Never maximally extend your leg when Kicking?

[REG]

Hello,

I am a brand new member of this forum, as I have just registered earlier today, thus making this post my very first on this forum. Also, not only have I already read all of Mr. Kurz's articles as well as a lot of the forum posts online, but also I just recently got a copy book of "Stretching Scientifically" recently. After having read both the entire set of his articles, along with reading many of forum posts, and in addition to having actually read the entire book already, I find his information to be very helpful and informative, with a lot of plausible and specific explanations on how to rationally train right for optimal flexibility. Though I have a couple of questions about when you execute a kick. I am actually confused as to whether or not when you do any type of kick, whether it be front kick, side kick, roundhouse kick, hook kick, etc., you are supposed to ever maximally extend the kicking leg. I know that Mr. Kurz explained in both his articles and book not only about doing dynamic leg raises to the side with the knee bent in order to make the knees more stable and protected from injury, but also about how throwing roundhouse kicks to "the air" can most likely cause knee joint problems. However, does this mean to never kick with maximal extension, because don't you need the maximal extension of the kick to get greater power? Also, why in pics of Tom Kurz, does he kick "the air" with full extension of the kicking leg, despite what he said about doing dynamic leg raises to the side with a bent kicking knee? I would really appreciate it if someone could clarify this for me.

[cailifo]

Although the final postures might look similar, a kick and a leg raise are two different actions, with two different paths of motion, and two different purposes.

[REG]

Thank you for responding to me Cailifo. However, I am confused as to what you exactly mean when you say that they are two different actions, with two different paths of motion, and different purposes. I mean, obviously I see that they are not actually the same motions since a leg raise is really a raising uppercut with the leg straight, and a kick is usually a chamber with either a thrust extension or a snapping motion like a front kick, side kick, roundhouse kick and bent-leg chambered hook kick, etc. Nevertheless, dynamic leg raises are supposed to facilitate kicks in a sports-specific manner and the knee is supposed to be slightly bent during leg raises in order not only to protect and stabilize the knee, but also to prevent hyperextension in the kicking leg, right? So, how does your response explain the reason why it's fine for Mr. Kurz's roundhouse kicks to be at maximal extension in the pics and video. I would appreciate it if you enlighten me with your response as soon as you can. Thanks!

[cailifo]

To be clear, my point is that in a leg raise you are working on your joint mobility and dynamic flexibility. So the way you will do it will be different from a kick, which is meant to deliver power through a target.

In stretching, with the side leg raise for instance, it is safest and most effective to have the knee slightly bent. This prevents you from over stretching, becoming ballistic, or hurting your knees, as there is less pull from the lower part of the leg. This means that the muscles from the inside of the knee and up into the groin are being isolated in the stretch, resulting in a better stretch anyway.

Stretching this way gives you the joint mobility and dynamic flexibility you will need in kicking. When kicking though, you need to extend and push your power through the target. So you cannot keep your leg bent and expect to get much power out of it.

At the same time though, bare in mind, "maximal extension" is not "hyper-extension". It's like on a circle, 180 degrees is as straight as you can get. When you go beyond that toward 360 you're actually coming back around. You should think of a kick like that. It is maximally extended for power, but not hyper-extended to where injury may result.

[REG]

I see what you mean now Cailifo, but wouldn't kicking at maximal extension risk the likelihood of hyperextending the joint. I mean I agree that you can't kick with the full power that you expect to get with kick, if you didn't maximally extend your kicking leg, but then why does Mr. Kurz say in his online article column 8 "Another cause of joint problems is kicking 'the air' rather than bags or shields. While kicking the targets, students have better control of the path of the kick, especially its final phase whereas without a solid target joints are often overextended (what you call “snapping out” of the leg to full extension). This is a problem for me, because I practice a martial art called Hapkido which consists of Korean kicks very similar to Taekwondo (in addition to some special low kicking), and our instructors sometimes have us practice our kicks with a shield or a bags, but we more often practice our kicks to "the air" if not with a focus paddle (which doesn't provide really that much resistance). So, What can I do about that? Thanks again.

[cailifo]

I practice and teach martial arts as well. Basically it's about control. I can easily do a fast snapping roundhouse in the air without hyper-extending my knee. At the last moment during the kick the muscle should be tensed which adds to the snap and thus power, and also strengthens the knee, then pulls it back quickly which also prevents it from hyper-extending. I've never had a problem with it. Such a problem would arise if the kicker uncontrollably threw their kick out and didn't have any snap or retraction. If that is happening, then they are either not being taught properly or not paying attention to instruction.

[REG]

I practice and teach martial arts as well. Basically it's about control. I can easily do a fast snapping roundhouse in the air without hyper-extending my knee. At the last moment during the kick the muscle should be tensed which adds to the snap and thus power, and also strengthens the knee...

Oh, so you're saying that at impact, after maximally extending the kicking leg, you should tighten your quad muscles of the kicking leg, right?

... then pulls it back quickly which also prevents it from hyper-extending. I've never had a problem with it. Such a problem would arise if the kicker uncontrollably threw their kick out and didn't have any snap or retraction. If that is happening, then they are either not being taught properly or not paying attention to instruction.

I see what you mean here. By the way, is that why muay thai or kyokushin karate practitioners actually have their kicking knee bent when executing their style of a roundhouse kick, because their roundhouse kicks are very continuous, non-retractable, and less controlled than a Taekwondo-like roundhouse kick? Also, what about when you are kicking with more of a thrust motion and very little to no snapping motion in it for more power (but at the cost of speed)?

...When kicking though, you need to extend and push your power through the target. So you cannot keep your leg bent and expect to get much power out of it.

At the same time though, bare in mind, "maximal extension" is not "hyper-extension". It's like on a circle, 180 degrees is as straight as you can get. When you go beyond that toward 360 you're actually coming back around. You should think of a kick like that. It is maximally extended for power, but not hyper-extended to where injury may result.

I understand what you were saying before about this; however, I actually just realized or remembered earlier as of today, that Mr. Kurz has stated in his punching article, "1. At the end of the punch, your elbow is bent in both the sagittal plane and the transverse plane so your arm and forearm do not form a straight line whether looked at from above or from the side." So why isn't the same thing supposed to happen with the end of a kick?

[cailifo]

Oh, so you're saying that at impact, after maximally extending the kicking leg, you should tighten your quad muscles of the kicking leg, right?

Right.

By the way, is that why muay thai or kyokushin karate practitioners actually have their kicking knee bent when executing their style of a roundhouse kick, because their roundhouse kicks are very continuous, non-retractable, and less controlled than a Taekwondo-like roundhouse kick?

It's what happens when you engage the muscles, which by the way controls the kick. So it is not less controlled, it's simply a different way to deliver power, by twisting at the hip.

Also, what about when you are kicking with more of a thrust motion and very little to no snapping motion in it for more power (but at the cost of speed)?

With a thrusting side kick, for example, it should still be retracted quickly. So it makes like a "pop" at the end of the kick, almost like a snap, although it is still a thrusting kick. That way you are not just leaving your leg out after the kick or dropping it, which is a good way to let the opponent grab it. After you've thrusted out there is no reason not to pull it back just as fast. You just have to know how and when to tense and retract at the end of the kick to avoid hyper-extension.

I understand what you were saying before about this; however, I actually just realized or remembered earlier as of today, that Mr. Kurz has stated in his punching article, "1. At the end of the punch, your elbow is bent in both the sagittal plane and the transverse plane so your arm and forearm do not form a straight line whether looked at from above or from the side." So why isn't the same thing supposed to happen with the end of a kick?

That point at the end of a punch or a kick where you tense the muscles to deliver power is what stops the joint from locking or hyper-extending by becoming too straight. That point, in my style of martial art, is called "straight but not straight, bent but not bent". It is still a maximal extension, but the tensed muscles protect the joint from locking straight or hyper-extending. Hold out a punch with the arm very straight, then tense the whole arm and see what happens around the joint. "Straight but not straight, bent but not bent".

[REG]

It's what happens when you engage the muscles, which by the way controls the kick. So it is not less controlled, it's simply a different way to deliver power, by twisting at the hip.

I understand that, but then how come a muay thai or kyokushin karate practitioners throw a roundhouse kick with the kicking leg bent?

With a thrusting side kick, for example, it should still be retracted quickly. So it makes like a "pop" at the end of the kick, almost like a snap, although it is still a thrusting kick. That way you are not just leaving your leg out after the kick or dropping it, which is a good way to let the opponent grab it. After you've thrusted out there is no reason not to pull it back just as fast. You just have to know how and when to tense and retract at the end of the kick to avoid hyper-extension.

Oh, I actually forget to mention to you before about the way we generate power in our thrust kicks. I don't know if whether or not this particular stylistic quality is exactly the same in your style of martial arts, but when we practice our thrust kicks, usually before retracting the foot along the same path, we have our kicking leg momentarily locked-out as hip and body momentum add force to the strike in order to fully commit our weight and power to the strike. I just wanna make sure that the kind of thrust kick that I precisely use applies to what you just said about retracting quickly regardless of whatever the kick is.

That point at the end of a punch or a kick where you tense the muscles to deliver power is what stops the joint from locking or hyper-extending by becoming too straight. That point, in my style of martial art, is called "straight but not straight, bent but not bent". It is still a maximal extension, but the tensed muscles protect the joint from locking straight or hyper-extending. Hold out a punch with the arm very straight, then tense the whole arm and see what happens around the joint. "Straight but not straight, bent but not bent".

So, after I tense the whole arm (including all my forearm muscles, triceps, and biceps muscles in the punching arm), after making the arm very straight, I should see a very slight bent in the forearm about (1-3 degrees)?

[cailifo]

It's what happens when you engage the muscles, which by the way controls the kick. So it is not less controlled, it's simply a different way to deliver power, by twisting at the hip.

I understand that, but then how come a muay thai or kyokushin karate practitioners throw a roundhouse kick with the kicking leg bent?

That's what I meant. Same as when tensing the arm at the end of a punch, it naturally bends. It's also safer keeping the knee slightly bent when throwing a roundhouse kick that doesn't snap.

I just wanna make sure that the kind of thrust kick that I precisely use applies to what you just said about retracting quickly regardless of whatever the kick is.

I don't know your style, so it's probably best to listen to your instructor. But in general, if you thrust your kick out and hold it there, there's a large chance that it's going to be grabbed. Even if you make contact, while the opponent is being knocked back, they can still grab your leg. So it's always best to make it quick. After thrust out all the way, that's where the power reaches it's maximum. There is no reason to keep it out any longer.

So, after I tense the whole arm (including all my forearm muscles, triceps, and biceps muscles in the punching arm), after making the arm very straight, I should see a very slight bent in the forearm about (1-3 degrees)?

Yes, more or less.

[REG]

REG wrote:

cailifo wrote:
It's what happens when you engage the muscles, which by the way controls the kick. So it is not less controlled, it's simply a different way to deliver power, by twisting at the hip.



I understand that, but then how come a muay thai or kyokushin karate practitioners throw a roundhouse kick with the kicking leg bent?



That's what I meant. Same as when tensing the arm at the end of a punch, it naturally bends. It's also safer keeping the knee slightly bent when throwing a roundhouse kick that doesn't snap.

Oh okay, so then it actually is for both reasons: 1. Muay Thai kicks deliver power in the roundhouse kick entirely through the hips with no snap at all in the lower leg. 2. By having a natural slight bend in the leg after tensing the leg, you protect the knee from hyperextension when throwing a roundhouse kick that doesn't snap yet is more continuous in motion. Right?

[cailifo]

I haven't actually studied Muay Thai, but yes, that's what I see and feel in the technique.

[REG]

Ahhh, now i get. Now it all makes total sense to me. I'll try to keep all this in mind when practicing. Thanks again for your replies, I appreciate it alot!