillotine.