As a rule, the strongest kicks will be the ones that employ a spin to generate momentum prior to the kick. Spinning generates power by projecting your bodyweight into the kick. The two most powerful kicks are the turning side kick and meia lua de compasso. These two kicks are strong because they both set up with a spin, and use the stronger posterior chain muscles to generate power. Both kicks are capable of a knockout. The turning side kick most often targets the torso to crumple to opponent, while meia lua de compasso aims for the head and a knockout.
Spinning kicks in Mixed Martial Arts
Spinning kicks are somewhat of a novelty in mixed martial arts. Although many martial arts deploy spining kick techniques, MMA has only recently begun seeing these techniques employed at the highest levels of competition.
We can look at outstanding strikers like "Wonderboy" Thomson for effectively spinning kicks that knock out his opponents. Every time Wonderboy lands a spinning kick, you can see that his opponent is either knocked out or severely stunned. Spinning kicks are sometimes seen as a "risky" tactic. However, the risk/reward of nearly knocking out your opponent form a single strike makes the attack understandably tempting.
Best Kick for knockouts - Meia lua de Compasso
Meia lua de Compasso is the kick with the highest likelihood of a knockout if landed. The reason is that all the force of the kick is concentrated into the heel. The heel is much small than a shin or sole of the foot. These are the tools used in roundhouse kicks and push kicks, respectively. The small surface area is why meia lua de compasso is able to produce a ridiculous amount of power.
Meia lua de compasso draws its power from the rotational forces generated by the hands. From the set up, the hands swing down and between the legs creating a lot of torque. This toque coils the body up like a spring and releases that power with the kicking leg.
Meia lua de compasso is difficult to land. The heel is small, and if you are aiming for the head, your target is also small. But, you do not need to land a flush kick to knock someone out. The kick is plenty powerful and even a grazing strike could put someone out.
Spinning heel kicks
Many martial arts have similar kicks that all fall under the category of "spinning heel kick". Unlike the Meia lua de Compasso, a spinning heel kick most often keeps the torso up high or parallel to the ground as the kick is released. Regardless, the kick is very powerful and can easily drop an opponent.
Hardest Hitting Kick - Turning side kick
Side kicks are about shoving your target with so much force that they crumple into a ball. This kick functions similarly to the push kick. The push kick however is much less powerful and is more often used to manage distance.
The turning side kick is with the back leg. You prepare for this kick by swinging the arms around toward the back leg to start generating power. Next chamber the kicking leg and then push the leg forward into your target.
The turning side kick has great power that is meant land on the stomach or chest. Watch below as Joe Rogan teaches the great George St. Pierre how to do a turning side kick.
The Most Efficient Kick - Chapeu de Couro
Another kick that throws the weight of the body into the kick is chapeu de couro. This is another Capoeira kick that launches itself at the opponent's head or ribs. Similar to the other kicks mentioned, chapeu de couro can generate a great deal of force due to the rotation of the kick and the use of the kicker's bodyweight. During a fight science test, chapeu de couro was was proven to be the most "efficient" kick. Meaning that the kick was able to produce the most amount of force given set speed.
The kick starts from a crouched position called negativa or cocorinha (full squat). From there, the Capoeirista brings one hand forward and launches their bodyweight into the kick.
This kick is not as fast as a turning side kick or Meia lua de Compasso, but there is an element of surprise that can be useful in certain situations.
The Most Useful Kick - Roundhouse kick
The roundhouse kick is by far the most useful kick in combat sports. The kick is powerful, fast, and difficult to defend. Just about every martial art that employs kicks uses some form of roundhouse kick. These kicks can be used against the legs, ribs, or head of your opponent. The main advantage of the roundhouse kick is the versatility and speed. A roundhouse kick can target the legs, ribs, and head.
Similar to the turning back kick, the back leg will deliver the strike. The reason this kick is not as powerful as the turning side kick is because it uses the anterior muscles (front of the body) to generate power as opposed to the posterior muscles(back of the body), which are must stronger. Despite not being the strongest kick, you will see this kick much more often because of the variety of use cases.
The most powerful lead-leg kick - Side kick
The standing side kick is by far the strongest stationary kick. By chambering the leg up into the chest, the kicker is able to create a great amount of force. Unlike the spinning kicks we reviewed, a lead-leg side kick does not draw as much power from the upper body. But the kick does use the power posterior chain muscles, which gives a lot of force behind it.
In mixed martial arts, the lead leg is often used similar to how a jab is used in boxing. The kick can be used to measure distance, create space, or provoke the opponent into moving and doing something that would give you an advantage.