Mixed martial arts is a complex sport. By its very nature, it pulls its fanbase from a wide variety of backgrounds, ranging from jiu-jitsu enthusiasts to wrestling die-hards to boxing and kickboxing connoisseurs. Even if you happen to fall into that last category, however, the precise mechanics of punching, kicking, kneeing, and elbowing might not be clear to you. MMA commentators are generally too busy, you know, commentating, to explain the basics of weight transfer and hip turnover mid-fight. Even if you train Muay Thai or boxing or seek out expert analysis on the topic, not all coaches and analysts are particularly interested in talking at length about the foundational principles of striking, preferring to discuss execution or advanced combination work.
With all of this in mind, I'm going to focus on the essentials here. How do you generate force with a punch, kick, or knee? In other words, what are the basic physical components of a strike? Given the fluidity and speed with which top fighters throw, it's easy to forget that each individual strike is an exceptionally complex combination of interconnected movements, and that's what we're going to explore here.
DISCLAIMER: I'm not saying that there's only one right way to throw a strike, and that everything else is wrong. Every variation on a punch or kick has its positives and negatives: for example, you might take some power off the strike to maximize defense, or sacrifice defense while maximizing power. They're both valid approaches, and truly great strikers can move between them depending on the specific situation. Additionally, I'm not concerned here with angles, movement, or anything else that falls into the strategic/tactical realm, only the basic mechanics.
Let's start with punches.
Punching for Power
There's a tendency to see power as a natural talent, and there are certainly innate physical talents that allow some fighters to throw harder than others. To paraphrase the great heavyweight boxer Jack Dempsey, however, real punchers aren't born, they're made. How? By learning to put the puncher's entire bodyweight behind the strike, making the legs, abdomen, back, shoulders, and arms work together in a single smooth motion. In other words, you're linking the larger and more powerful muscle groups of your legs and core to the smaller muscles of the upper torso. When you hear a commentator talking about "arm punches," they're saying that the striker isn't getting his legs and core behind the blow.
Let's stick with Dempsey for a minute here. His book Championship Fighting, published almost 70 years ago, is still one of the best and clearest explanations of the mechanics of punching that you'll ever read. He divides a well-struck power punch into four steps: first, a hard, falling step forward; second, the weight transfer from leg to leg; third, the whip of the shoulders and core, turning the hip over into the punch; and finally, an upward surge to complete the weight transfer.
We're going to focus here on the most basic and universally applicable portions of this motion, weight transfer and hip turn. If you're throwing a right hand, for example, your weight begins on your back leg and ends on your front as you rotate your hips and step into the strike. You'll occasionally hear a commentator mention a fighter "reaching with his punches": what he's really saying is that the fighter's feet aren't under him while he's throwing because he isn't stepping forward and transferring weight into his strikes,
Punching with the step, weight transfer, and hip turn is a lot harder than it sounds. Give it a try: find some open space and then step forward, rotating your hips as you throw left and right in a slow, methodical sequence. It takes thousands upon thousands of repetitions for this to come naturally.
Watch this GIF of Dempsey in action a couple of times. First, look at his feet and the way he springs forward into his strikes. After you've grasped what his legs are doing, watch his hips and shoulders and the way he rotates them into each punch.
Now do the same with this GIF of Mike Tyson. First, watch his feet, and then his hips and shoulders.
I chose to use these two all-time great power punchers as examples because the mechanics behind the strikes are so clear. In fact, the emphasis on power exaggerates those motions to the point that it's almost comical: Tyson, for example, leaps forward into his punches like he's shot out of a cannon.
Most of the time, however, those mechanics are much more subtle. Watch Dutch kickboxing great Andy Souwer's feet as he works the pads here:
The stepping motion and weight transfer are far harder to detect here, but they're still integral parts of the strike.
Gaethje's footwork here isn't perfect, but you can clearly see his grasp of the basic principles. First, he steps forward into each punch, ensuring that his feet are under him as he throws. Second, he gets his legs and core into the punch, whipping his shoulders and turning his hips. While we're on the topic, Dan Henderson is a good example of a guy who might not be the world's most technical striker, but he's certainly someone who understands the functions of weight transfer and hip turn.
We've looked only at aggressive and stationary punching here, but the same mechanical principles apply to punching on the retreat: you still have to keep your feet under you by stepping as you strike and you still have to turn the hip over. The only real difference is the direction you're moving.
(I was going to include a section on elbows, but the mechanics of the strike aren't much different than a punch: same deal with stepping, rotating the hips and shoulders, and so on.)
We're going to focus here on the basic Thai-style round kick, one of the staples of MMA striking. It's actually a very simple motion, but it takes a ridiculous amount of practice to execute it in the devastating fashion of Jose Aldo, Edson Barboza, or Shogun Rua.
There are three basic components to a round kick, all executed more-or-less simultaneously: first, the step/pivot, which turns the lead foot perpendicular to the target; second, the hip thrust, with the hip leading the kicking leg in the movement; and finally, the hip turn, rotating the hip over to provide maximum force for the kick. The discerning kicker might add a fourth movement, scrunching the abdomen forward into the target to further tie the muscles of the core into the strike, but this is mostly emphasized by Dutch stylists and isn't strictly necessary to the basic function of the strike. There are enough differing schools of thought about hand positioning and arm motion during the round kick that it's safe to say that we don't have to count them as essential components, either.
Note that the kick should land with the hard bone of the shin, not the foot: there's so much force behind the blow that it's easy to break the small bones of the foot if you happen to impact the point of the knee or elbow.
Thai-style kicks are often described as "whipping", without the "snap" characteristic of karate-style kicks. This is only partially true, as the master of low kicking, Ernesto Hoost, demonstrates in this GIF. Note that his leg is partially bent at the knee, and he snaps through the target just as it impacts the target leg.
Here we see the step and pivot, the hip thrust (with the hip leading the kicking leg), the full hip turn, the scrunching of the abdominal muscles, and the snap just as the kick lands.
Here's Thai legend Buakaw throwing low kicks in sequence. Note that he steps hard into the first three, while in the last (because of the range) he simply pivots on his lead leg:
The motion of the strike differs little whether the kick is targeted at the legs, body, or head, as you can see in this GIF of Giorgio Petrosyan:
There's nothing exceptionally complex about the basic mechanics of Thai-style round kick. What's difficult is getting each individual component to work in concert with the others so that the full force of the blow arrives all at once, in a single fluid motion.
Knee strikes, like round kicks, are easy to learn and very difficult to master. Based on my own anecdotal experience, there are some minor variations in technique between the Brazilian style of Muay Thai and Dutch kickboxing, largely due to differences in posture and stance: the Brazilian version tends to emphasize a more upward arc, while the Dutch version employs more of a thrusting motion.
In either case, however, the basic components of the strike are similar. First, the back arches, thrusting the hips forward, much like a thip or front kick; second, the hips turn into the blow, much like a round kick; and third, the knee arcs upward. As with the round kick, all three of these components should happen simultaneously.
Here's Rob McCullough demonstrating on a heavy bag. Note the prominent forward thrusting motion and the turn of his hip:
And here's Duke Roufus demonstrating a full stepping knee with less pronounced thrusting motion and more of an upward arc:
And now let's take a look at one of my favorite MMA prospects, Brazilian Muay Thai specialist Sheymon Moraes, to see a sequence of beautifully-executed knees from the clinch:
As with round kicks, there's nothing too complex about the mechanics of the strike itself. It's getting those different components to work in concert that's hard.
This brings us to the end. I hope this was helpful; if you have any questions or critiques, sound off in the comments or hit me up on Twitter @Patrick_Wyman.