Improving kick power/strength

[jobo]

That's valid, though it depends what point of the technique you're looking at. F=MA is appropriate if we're talking about the moment of impact, where A is the result of the speed of the attacking limb and the give of the attacked surface.

no you are miss applying it, we are talking about newtons laws of motion, which don't lend themselves to being explained in forum posts, so here is some reading
Force - Wikipedia

in,short, force is the effect an interaction has on the objects involved, so at its simplest, lets take the kicking of a football.

kinetic energy is what you are using to strike it, force is what happens to the football, it has constant mass, so the key point is the acceleration of the object you have hit, not the speed of your foot in hitting it. So you would take the weight of the football and times that by its rate of acceleration to find the force you have generated. If you miss kick and skim the ball. The kinetic energy and speed of your foot is the same, but the force generated in the football is considerably less
if you have made an error in judgement, and kicked a ball made of stone, it won't move, so the force applied os the weight of the stone ball times the deceleration of your foot.

all forces being equal and opposite you will break your foot

so... To measure force you measure the effect on the objects being contacted Not the speed or mass of the body striking the object .

 

[Gerry Seymour]

no you are miss applying it, we are talking about newtons laws of motion, which don't lend themselves to being explained in forum posts, so here is some reading
Force - Wikipedia

in,short, force is the effect an interaction has on the objects involved, so at its simplest, lets take the kicking of a football.

kinetic energy is what you are using to strike it, force is what happens to the football, it has constant mass, so the key point is the acceleration of the object you have hit, not the speed of your foot in hitting it. So you would take the weight of the football and times that by its rate of acceleration to find the force you have generated. If you miss kick and skim the ball. The kinetic energy and speed of your foot is the same, but the force generated in the football is considerably less
if you have made an error in judgement, and kicked a ball made of stone, it won't move, so the force applied os the weight of the stone ball times the deceleration of your foot.

all forces being equal and opposite you will break your foot

so... To measure force you measure the effect on the objects being contacted Not the speed or mass of the body striking the object .

Actually, no. Some of the force is absorbed in the deflection of the football. So there are two different places force can be measured. If you measure the movement of the football, you're measuring the resulting force (to simplify it, this is the force not absorbed by the football in deflection, plus the rebound force from that deflection). The force imparted to the football can also be calculated, and that will be the mass of the impacting object, times that object's velocity change over the time of its contact with the ball. This is harder to measure on a football kick because the foot doesn't stop. If we measured the force of kicking a Thai heavy bag, the foot does stop, so if we measured how long it took to stop (the time the bag is deflecting), we would be able to calculate the force delivered.

The two (force at impact and kinetic energy just before impact) are actually opposite sides of the same math. Neither depends upon what is being struck. The force coming out the other side, however (measured as you suggested), shows the force lost in the object.

 

[marques]

There's a lot of truth in that, Marques. Even using the moment of impact and applying F=MA, you're still left (normally) with more than one force vector to calculate. And if a block is involved, there's a transfer of force through the blocking limb, and that's just a nightmare to even imagine the vectors and calculations.

I think most folks mention the formulae to communicate the concept. For instance, in discussing F=MA, we get to discuss the combination of speed (as a component of A) and getting more than the weight of the limb into the strike (as M).

The same would be true of the kinetic energy formula Jobo cited, which uses most of the same components. Neither will fully describe the damage (that's beyond a mere force/energy transferral), but they help some folks understand why focusing on one area doesn't generate the power they want.

Yep. It can be found again and again high school physics, where the concept was explained with an oversimplified situation, 'applied' to the real world and highly complex systems (as human bodies hitting each other). Sometimes it works, sometimes don't...

For instance, Force (even a huge one) can be 'just' pushing (ex: lifting 300 kg). In striking generally we don't want to push, we want to cause damage or, at least, pain.

 

[jobo]

Actually, no. Some of the force is absorbed in the deflection of the football. So there are two different places force can be measured. If you measure the movement of the football, you're measuring the resulting force (to simplify it, this is the force not absorbed by the football in deflection, plus the rebound force from that deflection). The force imparted to the football can also be calculated, and that will be the mass of the impacting object, times that object's velocity change over the time of its contact with the ball. This is harder to measure on a football kick because the foot doesn't stop. If we measured the force of kicking a Thai heavy bag, the foot does stop, so if we measured how long it took to stop (the time the bag is deflecting), we would be able to calculate the force delivered.

The two (force at impact and kinetic energy just before impact) are actually opposite sides of the same math. Neither depends upon what is being struck. The force coming out the other side, however (measured as you suggested), shows the force lost in the object.

so after a long post, you are now accepting your original post was inaccurate ! You measure force by the acceleration of the football not the acceleration of the foot kicking it.
what your describing in the distortion of the foot ball is a loss between the kinetic energy of the kick and the force received,
but that's irrelevant to this discussion are we are talking about how force is measured, not the efficiency of the contact

 

[Headhunter]

Best way to get good kicks is to practice kicks

 

[Buka]

A person could expound thermodynamics to me in a conversation about cooking, but it probably wouldn't help with the preparing of fine food.

And it sure as hell wouldn't help with the enjoyment of eating a great meal. Martial Artists should eat better.

 

[jobo]

A person could expound thermodynamics to me in a conversation about cooking, but it probably wouldn't help with the preparing of fine food.

And it sure as hell wouldn't help with the enjoyment of eating a great meal. Martial Artists should eat better.

thermodynamics is very important to cooking, image ne f they stated to make up their r own defintions of how to heat something up. They say boil and what they mean is,simmer, absolutely crucial to fine food, that people stick to the accepted defintions

 

[Touch Of Death]

Best way to get good kicks is to practice kicks

Lies! You could practice your whole life, and not know the basics.

 

[Gerry Seymour]

A person could expound thermodynamics to me in a conversation about cooking, but it probably wouldn't help with the preparing of fine food.

And it sure as hell wouldn't help with the enjoyment of eating a great meal. Martial Artists should eat better.

My wife (Master's degree in Mechanical Engineering) and I have had many a discussion of thermodynamics over a great meal. That discussion certainly added to the enjoyment. Of course, she's prettier than you are.

 

[Balrog]

Hey all,

I'm a female who's just got back into TKD.

When kicking the strike shield during class, my kicks feel so weak (especially in the front kick). My partner will usually tell me to kick them harder but I actually can't do it any more powerful - which I hate!

All in all, I actually have very very strong legs but when it comes to kicking it's quite wimpy.

I'm going to buy a padded strike shield to use at home but are there any specific exercises which are great for increasing kick power (with focus on the front kick)? And any exercises that I could do in the gym?

Thanks

Latecomer to the thread. I agree that technique is the key. Here's a drill that you can do to strengthen your legs as well as improve your technique. My students call this the Wall of Pain^G^G^G^GFun drill.

This is excellent for side kicks, hook kicks, etc. Brace against a wall or a bag at arms length with the non-kicking side hand. Put the kicking side hand up in guard. Make sure your base foot is pivoted correctly with the toes pointed at the wall or bag.

Visualize a table in front of you with the edge just below your hip joint. There's a ball on the table. If you bring your leg straight up, you'll clip the bottom edge of the table - not good. Chamber your side kick, pulling the knee back toward the back shoulder. If it's done correctly, you'll look kinda like a doggie on a fire hydrant. S-L-O-W-L-Y extend the leg into the full kick, clearing the edge of the table and pushing the ball off. Hold it locked out for 5-7 seconds, then slowly rechamber it. Lather, rinse, repeat. Do about 4-5 on each leg to start and slowly work your way up to 10 each leg.

Your hip flexor muscles will promptly start screaming at you, because they don't normally get exercised like this and they're weak. As they strengthen, it will hurt less and you will find that your balance is better, your kicks are smoother and they will be stronger because the muscles are acting in the way you want them to.

 

[Swagmaster2993]

You're probably going to get a 1,001 replies and most likely 1,000 different answers but I would have to say that it really comes down to technique more than strength any day.

I have seen so many students that do NOT have great leg strength but still have great power in their kicks. It's all about generating the force (not Star Wars force!) but the F=ma force. Speed and technique beats brute strength every day in my experience.

So, bottom line, develop the technique and hone the technique and the power will come.

This I agree with. But if I may add to it, practice. I know this is a 5 year olds recommendation but it applies to all of us.

 

[PhotonGuy]

the weakness' is in the nervous system, its about teaching the mucles to fire at the right time ,in the right sequence and activate the correct muscle fibres, to develop the power you want, allowing that you have reasonably developed muscles in the first place.

practise practise and a bit more practise. But not endless kicking of a bag,which will only work the slow twitch muscle fibres, focus on single kicks with power that work the fast twitch fibres,kicking a soccer ball may well help as will box jumping

I must say I agree with you about focusing on single kicks with power as opposed to many many kicks on a bag. As you said doing the many many kicks will mostly just work the slow twitch fibers and it might build up your endurance but won't do much to develop speed and power. Instead I would say do ten kicks on the bag and focus on making them explosive. Fast and powerful. Then take a bit of a rest and do another ten fast and explosive kicks. Do maybe ten sets of this for a total of 100 kicks.

I used to do thousands of kicks in a single workout but not so much anymore. Even with all my experience I am still learning new stuff about how to improve.

As for you ladolcevita you say that you've got a good sidekick but you're rusty with the front kick. Since you've got a good sidekick you might want to focus on that and make it your primary kicking technique and get it as strong and as good as possible. Its better to have a few really good moves instead of many so so moves. If the sidekick works better for you than the front kick you might want to focus more on that and not use the front kick all that much.

 

[PhotonGuy]

Hey guys, thanks a ton for the helpful advice. It's nice to get a bit of education on the dynamics of it too



Very helpful response, thanks!

I have been kicking air a lot simply because I have nothing else so that's not benefiting me. It's mainly for technique/practice though. I've bought a kick shield in order to practice at home but I'll have to buy a BOB or century wavemaster. Does the wavemaster take up a lot of room? (I'm renting with not much space). Are there alternatives?

I've got a BOB. It doesn't take up much space and I find it very useful.

 

[jobo]

I've got a BOB. It doesn't take up much space and I find it very useful.

I've got a tree stump, it takes up a lot of space, but its outside so it doesn't really matter

 

[Monkey Turned Wolf]

I've got a tree stump, it takes up a lot of space, but its outside so it doesn't really matter

I saw your post count and was curious about how you have a third the amount of posts as me, when I've been on this site for two years, and your just shy of 2 months. Then I realized most of your posts are posts like this, and now it makes sense.

 

[PhotonGuy]

Best way to get good kicks is to practice kicks

That's over simplified. When you practice kicks there are many different types of kicking drills you can do. It helps to get into specifics.

 

[PhotonGuy]

I saw your post count and was curious about how you have a third the amount of posts as me, when I've been on this site for two years, and your just shy of 2 months. Then I realized most of your posts are posts like this, and now it makes sense.

Some people just post a lot in a short amount of time.

I know "a lot" isn't good grammar but what the heck.

 

[jobo]

I saw your post count and was curious about how you have a third the amount of posts as me, when I've been on this site for two years, and your just shy of 2 months. Then I realized most of your posts are posts like this, and now it makes sense.

just passing on a useful tip, tree stumps are excellent training,aids for kicking power. However apart from the space issue, they can also take a hundred years or more to obtain. So they may not be practical for every one. But then tree abound in public places so you may be able to use one of these. If tree kicking isn't illegal in your state.check with the sheriff's department

 

[Juany118]

I'm wondering if you're not getting enough mass into the kick. If it's just your leg, it won't be enough. You need some of your bodyweight transferred into the kick, as well.

I was thinking the same thing. You can't simply just put the leg out there with your muscles, you must also use a mechanism to get more of your overall mass behind the kick. One way to do that is to "sink" or "settle" into the kick. It's similar with round kick. You don't simply want to pivot on your planted leg you want to rotate the hip of the kicking leg into the target. Hard to describe but in short you need to get as much of the "M" into the "F" equation as possible.

 

[JR 137]

I was thinking the same thing. You can't simply just put the leg out there with your muscles, you must also use a mechanism to get more of your overall mass behind the kick. One way to do that is to "sink" or "settle" into the kick. It's similar with round kick. You don't simply want to pivot on your planted leg you want to rotate the hip of the kicking leg into the target. Hard to describe but in short you need to get as much of the "M" into the "F" equation as possible.

Absolutely agree. And kicking the air won't teach that effectively. And unless you've got an unlimited number of partners willing to take your best shots, sparring won't truly teach that either.

As I said in my first post here, you've got to hit things hard to learn that effectively. There's really no substitute for a good heavy bag to teach and develop stopping power. Well, maybe cows hanging in a meat locker like Rocky used to hit might be better. And you'll help your butcher tenderize the meat