Saturday, 19 July 2008

Badminton Rackets and Injuries

Badminton involves throwing your badminton racket very quickly at the shuttle, it is the one racket sport that creates the most violent actions on your body, especially your shoulder and arm. The result is that many players pick up injuries to their shoulders. Most of these injuries are caused by repetetive movements, and are usually chronic, meaning they are permanent. The longer you play the more likely you are to pick up these kinds of problems. I am in the same situation. Many badminton players are too, so you know what i am talking about.

So i decided to find out if a badminton racket had any influence on the potential to cause injury. What is the best racket to use, to help reduce injury? Well let's find out...

To find this information i have looked through many different articles from academic journals on racket science, physics and sport. I have been to the British Journal of Sports Medicine, and looked through Google Scholar for the answers. A few names keep cropping up, and they are the leading academics who have researched this topic.

I am not, in any way, a maths or physics expert, to be honest with you, i hate the subjects. But to find out some answers i thought it necessary to at least have a look at this stuff.

The first term that came up was work. Work is the energy required to produce a certain shuttle speed. It measures the efficiency of the badminton racquet. What you want is a racket that has low work, high work is bad because the player has to swing harder to achieve the same result. Work is the racket's power, the less work you have to put in to get the required shuttle speed the better.

Shock is the loading of the racket from a sudden change in kinetic energy on impact, ie, vibration. It is how much the racket slows down when it hits the shuttle. Before impact you need energy to get up to speed to hit the shuttle. After impact the racket moves slower and energy is lost. The shuttle gets some of the energy, and the rest is used in bending the frame. If the frame is stiff and light, the frame bending energy will not be absorbed by the frame, it will be dumped into your arm. High shock is bad for injuries.

Now, all the research has indicated that the best kind of racket to use to gain maximum power is a heavy racket with a head light balance. More mass placed close to the handle will allow this kind of bat to be swung faster. More mass at the tip of the racket makes it more difficult to swing. An example of this can be seen in a sledgehammer. All the weight is placed at one end, and if you have ever tried to swing a sledgehammer you will know that it is very difficult, you are often thrown off balance because of the weight at the tip. If you hold the sledgehammer the other way round, with the weight in your hands, it is much easier to swing it.

There is a bit of conflicting evidence about this from what i have seen. Some people argue that a lighter racket will allow you to swing faster, and therefore you will have greater velocity on impact, which in turn will give increased shuttle speed. Heavier rackets will have more mass, but will not have as much swing speed on impact. So in this instance, it appears that you would get the same shuttle speed using one or the other. The lightweight racket can be swung quicker but does not have the mass, and vice versa. However swing speed is not the key, momentum is what counts in a collision, and the research shows that it is better to have more mass, and particularly more mass closer to the handle of the badminton racket to achieve more power and less potential for injury.

The advocates of lightweight rackets claim that this extra swing speed equals more shuttle speed on impact, and to a certain extent this is true. But.. faster swing speed on impact means less control, and more importantly, a lightweight racket will slow down much quicker on impact, causing more stress to your shoulder. Over time that light weight will demolish your arm, as you are having to do more work to get the performance, not the racquet.

So why not have a head heavy balance and light weight? It would seem that you could get the most performance with this type of bat. The problem is that it requires more effort on your part to swing it, you have to work a lot harder to achieve a certain shuttle speed than with a heavy head light bat. Rememeber the sledgehammer example. Another drawback is that head heavy racquets feel sluggish.

Here is the low down... Head light and heavy is best for performance, and best for avoiding injury.

The research also shows that the worst kind of racket you can use for injury is a lightweight racket with a head heavy balance, and a stiff frame. Does this type of racket sound familiar? All the most expensive and popular racquets have these characteristics. The current trend is to have head heavy balance, and the manufacturers market this all the time.

As an example, i have looked for the specifications for Yonex rackets in relation to their balance points. I have used a table of reference from badminton central, which lists many of today's most popular badminton rackets. According to this information, not one single Yonex model has a head light balance. Many are head heavy, such as the Muscle Power series, whilst the Nanospeed series appears to be slightly head heavy, or evenly balanced. It would appear that an even balanced racket is better for you than head heavy. Better yet, a heavier overall weight is good, even with an even balance.

Next time you look for a new bat take this information into consideration. How many times have you seen people go into their local shop and pick a racket up, swing it round a bit and then say "wow, that is so light, i think i'll buy it". Their entire basis for buying is based on how light it is. This kind of ignorance has caused so many injuries. And don't think the store owner will try and put you off buying a lightweight racket, i guarantee that most of them will not even know what balance the racket is, all they are trying to do is sell you that racquet. They will certainly not know what you know if you have read this.

So, what can you do to make your racket into a powerful, injury preventing weapon? Add weight to the handle. You can do this by adding extra grip tape. If your the kind of player who buys a racket and then applies large amounts of overgrip on the handle, you will have changed the balance point, probably without even realising. Many professional players seem to have overgrip going upto half way up the shaft. The Indonesian players favour this. The extra grip is also to help them hold the racket further up the shaft for more control, but they have also changed the balance point with all this overgrip.

There is also a little gimmick called lead tape, and the idea is to apply this tape to the racket head. This will create a head heavy balance. Many players use this tape as they believe it will give them more power. We now know that all this lead tape will do, is to make it more difficult to swing the bat, and cause the most injury to your shoulder over time. What i would do is buy some of this tape and apply it to the handle, then put the overgrip on top of it.

Next time you buy a new badminton racket make sure you know all the details about it, such as weight and balance. Specify what weight and balance point you want. If your not sure what this means, just browse through some of the previous posts. Remember, more weight is not a bad thing.

Just as a side note i have learned a lot myself from doing this research. My current racket of choice is the Carlton Airblade Tour and it weighs in at 78g. Now from what i have just told you, this racket is probably far too light to get maximum power. The result of me using this racket is that i have got shoulder problems. I have been putting in all the work to get any sort of power from it. The only plus point is that it is head light, but it is so light overall that it makes it very difficult to extract power. No wonder i have shoulder problems.

If i want to carry on playing badminton i will need to change rackets, to give my shoulder the best chance of survival. The performance difference between the many racquets is very small, changing from one to another should not be a problem, technique does not change when you change rackets does it? What i am interested in, is prolonging my playing days, and if that means using a heavier badminton racket and placing more weight on the handle then this is what i will do. It is time to start experimenting...

8 comments:

Rockstar said...

Cool, cheers Antony I know now why I have got a bad sholder I always thought head heavy = more power

antony said...

Glad to help Rockstar!!

Anonymous said...

Very good article. I am happy that my racket is head ligth and I am going to put some more weight on the hand to see if I can generate more power with it.

What is the outcome of your experiments? Do they confirm the findings? I noticed in more recent article that you were interested in buying tantrum 300, which is stiff and head heavy. So how does this racket go with the research?

antony said...

Hi there

The experiments worked very well for me. Only a small amount of weight is needed on the bottom of the handle, not too much. Try it and see for yourself! I would also be very interested to know your own results when you do this. Any racket that is head heavy can be balanced back with the extra weight on the handle, so although it still has the weight in the head, you don't feel that it has. Good luck.

Anonymous said...

Hi again,

I experimented with my Browning Oxilite 75 by adding some lead to the handle. I make a little 20g coin out of the lead which placed at the bottom of the cap. It might sound a lot but the racket was kind of too light for me. The results are very good. It is much easier for me to swing the racket faster, and since Oxilite 75 has a medium flex, I can feel how it whips the shuttle hard (at first I had some timing problems). I also feel that I increased the racket’s manoeuvrability which helps me with defence and net playing. And like you say the racket doesn’t feel very heavy at all. Some people can’t believe my racket is as heavy as some cheap head heavy tempered steel rackets.

I would like to thank you for your help and would like to add that it is a good idea to experiment with a lead tape on a cheap racket to learn more about your preferred specs before you start looking for an expensive racket. Lead tape can also make not so expensive racket perform like expensive ones, so why pay more?

Konrad

Anonymous said...

which were the articles and names of key researchers into the physics of badminton rackets? links would be very helpful, need them for research into materials used in badminton rackets

dt said...

Excellent article bro!!!

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