Chambering refers to the process of drawing the knee back in preparation to deliver a kick. The term comes from chambering of a firearm, which is when the gun is cocked to feed a round into the chamber so it's ready to fire.
The primary reason for chambering has to do with direction of force. A specific vector may require bringing the striking surface in line with the target. So for example, a side kick delivers force in a linear fashion, so the heel must first be raised to the height of the desired target. Moving straight to the target from where the foot is planted would change the direction of force, possibly reducing it. When considering the anatomy of a kick, it is essential to note that more momentum is created over longer distances. As such, some kicks require chambering in order to maximize the power delivered. Another element to this is that chambering allows one to utilize larger muscle groups to provide more power. For example, a Muay Thai round kick without the chamber would be utilizing the hip flexor muscles, which are considerably smaller and weaker than the quadriceps.
Chambering a kick also adds an extra motion to the technique, so sometimes a requirement of speed over power necessitates removing the chambering motion.
Viam Chao ApproachEdit
In Viam Chao, both chambered an unchambered kicks are taught, as they both have their specific uses. To understand why an unchambered kick may be recommended it is important to understand one of the key benefits of punches. Punches can be thrown from any angle, and without "cocking" them back to execute them. This makes them faster and more agile. The same concept can apply to kicks with the right practice and approach.