how do u do a Super hard Smash. Theres this one guy who can smash so hard and he's just average build :)

Practice your technique

Well, what is involved is several things. Shoulder rotation, arm and elbow trust and the wrist power importantly. They all act as a system, so if you're weak in a certain area that's going to affect the smash. But with practice you should be able to preform your own powerful smash.

My smashes can be powerful but I know my strength is weak for my age. My classmate who's muscular and can perform powerful smash (lending him my racket) a lot more powerful then me since he's got the power and can do a kill shot since he's taller as well.

Matt, these things are importaint to your smash, not everyones. Ask panhandle, I'm sure his is an absolute killer. If you are not strong are you saying that Mark Henry "The Worlds Strongest man" will have the best smash in the game? By the same notion are you implying that the juniors I coach cannot smash since they have very little muscle bulk? Of course they can! I suggest changing your technique so you benefit from what you have rather than trying to build yourself up to what you think you need

It's got nothing to do with muscle, height, strength, the brand of racket you use, the brand of shuttle you use, the way the wind blows, colour of your socks, type of grip etc.

If you can't smash properly you will never get a good smash! There are a few techniques for smashing, the best way to advance is to go and book a hour lesson with a coach. You never know you may not be using the proper technique or in fact the technique that best suits your game.

the power of a smash comes from your upper body (abdominal rotation) and legs. As for wrist and arm, without leg strength and upper body, the smash will not be as strong as one can get it to be with the whole combination.

Originally posted by Dill
Matt, these things are importaint to your smash, not everyones. Ask panhandle, I'm sure his is an absolute killer. If you are not strong are you saying that Mark Henry "The Worlds Strongest man" will have the best smash in the game? By the same notion are you implying that the juniors I coach cannot smash since they have very little muscle bulk? Of course they can! I suggest changing your technique so you benefit from what you have rather than trying to build yourself up to what you think you need

It's got nothing to do with muscle, height, strength, the brand of racket you use, the brand of shuttle you use, the way the wind blows, colour of your socks, type of grip etc.

If you can't smash properly you will never get a good smash! There are a few techniques for smashing, the best way to advance is to go and book a hour lesson with a coach. You never know you may not be using the proper technique or in fact the technique that best suits your game. I give a round of applause to you Dill. That was an excellent reply. :)

most true. I weigh maybe 100 lbs more than our local (Vancouver) BF member, Chi-Ho. His smash is 100 lbs heavier than mine!

He looks like a computer tech-y guy. Me? Entry-level sumo-wrestler. I run off the court if I have to face a half-court smash from him. Sorry ... make that "waddle off the court."

-dave

Originally posted by Dill
It's got nothing to do with muscle, height, strength, the brand of racket you use, the brand of shuttle you use, the way the wind blows, colour of your socks, type of grip etc.


Yah yah but.... Don't exagerate and be realistic.

Technique is probably the most important point but even if you ahve the right technique and no power, you smash will still be weak. Everything is in interelation and I think Dill was right about some factors.

Muscle, height strenght, brand of racquet, type of shuttle, grips (size, type) can all enhance a smash.

Since this thread is in Equipment forum, then I will assume you are asking for hardware requirements for the powerful smashs.

1. Good racket: so you can play :p
2. Strings suit your style: this is crucial because everyone has different preferences.
3. Useable Grips: so you can hold your rackets well without returning the smash along with your racket flying into the opponent face :D
4. Shoes: without a pair of good shoes, you don't smash because you will never get to the right place to proceed it.

That's about the equipments I can think of now. :)

Now that's a fast way to clear the courts:D! I would rather take the bullet smash than having to face the half-decent smash and the accompanying boomerang. Hmm... which one will take my head off first? So hard to decide:D.

Originally posted by bluejeff
3. Useable Grips: so you can hold your rackets well without returning the smash along with your racket flying into the opponent face :D

Originally posted by cappy75
Now that's a fast way to clear the courts:D! I would rather take the bullet smash than having to face the half-decent smash and the accompanying boomerang. Hmm... which one will take my head off first? So hard to decide:D.

Well, at least you know what to do when you are losing the game ;):p

If this is a Technique question.. please move this thread to General.

Originally posted by yonexfanatic
the power of a smash comes from your upper body (abdominal rotation) and legs. As for wrist and arm, without leg strength and upper body, the smash will not be as strong as one can get it to be with the whole combination.

No it doesn't

Are you saying stick or flat smash does not exist then? It uses only the power of the forearm from the 12 O'clock preparation stage to the final execution of the stroke without utilising any other part of the body you would doing what you guys would call a traditional smash. At a push I would even concede the whole arm plays a part but no other.

Originally posted by Brave_Turtle
Yah yah but.... Don't exagerate and be realistic.

Technique is probably the most important point but even if you ahve the right technique and no power, you smash will still be weak. Everything is in interelation and I think Dill was right about some factors.

Muscle, height strenght, brand of racquet, type of shuttle, grips (size, type) can all enhance a smash.

In a smash, Technique IS POWER.

As I put in my original reply, I coach juniors at about age 10 and one of them has a smash that would make a full grown adult cry. So where is the power from a 10 year old?

I think what he's indirectly trying to say is that there is more than one way to get power out of your smashes.

While it's true that Technique is the key to power, that does not mean you can't also have a powerful smash when your technique is poor.

Originally posted by curtis
I think what he's indirectly trying to say is that there is more than one way to get power out of your smashes.

While it's true that Technique is the key to power, that does not mean you can't also have a powerful smash when your technique is poor.

Exactly what I tought

Originally posted by curtis
I think what he's indirectly trying to say is that there is more than one way to get power out of your smashes.

While it's true that Technique is the key to power, that does not mean you can't also have a powerful smash when your technique is poor.

As stated earlier on: I'm sure Panhandles smash is a killer, using the wrong grip is the best way to develop a very powerfull smash since this has developed into what is now known as "stick" or "flat" smash.

People can say anything about how you play and what grip you use but if it works for you, use it.

Just as a final note on this thread, have any of you seen disabled players smashing? If they play in a wheelchair how then do they use the legs and hip rotation? Although it gives you momentum for the proper footwork in a traditional smash it is by no means required, power from the hip is something that has migrated from martial arts and also an emphasis to make people lead with the racket leg at all times. But the problem is we do not all play in a traditional "by the book" manner.

You need to find a technique that suits your game and not always apply the traditional formula.

Dill,

As commendable your opinion on smashing technique is, I cannot agree with the idea that any one player can use an ideosyncratic method and show that it is the best way for him/her to play a smash. Here's why...

IMHO, the perfect smash is one which is hit at the highest point FEASIBLE (not possible, as we have discussed in another thread), hit with supreme power (= force x speed), at the steepest possible angle, and either bissecting the opposition or hitting the outside of an outside tramline. A possible addition would be to use the minimum energy required, but this is a function of "supreme power" and both these items would compromise each other (this is why some disagree about how important power is in a smash). Forget opposition stengths and weaknesses; this smash will NOT be returned, full stop!

When one thinks very carefully about this perfect smash, one draws the conclusion that THE (i.e. definiing and definite) perfect smash goes hand in hand with THE perfect technique. Hence, we should use THE technique which would befit the perfect smash.

1. Steepest angle: achieved by a high, balanced jump and a correctly angled and positioned racquet, in view of the provisional speed of the shuttle. High balanced jump achieved by prepared, correct footwork and powerful push from ground.
2. Supreme power: achieved by a tight grip on contact, a racquet strung to X lbs, and the correct body rotation to generate the maximum head speed possible. To have completely (100%) efficient usable muscles for the smash.

etc...

We should all aspire to be able to play the perfect smash, even though no-one will ever achieve this. We only deviate in our methods because A) we are all deficient in certain areas of the game, and/or B) in truth, no-one knows how to perform the perfect smash (as no-one is yet to have done so).

Dill, my assumption on reading your post is that you believe in both A) and B), yet at any level we can't simply advise players to use a technique which makes life easy for them; this only disregards their bad habits. You said so yourself - technique IS POWER, so surely we should all be familiar with the best known technique instead of working with what we are used to?


Ttktom:

In answer to your question, the most powerful smash will require a correct grip (and tightened on contact), and a lot of racquet head speed. The latter isn't so easy to get to grips with or so simple to hone, but I think you can figure out how to do this yourself, and by reading more threads (body kinetics and Mag's revelation are my favourites).

My hint is to think of your body as a system of levers and effort exertors. Think specifically about the timing and direction of the system. Think compactness, efficiency, control. How will this system work most effectively? I eagerly await your response.

Links to those posts: Body kinteics for power strokes (http://www.badmintonforum.com/vb/showthread.php?s=&threadid=11173&highlight=body+kinetics) / A revelation (http://www.badmintonforum.com/vb/showthread.php?s=&threadid=11109&highlight=elbow+high)

Aleik.

Well definately there are too many notions and variabvle which can affect the smash. Drill is also right too.

No actually Aleik, the point I'm trying to get across is that there are many different ways to smash.

That is not and cannot be debated, I myself smash three different ways in the normal course of a game. In other words I know how to get the benefits of three different ways of smashing.

When I coach I give options to my players. If I can smash different ways then I will give my players more options than I have so they can out play the opponent.

You make assumptions based on what you regard as the optimum smash but others can and will disagree, myself being one of them.

Because we all have different games and different styles the smash (as with all strokes) has to be adaptive to each individuals playing style. You are being to idealistic thinking a smash has to go down fast and hard. In baseball this is called a changeup when a pitch suddenly goes super fast. Not all smashes are fast and at the same angle hence Matt noticing the main consideration - VARIABLES.

Isealism is all very good if we were all automitons but we are as individualistic as snowflakes. Ask several good coaches to tell you how to smash, they will more than likley tell you the same way but watch them smashing and they will no doubt execute the stroke differently depending where they are on court.

And as a passing thought, In your opinion what is the correct grip for a smash?

What are some important attributes of a good smash?

It's doesn't matter what manner the good smash comes in. There's only one quality that matters... when it gets you a point. If it's out of bound or returned, it's not good enough.

Originally posted by SchrodingerCat
What are some important attributes of a good smash?

Originally posted by Dill
In baseball this is called a changeup when a pitch suddenly goes super fast.

Actually, a change-up is a relatively slow pitch. To the hitter, it's supposed to look like a fastball is coming, but the slower speed causes the hitter to swing too early. The badminton equivalent would be something like a 3/4-speed or half-smash.

Which brings up another point about the smash: in the course of a game, not all smashes have to be hit at full speed. Varying the speed can throw the defender's timing off and cause an error, or at least a weaker shot than the defender would have made if he got it at the speed he anticipated.

or a smash with a lot of spin. the impact will sound the same. the birdie will be initially fast. however, as the shuttle decelerates, the air resistance from the spin takes over and suddenly slows down the birdie.

Heh! I do that w/o knowing how... usually a flattish crosscourt smash that goes loud and fast but somehow made it near the baseline:D. Basically a sliced smash that has enough power to look like a smash but ends up being an offensive clear. Hadn't done that in a long time, but it occasionally crops up:o.

Originally posted by kwun
or a smash with a lot of spin. the impact will sound the same. the birdie will be initially fast. however, as the shuttle decelerates, the air resistance from the spin takes over and suddenly slows down the birdie.

Oh, I see now Dill. Although my own approach is to work towards an unreturnable smash, I know how important it is (for some) to take into account the variables. I just prefer my smash to be continuous...consistent...relentless. ;)

Aleik.

Like Chandra W.

Originally posted by Aleik
Oh, I see now Dill. Although my own approach is to work towards an unreturnable smash, I know how important it is (for some) to take into account the variables. I just prefer my smash to be continuous...consistent...relentless. ;)

Aleik.

Don't forget the footwork required to get you into position behind the shuttle.

Originally posted by Pete LSD
Like Chandra W.

I wish!:D

Thank you for all your replys they have been most helpful :)

i mean my smash is quite hard but i don't think it's quite hard enough :) I think i do need to work on my technique.

Get a head-heavy racquet like the Armortech500 or 700. My smashes are improved a lot because of the head-heavy racquet.

Unfortunatley i can't return as fast. I'm the master of "ping-pong", you know those quick drives back and forth over the net at the service line. Man, i love those.

not always the case Justin123

The choice of racket makes very little difference to your playing ability. It is true that, as you progress, buying a better racket becomes worthwhile. However, it will only make a minor difference.

Why do people often look to equipment to improve their ability? The answer is simple: buying a racket is easy; training is difficult. If you want to get better then train better:

[list=a]
Train your fitness and strength
Train your shot technique
Train your footwork
Train your tactical awareness
[/list=a]
To an extent, you can train by just playing games. But the best way is to perform more dedicated activities: fitness exercises and skills practice sessions.

That said, there is some equipment that is VERY important. But unlike a shiny new high-tech racket, it is not at all "glamourous". The most important equipment you can buy is:

[list=a]
Grips: you must make sure that your racket handle is the correct size. If it is too small OR too large, you will be forced to hold the racket tightly rather than loosely. Use grips to increase the size of the handle to a comfortable level.
Shoes: get some decent badminton shoes to support your feet. Don't play badminton in your scummy old trainers. Replace your shoes directly they start to loose support.
Socks: wear thick sports socks ("Thorlos" are good) to cushion your feet and prevent sore callouses from forming.
[/list=a]

Originally posted by ttktom
i mean my smash is quite hard but i don't think it's quite hard enough :) I think i do need to work on my technique.

Perhaps in conjunction to produce super hard smash (as you first asked), you might think on utilizing effective smash tactic (ie steepness (close to the front or close to the baseline), way from your opponent, at your opponent, etc) such that your opponent has a hard time returning or a weak return is produce that you can put away easily.

Cheers. :)

Perhaps you should do it this way... (random pic from Swiss Open website, www.swissopen.com).

See how the body is rotating, transfer of energy from the legs and ends all at the point of the racquet, all concentrated towards the shuttle head. And to hit the shuttle when you are just, only just, beginning to drop down from your jump.

ps - I myself had been trying to master all that for months... keep trying...

Sorry, didn't attach the thing..

One question: Is he jumping forwards, sideways or backwards? In the middle of a game, it is not very often that we will get the chance to move quicker than the shuttle to execute this kind of smash by jumping forwards, as told by experts. I've seen more sideways and backwards jumps than forwards during the past one year.

Originally posted by Dill
It's got nothing to do with... height...
Height plays a very important part in smash power. Short people can't hit as hard as taller people simply because their lever for hitting is going to be smaller.

Disclaimer: This does not mean that all short people smash slower than all taller people, but unless their technique is well tuned, this is often the case.

Phil

I agree, it's just harder for shorter people to smash because they may be forced to jump.

Imagine a person that is shorter than 5'.......a jump shot is a must.....and it's going to be hard.:)

I don't think there are any players of mention, that are 5 foot or under. All their rear court smashes are virtually drives, but they do have the upper hand in these mid and low shots.

Height plays a very important part in smash power. Short people can't hit as hard as taller people simply because their lever for hitting is going to be smaller.

Disclaimer: This does not mean that all short people smash slower than all taller people, but unless their technique is well tuned, this is often the case.

Phil


well Theres a Woman in Division 1 she's only 5ft and she's got one hell of a smash on here she can beat some of the men in her own team

Like most people said... perfect your technique, and work on some strength building exercises.

height indeed play a role in steepness of the smash. But it is not the height that contribute power to the smash. I've seen shorter player that gives powerful smash. Its all in the technique and physique.

Originally posted by Phil
Height plays a very important part in smash power. Short people can't hit as hard as taller people simply because their lever for hitting is going to be smaller.

Disclaimer: This does not mean that all short people smash slower than all taller people, but unless their technique is well tuned, this is often the case.

Phil

This opens an interesting "can of worms" :)

While it's true that a longer lever (arm) should provide more velocity at the distal end (racket head) thanks to its length advantage, it may also require more effort (torque) to get it to achieve the same rate of rotation as the shorter lever, due among other things to a higher lever mass (more bone, muscle, etc. to move).

Thus, a weaker tall player might be disadvantaged compared with a stronger short player in at least two ways:

1\ Given players of similar strength, the potential racket head velocity advantage resulting from a longer and likely more massive lever may be entirely negated by a lower rate of rotation (arm velocity).

2\ The tall player may be strong enough to retain some of the velocity advantage but the stroke nevertheless takes longer to accomplish, thus making the long-armed smash unsuitable in certain situations like doubles play. This falls in line with Dill's comments earlier in this thread about using different smash techniques for different situations.

Note: This second case is based on the "transfer of momentum" point of view, whereby momentum (mass * velocity) transfers to the racket when the arm slows down. Since the racket has less mass than the arm, its velocity will be higher than the arm's due to transfer of momentum, i.e. arm (MASS * velocity) ~= racket (mass * VELOCITY), provided this transfer is not overly impeded by poor technique.

This second case also introduces a distinction between the time required to smash and the racket head velocity. A longer smash stroke (time-wise) may produce more racket head velocity but be unsuitable to certain situations like doubles play.

Conversely, a shorter smash stroke (time-wise, e.g. wrist smash) may produce less racket head velocity but be the only suitable type of smash in those same situations.

Cheers,

Mike

Mike,

I agree entirely with your comments about torque. Although I have no knowledge of the intrinsic nature of torque, I know that it involves the force, F, applied to a point x, which is a certain didtance, d, from the lever.

T = F x d. We cannot provide a basic demonstration of this in badminton, because forces are being applied in so many different places. However, assuming that raquets used are all equal, to take an arbitrary point along the arm (around the elbow) shows that the torque required is obviously more for the taller among us.

Now, with regards to your comment about momentum transfer...I'm not sure how befitting it is to the smash. It is true that the arm and the raquet are separate articles, but, as a system, it is a whole. I was taught that momentum transfer is only applicable to separate bodies, as there has to be something to transfer the momentum to. Even if we discussed momentum transfer on a particular level, it would still not apply, as the raquet is almost rigid (it does have some flex) and the particles are only moving incrementally.

What we have here is a series of levers rotating or performing arcs. Consider the hips, spine, shoulder, elbow, wrist and fingers all levers. Within the body, we can talk of momentum transfer on a particular level, as each particle is being displaced enough to transfer momentum. Between the levers, effort is applied, which builds the momentum of the particles, Then we have a very high speed at the end, due to the POSITIVE momentum transferred WITH the levers and EFFORT applied BETWEEN the levers.

This is why we should never induce NEGATIVE momentum whilst smashing, i.e. step backwards, force the shoulder away from the net, as, obviously, the smash will be less powerful.

Nor should we induce momentum which has no effect at all on our smash. As the smash follows a 2-dimensional path, we should really restrict our movements to this 2-dimensional plane to make the smash fully effective. This is "the revelation" Mag came upon a while ago, one which I pointed out before. He discovered that everything must be kept tucked in to transfer all the momentum efficiently.

May I repeat that your insight on torque is well-advised and very helpful, Mike. It was just the stuff about momentum I was confused by. ;)

To summarise, the powerful smash will have made use of all momentum transfers within the body, and so any effort applied between our levers is completely useful. If we work within the direction of the smash, we are being as efficient and direct as we can be. It is when we deviate from the 2-dimensional plane where effort is wasted.

Ttktom, does this answer your question?

Aleik.

I want to try a racquet that is twice as long as a standard badminton racquet. Longer the racquet , the faster the head can travel (given a certain angular velocity). Fast racquet head speed during the moment of "change of momentum" is good for a fast smash.

I do agree with u Gollum the racket makes little difference in terms of power.

There's only one momentum transfer component which is at the point of impact & that's the momentum of the Racquet head. Nothing else.

All the movements of the body change the relative velocity of the racquet head, taking this velocity & calculating the momentum takes into consideration of all the other body movements.

If the momentum of moving backwards affected a smash then a heavy person moving at the same speed as a light person would have more "negative" momentum & the smash would be weaker.
In fact it's the "negative" velocity of moving backwards that changes the speed of the racquet head in relation to the shuttle.
At point of impact you would need to work out the relative momentum of the racquet head as a starting point for calulating power.

All the movements of the body need to co-ordinate to maximise the speed of the rqcquet head.

Originally posted by mindfields
If the momentum of moving backwards affected a smash then a heavy person moving at the same speed as a light person would have more "negative" momentum & the smash would be weaker.

Do we know for a fact that this is not true?
The speed of the person is very small compared to that of the racquet head, so the end result may not be easily seen. And heavy people tend to move slower than light people, so it balances out. :D

hmmm, some quick calculations lead me to think that the difference in mass between body and racquet outweighs the difference in speed, so I guess you're right.

Originally posted by SchrodingerCat
I want to try a racquet that is twice as long as a standard badminton racquet. Longer the racquet , the faster the head can travel (given a certain angular velocity). Fast racquet head speed during the moment of "change of momentum" is good for a fast smash.

Racket length is restricted by regulations. You are not allowed to use a racket more than 68cm in length or more than 23cm in width.

Originally posted by mindfields
There's only one momentum transfer component which is at the point of impact & that's the momentum of the Racquet head. Nothing else.

All the movements of the body change the relative velocity of the racquet head, taking this velocity & calculating the momentum takes into consideration of all the other body movements.

If the momentum of moving backwards affected a smash then a heavy person moving at the same speed as a light person would have more "negative" momentum & the smash would be weaker.
In fact it's the "negative" velocity of moving backwards that changes the speed of the racquet head in relation to the shuttle.
At point of impact you would need to work out the relative momentum of the racquet head as a starting point for calulating power.

All the movements of the body need to co-ordinate to maximise the speed of the rqcquet head.

Mindfields, your explanation is further reinforced by the following:

http://www.racquetresearch.com/angmom.htm

The gist of this article is as follows:

- Impact time is very short
- Movements of the body (e.g. moving backwards, wrist snap, etc.) occurring at impact time will not materially affect results in such a short span of time
- For practical purposes, racquet head momentum (and consequently, its velocity) should thus be considered a byproduct of movements occurring only before impact time

Cheers,

Mike

PS: similar arguments (and research) have been debated in other sports like golf ( and likely tennis) and , AFAIK, the club or racquet head always turns out to be the only thing that matters at impact time, i.e. neither the shaft nor the player's mass or effort.

Originally posted by Aleik
Mike,

I agree entirely with your comments about torque. Although I have no knowledge of the intrinsic nature of torque, I know that it involves the force, F, applied to a point x, which is a certain didtance, d, from the lever.

T = F x d. We cannot provide a basic demonstration of this in badminton, because forces are being applied in so many different places. However, assuming that raquets used are all equal, to take an arbitrary point along the arm (around the elbow) shows that the torque required is obviously more for the taller among us.

Now, with regards to your comment about momentum transfer...I'm not sure how befitting it is to the smash. It is true that the arm and the raquet are separate articles, but, as a system, it is a whole. I was taught that momentum transfer is only applicable to separate bodies, as there has to be something to transfer the momentum to. Even if we discussed momentum transfer on a particular level, it would still not apply, as the raquet is almost rigid (it does have some flex) and the particles are only moving incrementally.

What we have here is a series of levers rotating or performing arcs. Consider the hips, spine, shoulder, elbow, wrist and fingers all levers. Within the body, we can talk of momentum transfer on a particular level, as each particle is being displaced enough to transfer momentum. Between the levers, effort is applied, which builds the momentum of the particles, Then we have a very high speed at the end, due to the POSITIVE momentum transferred WITH the levers and EFFORT applied BETWEEN the levers.

This is why we should never induce NEGATIVE momentum whilst smashing, i.e. step backwards, force the shoulder away from the net, as, obviously, the smash will be less powerful.

Nor should we induce momentum which has no effect at all on our smash. As the smash follows a 2-dimensional path, we should really restrict our movements to this 2-dimensional plane to make the smash fully effective. This is "the revelation" Mag came upon a while ago, one which I pointed out before. He discovered that everything must be kept tucked in to transfer all the momentum efficiently.

May I repeat that your insight on torque is well-advised and very helpful, Mike. It was just the stuff about momentum I was confused by. ;)

To summarise, the powerful smash will have made use of all momentum transfers within the body, and so any effort applied between our levers is completely useful. If we work within the direction of the smash, we are being as efficient and direct as we can be. It is when we deviate from the 2-dimensional plane where effort is wasted.

Ttktom, does this answer your question?

Aleik.

Very well done Aleik. I'll try and dig up that piece of research dealing with this momentum topic to clarify my previous post. In the meantime, you might want to look at the following:

http://www.racquetresearch.com/angmom.htm

Note that it deals with ANGULAR rather than LINEAR momentum since we are talking about rotational, not linear, motion (my previous post also dealt with ANGULAR momentum, I think ;)).

Along the same lines, here is the formula for force in linear motion:

F = mA where m stands for mass of object to be moved and A for acceleration

And the conceptually equivalent force in rotational motion, known as torque:

T = (ml2)A where l is the length of the lever from its axis of rotation (e.g. shoulder, elbow, hand) and A is angular acceleration (radians/seconds^2 where one radian = 360 degrees/2pi or about 1/6 of a circle).

The important point to notice here is that both length and mass will influence the torque (rotational force) needed to achieve a given acceleration, and hence velocity and momentum at impact.

So it's not clear that tall players with longer arms will always be able to smash harder than smaller players (given a similar technique level). This should happen only if they manage to produce enough extra torque to negate their length and mass "disadvantage".

BTW, did I say before that I'm a long-armed 6'3"/1m90 player ? ;)

Cheers,

Mike

Originally posted by Neil Nicholls
Do we know for a fact that this is not true?
The speed of the person is very small compared to that of the racquet head, so the end result may not be easily seen. And heavy people tend to move slower than light people, so it balances out. :D

hmmm, some quick calculations lead me to think that the difference in mass between body and racquet outweighs the difference in speed, so I guess you're right.

Neil, here's some food for tought:

1\ At impact time, one must consider only "effective mass" (typically the racquet or club head) involved in transfer of momentum to the bird, rather than total mass...

2\ We are dealing with rotational, not linear motion, and hence torque acting on the mass and length of a lever from an axis of rotation (shoulder on upper arm, elbow on forearm, wrist/hand on racket)

So I guess the player's bodily mass would have to be shown to influence for example shoulder torque on upper arm...

Cheers,

Mike

Mindfields,

May I correct you on the momentum transfer thing. If we talk in terms of particles being displaced, or even parts of the body being displaced, there is momentum transfer, even though the articles are joined. Anything of mass which is acted upon by a force experiences a change in momentum. This momentum is, as you say, transferred to the shuttle at the end.

I can't believe I've forgotten most of my further maths A-level after about 9 months! I'm sure it can be applied in even more situations?

Aleik.

Originally posted by Aleik
Mindfields,

May I correct you on the momentum transfer thing. If we talk in terms of particles being displaced, or even parts of the body being displaced, there is momentum transfer, even though the articles are joined. Anything of mass which is acted upon by a force experiences a change in momentum. This momentum is, as you say, transferred to the shuttle at the end.

I can't believe I've forgotten most of my further maths A-level after about 9 months! I'm sure it can be applied in even more situations?

Aleik.

Don't worry Aleik, this is the kind of stuff that can be easily (and gladly) forgotten in a matter of weeks. :p

BTW, I've found another source that discusses how the tip of a bullwhip actually exceeds the speed of sound even though the initial force exerted by one's hand is not that impressive. This example is based on the transfer of kinetic energy but the rationale is along the same lines as the momentum one, i.e. only mass and velocity are involved:

Kinetic Energy = (mass * velocity^2) / 2
Linear Momentum = mass * velocity
Angular Momentum = moment of inertia * angular velocity
Moment of Inertia = mass * lever length^2 from axis of rotation (simple case with even mass distribution, calculus is required otherwise)

Picture said bullwhip as a series of very small levers with decreasing mass. Kinetic energy transfers from "lever" to "lever" (a small amount is lost as heat) as each preceding lever slows down. Once again velocity increases "on its own" because each lever's mass decreases.

Likewise, the smash stroke can be pictured as a three lever system (upper arm, forearm, and racket), each of decreasing mass where each lever's velocity increases on its own through (momentum or) kinetic energy transfer.

Muscular action may add further torque at each joint with positive results as long as it does not overly impede the transfer of kinetic energy (or momentum). Picture a stiff-armed beginner versus a seasoned pro with whip-like arm action...

Cheers,

Mike

Originally posted by Aleik
Mindfields,

May I correct you on the momentum transfer thing. If we talk in terms of particles being displaced, or even parts of the body being displaced, there is momentum transfer, even though the articles are joined. Anything of mass which is acted upon by a force experiences a change in momentum. This momentum is, as you say, transferred to the shuttle at the end.


Aleik.

Correction? Er, I did say there is momentum transfer, 1 component, the momentum of the racquet head.
This racquet head momentum is a calculation of racquet head velocity & mass.
Racquet head velocity is based upon all of your body movements & racquet flex.

Moving backwards will cause a weaker smash not because of your bodies backward momentum but because of it's backwards velocity slows down the racquet head velocity relative to the shuttle.

Exagerating my example. using a 100g racquet.
If you stood on top of a 10 tonne train traveling at 1m/s the negative momentum is 10,000 kg.m/s
If your being pushed in a 10kg supermarket trolley it's only 10kg.m/s
The momentum has nothing to do your smash it's the 1m/s backwards movement.

Same thing with k.e. neither of the k.e. of these components have anything to do with the final product. it's the velocity that affects the final equation.

You dont' take away 10,000kg.m/s of momentum from the racquet head momentum you take away 1 m/s from the racquet head velocity.
This means: 1m/s x 0.1kg =0.1kg.m/s loss of momentum in racquet head momentum.

(k.e. loss is more difficult to calculate as it's a square function & would be (v-1)^2 & we don't know v)


The whole point is you your body movements affect the movement of the racquet head. movement is a "displacement" or "velocity". Movement has no mass e.g m/s , mph,

Originally posted by mindfields
Same thing with k.e. neither of the k.e. of these components have anything to do with the final product. it's the velocity that affects the final equation.


Well mindfields, I know of at least one Professor Emeritus in Physics (Theodore Jorgensen, Phd) that would disagree with you on this one. :p
__________________________________

We are likely all familiar with basic physics principles of LINEAR movement:

- A force (force = mass * linear acceleration) applied to an inertial body accelerates said body and hence increases its linear velocity (and its linear momentum since momentum = mass * velocity).
__________________________________

Although we are likely less familiar with principles of ROTATIONAL movement, some concepts map easily to the above:

- A torque (torque = moment of inertia * angular acceleration) applied to an inertial body accelerates the rate of rotation of said body (angular acceleration), increases its angular velocity (speed with direction) and thus its angular momentum (moment of inertia * angular velocity). Recall that moment of inertia (MOI) is simply another way of stating mass by expressing the rotating body's mass distribution.
__________________________________

Another important phenomenon applies to rotational movement besides torque (one modeled by Prof. Jorgensen through a hefty dose of differential equations in a sports physics book involving rotational strokes), i.e. the transfer of kinetic energy ((mass * velocity^2) / 2).

To be more specific, it applies to situations involving levers where proximal levers (closest to the initial axis of rotation) possess more mass than distal levers (furthest from the initial axis of rotation).

As each proximal lever slows down, the next lever gains its kinetic energy (with small losses through heat, etc.) but since its MASS IS LESS than the previous lever, its VELOCITY MUST INCREASE to satisfy the equation above.

Some sports strokes can thus be modeled as two-lever rotational systems (e.g. straight arm and club in golf) and others as three-lever rotational systems (e.g. baseball, tennis, and badminton with upper arm rotating from the shoulder, then forearm from the elbow and bat/racket from wrist/hand).

The ultimate illustration of this phenomenon is that of a bullwhip (modeled as a series of very small levers by said Prof. Jorgensen to illustrate the principle to us mere mortals :D), where the tip velocity exceeds the speed of sound, something that cannot be explained solely by the initial torque supplied by the hand.

The same principle also explains why the distal lever of a martial arts weapon (two or three sticks linked together) will travel much faster than a straight stick of equal length given a similar effort (torque) by its wielder.

Our now clearer understanding of those principles also explains why a 13 year-old girl (Michelle Wie) hits a golf ball some 40 yards (35 meters) further than golf pros of one decade ago while giving the impression of "swinging effortlessly".

She did not have to build a huge muscle mass or do wrist curls to come up with Hulk-like wrists...she simply sequences her swing to take the fullest possible advantage of this "free" source of velocity.

Cheers,

Mike

Yikes, looks like another of those details discussions. ;)

On review we're talking about different things.
I guess I'm getting misled with your defnition of "transfer" which i would class as "generation".

What I'm talking about is when momentum & k.e. is transfered to the shuttle
Your talking about generating that momentum/k.e in preperation for the transfer.

Different things entirely but we're pretty much discussing the same fact.

My point was the momentum of your body at time of impact doesn't factor in the calculation in the transfer of momentum of the racquet head to the shuttle.

The reason for this is that the calculations for the momentum of the racquet head has already taken into account all the bodies movements through all your calculations.

It's statements like:
As each proximal lever slows down, the next lever gains its kinetic energy (with small losses through heat, etc.)
That seem to me imply that the next lever gains *all* the kinetic energy/momentum which are what I have issues with.
The next lever gains *some* kinetic energy due to the relational increase of velocity which increases the 2nd lever's k.e.

If the rotational speed is constant due to your muscles constantly putting work into your arm then momentum/k.e. in your arm doesn't change but the racquet speed does. There's no change of momentum/k.e. so what has been transfered?

Mindfields,

I acknowledged that the main and obvious momentum transfer was from the raquet head to the shuttle as you said. Don't worry, I wasn't correcting you on that. ;)

I was correcting you on the smaller changes of momentum within the body, which do exist.

There's only one momentum transfer component which is at the point of impact & that's the momentum of the Racquet head. Nothing else.

You are certainly correct in saying that the entire body's momentum has little effect on the speed of the raquet, because, as a whole, the body's momentum should be almost nil. Of course, we don't throw our entire bodies towards the net to add even more speed to the raquet! It is the other movements of the body which balance these positive momentum changes out; for instance, pointing up with the left arm when doing a backswing, etc.

Sorry for the misunderstanding, and sorry for missing these details out.

Aleik.

Originally posted by mindfields
Yikes, looks like another of those details discussions. ;)

On review we're talking about different things.
I guess I'm getting misled with your defnition of "transfer" which i would class as "generation".

What I'm talking about is when momentum & k.e. is transfered to the shuttle
Your talking about generating that momentum/k.e in preperation for the transfer.

That's exactly right, which is why I supported your point of view earlier in this thread concerning velocity and momentum transfer at impact time, i.e. that whatever happened BEFORE impact time is already expressed in the resulting racquet head velocity.

So my rationale picks up from there and summarizes some sports-related research I'm familiar with that explains how said velocity is achieved in the first place.

So let's see if the sequence of events can be examined backwards (while adding a few additional twists) :D :

1\ Since impact time is very short, some factors (like the contribution of a flexible or stiff shaft) should play a negligible role and may likely be ignored. This introduces the notion of "effective mass", i.e. the subset of racquet mass that produces an IN-LINE force vector on the bird (a glancing blow involves less effective mass than a square blow because the force vector is not aligned with the bird's flight path).

For example, in golf the clubhead is the only meaningful source of mass considered at this point, so let's assume that the raquet head and stringbed play a similar role here (this approximation will likely be closer to the truth than considering the entire racquet mass).
_________________________________

2\ At impact time, a "slow" head-heavy racquet (MASS * velocity) should thus produce the same bird velocity (through transfer of momentum) as a fast head-light racquet (mass * VELOCITY) as long as the product of their respective mass and velocity (i.e. momentum) remain equal.

Note also that a head-heavy racquet should always be slower given a similar torque because of its higher moment of inertia (swingweight).
_________________________________

3\ This velocity should come from at least three sources:

A\ The fact that the axis of rotation, a.k.a. fulcrum (wrist/hand) is already traveling forward

B\ The fact that the previous lever (forearm) is slowing down, thus thrusting the racquet forward through transfer of angular momentum/k.e. (Prof. Jorgensen uses k.e. but others discuss momentum. Whether the latter is technically correct or not, similar parameters are involved in both cases, i.e. mass and velocity).

This is the part where velocity INCREASES ON ITS OWN because of the racquet's smaller mass compared to the forearm.

C\ Additional torque produced by wrist muscles, provided that C does not prevent B from happening. More research indicates that optimal results are achieved at around 30% of one's strength.

D\ Something along the lines of A, B, and C should apply in dealing with forearm (and elbow) versus upper arm and upper arm (and shoulder) versus body. I fully agree that some kinetic energy will be lost during each of these transitions.

To conclude, note that a flail or martial arts weapon consisting of two or three linked sticks achieves tremendous velocity even though point C above is not involved...

Cheers,

Mike

Originally posted by Aleik
Of course, we don't throw our entire bodies towards the net to add even more speed to the raquet! Aleik.

Indeed, but then you do start with your non-racquet foot forward and turn your hips and shoulders (jeez, let's rotate the entire body :D) during the stroke don't you ?

This produces ANGULAR momentum (whether it's a significant parameter or not is another manner)...

Think ROTATIONAL physics, not LINEAR physics...;)

Cheers,

Mike

Originally posted by mindfields
If the rotational speed is constant due to your muscles constantly putting work into your arm then momentum/k.e. in your arm doesn't change but the racquet speed does. There's no change of momentum/k.e. so what has been transfered?

I may be interpreting this statement wrong but a continuous application of force/torque results in an increase in velocity and momentum (acceleration). Velocity and momentum will remain constant only in the absence of further torque...

Cheers,

Mike

Originally posted by mlvezina


1\ Since impact time is very short, some factors (like the contribution of a flexible or stiff shaft) should play a negligible role and may likely be ignored. This introduces the notion of "effective mass", i.e. the subset of racquet mass that produces an IN-LINE force vector on the bird (a glancing blow involves less effective mass than a square blow because the force vector is not aligned with the bird's flight path).


I don't agree if you take it to the limit, an extremely flexible shaft would deflect no matter how short the impact time. Also the impact time is directly a function of string tension.


_________________________________

2\ At impact time, a "slow" head-heavy racquet (MASS * velocity) should thus produce the same bird velocity (through transfer of momentum) as a fast head-light racquet (mass * VELOCITY) as long as the product of their respective mass and velocity (i.e. momentum) remain equal.

Note also that a head-heavy racquet should always be slower given a similar torque because of its higher moment of inertia (swingweight).

Mike

Whilst this is theorectically correct, but simply because of the limitations of the human body you can say that heavier racquets will produce higher shuttle speeds if you have the strength to use them. Simply put you will eventually (with "perfect technique, etc) reach a maximum swing speed, ie that of your unladened arm, you won't be able to swing significantly faster regardless of how light your racquet is. For example comparing the acceration of you wrist with an unladened palm, to one holding a 10 gram weight and the difference would be almost unnoticable. However an extra 10 grams on the head of a racquet (assuming you are stronger enough to use it, ie say the difference between a 40 g and 50 g racquet [1]), for almost no difference in swing speed would cause significant improvement in shuttle speed.

Where this differs from golf is that whilst in golf the head has a much higher mass moment of inertia around the pivot compared to the shaft, in badminton this is not so.

[1] Racquet weights are for illustrative purposed only, I don't claim that there are any racquet this weight, however the theory holds regardless.

Originally posted by Pecheur


I don't agree if you take it to the limit, an extremely flexible shaft would deflect no matter how short the impact time. Also the impact time is directly a function of string tension.



Whilst this is theorectically correct, but simply because of the limitations of the human body you can say that heavier racquets will produce higher shuttle speeds if you have the strength to use them. Simply put you will eventually (with "perfect technique, etc) reach a maximum swing speed, ie that of your unladened arm, you won't be able to swing significantly faster regardless of how light your racquet is. For example comparing the acceration of you wrist with an unladened palm, to one holding a 10 gram weight and the difference would be almost unnoticable. However an extra 10 grams on the head of a racquet (assuming you are stronger enough to use it, ie say the difference between a 40 g and 50 g racquet [1]), for almost no difference in swing speed would cause significant improvement in shuttle speed.

Where this differs from golf is that whilst in golf the head has a much higher mass moment of inertia around the pivot compared to the shaft, in badminton this is not so.

[1] Racquet weights are for illustrative purposed only, I don't claim that there are any racquet this weight, however the theory holds regardless. [/B]

Pecheur,

As ever, you mention excellent points. However, while I fully agree that more head weight will produce more shuttle speed ("assuming one is stronger enough to use it"), I do believe I mentioned an assumption of similar strength (i.e. "given a similar torque") ;)

I should also point out that you introduced an interesting additional parameter by mentioning "heavier racquets", something distinct from my "head-heavy" vs. "head-light" point.

Cheers,

Mike

Originally posted by mindfields
Yikes, looks like another of those details discussions. ;)

On review we're talking about different things.
I guess I'm getting misled with your defnition of "transfer" which i would class as "generation".

What I'm talking about is when momentum & k.e. is transfered to the shuttle
Your talking about generating that momentum/k.e in preperation for the transfer.

Different things entirely but we're pretty much discussing the same fact.

My point was the momentum of your body at time of impact doesn't factor in the calculation in the transfer of momentum of the racquet head to the shuttle.

The reason for this is that the calculations for the momentum of the racquet head has already taken into account all the bodies movements through all your calculations.



Here are a couple of URLs to clear things up concerning the transfer of ANGULAR momentum I was referring to in my original post:

http://www.bsu.edu/web/ykwon/pep294/notes/akin.html
http://www.cwu.edu/~acquisto/NLangular.htm

And here's a quote from the second URL above:

"Angular momentum can be transferred from one body segment to the next. Since body segments differ in mass, the moment of inertia of each body will vary. Considering that momentum is conserved, a reduction in the moment of inertia of a body part will result in an increased angular velocity. The latter can be applied to throwing and kicking movements. For example, throwing involves a series of angular rotations of progressively lighter body segments (leg/trunk--arm). A reduction in moment of inertia between the leg/trunk complex and the lighter arm, results in an increased velocity of the arm."

So we are really talking about momentum transfer...but of the angular (not linear) variety. A Google search with "angular kinetics" seems to yield useful sites.

To summarize:

An understanding of angular kinetics as they apply to badminton strokes (or any sport involving circular strokes) helps one understand why some players generate tremendous smash velocity in a seemingly effortless fashion. A proper sequencing of movements yields "free" velocity without undue muscular effort.

Using golf as an illustrative example (because its easier to illustrate this point using the distance of a golf ball than the speed of a bird), proper use of angular kinetics also allow a 13 year old girl (Michelle Wie) to hit a golf ball close to 300 yards in a seemingly effortless fashion whereas big muscular guys manage only some 200 yards.

Proper use of angular kinetics also explains why figure skaters spin faster by simply bringing arms and legs closer to the axis of rotation, why platform divers spin faster by going into a tuck while diving, etc.

Cheers,

MIke

Originally posted by mindfields
Yikes, looks like another of those details discussions. ;)

On review we're talking about different things.
I guess I'm getting misled with your defnition of "transfer" which i would class as "generation".

What I'm talking about is when momentum & k.e. is transfered to the shuttle
Your talking about generating that momentum/k.e in preperation for the transfer.

Different things entirely but we're pretty much discussing the same fact.

My point was the momentum of your body at time of impact doesn't factor in the calculation in the transfer of momentum of the racquet head to the shuttle.

The reason for this is that the calculations for the momentum of the racquet head has already taken into account all the bodies movements through all your calculations.



Here are a couple of URLs to clear things up concerning the transfer of ANGULAR momentum I was referring to in my original post:

http://www.bsu.edu/web/ykwon/pep294/notes/akin.html
http://www.cwu.edu/~acquisto/NLangular.htm

And here's a quote from the second URL above:

"Angular momentum can be transferred from one body segment to the next. Since body segments differ in mass, the moment of inertia of each body will vary. Considering that momentum is conserved, a reduction in the moment of inertia of a body part will result in an increased angular velocity. The latter can be applied to throwing and kicking movements. For example, throwing involves a series of angular rotations of progressively lighter body segments (leg/trunk--arm). A reduction in moment of inertia between the leg/trunk complex and the lighter arm, results in an increased velocity of the arm."

So we are really talking about momentum transfer...but of the angular (not linear) variety. A Google search with "angular kinetics" seems to yield useful sites.

To summarize:

An understanding of angular kinetics as they apply to badminton strokes (or any sport involving circular strokes) helps one understand why some players generate tremendous smash velocity in a seemingly effortless fashion. A proper sequencing of movements yields "free" velocity without undue muscular effort.

Using golf as an illustrative example (because its easier to illustrate this point using the distance of a golf ball than the speed of a bird), proper use of angular kinetics also allow a 13 year old girl (Michelle Wie) to hit a golf ball close to 300 yards in a seemingly effortless fashion whereas big muscular guys manage only some 200 yards.

Proper use of angular kinetics also explains why figure skaters spin faster by simply bringing arms and legs closer to the axis of rotation, why platform divers spin faster by going into a tuck while diving, etc.

Cheers,

MIke

If I use a lighter racquet (vs. a heavy racquet), I can get a faster racquet angular velocity. ( I swear I notice the differences)

Also I can imagine if i have a heavy chest (lot of muscle and FAT) and a BIG FAT belly, and transfer their angular momentum to arm and racquet, I can get a faster and harder smash.:p

:)

Originally posted by SchrodingerCat
If I use a lighter racquet (vs. a heavy racquet), I can get a faster racquet angular velocity. ( I swear I notice the differences)

Also I can imagine if i have a heavy chest (lot of muscle and FAT) and a BIG FAT belly, and transfer their angular momentum to arm and racquet, I can get a faster and harder smash.:p

:)

Well, I imagine that one could model that McDonaldesque body as one big lever running from left hip to right shoulder (for a rightie) for the sake of simplicity.:p

So, given that both momentum (angular or linear) and torque involve mass and velocity, i.e. (simple formula versions with equal mass distribution):

Angular Momentum = (mass * lever length^2) * angular velocity
Torque = (mass * lever length^2) * angular acceleration

Two players (Skinny and Beefy) producing equal torque from their legs (or whichever other body parts are involved in applying torque to this lever) then Beefy's shoulder angular velocity would be proportionately less given the increase in mass.

Now, how would both players' angular momenta compare ?

Cheers,

Mike