Let’s face it. Everyone wants to hit harder and faster in badminton. Whether it is the five year old kid with a racket as big as himself or a professional badminton player, everyone wants to hit the shuttle faster. However, not everyone can. Now if you ask someone why they can’t hit faster, the most common answer you’ll get is – ‘Well, I’m not strong enough’. And it seems to make logical sense – if someone is not strong enough, i.e., cannot produce large amounts of force, they won’t be able to hit harder.
But consider this - the top badminton players in the world mostly have a physique like A and not B.
Obviously, Arnold (B) is very strong and can most certainly produce more force from every single muscle compared to the players in A. However, I have seen people who are heavily built, but still can’t hit the shuttle very fast and I’m sure you have too. On the other hand, the player smashing in A (Fu Haifeng) is known to have hit smashes faster than 350 kph. So, just producing a large amount of force is not important.
So what makes these lightning fast shuttle speeds possible? Let’s dive deeper into this.
Firstly, let’s change our problem statement a little bit: Our final aim is not to generate more force with our muscles, it is to maximize shuttle speed. The only thing that comes in contact with the shuttle is the racket, so our aim is actually to maximize racket speed. Assuming that the racket-shuttle contact is fairly central (near the racket’s sweet spot), the faster racket speed will cause the shuttle to fly off the racket faster.
Which brings us to our main question – How do we maximize racket speed?
Badminton rackets today weigh around 75-85 grams, which is fairly light. However, we still want to generate very fast racket speeds with these light rackets. For example, research has found that to generate a smash speed of approx. 320 km/h, we need a racket speed of approximately 200 km/h at the instance of racket-shuttle contact. Also, refer to the picture below and you can see that at the end of the backswing, the racket is at rest (zero velocity).
From this position of zero velocity to racket shuttle contact, there is a very limited time in which the racket needs to be accelerated from zero to a very high velocity. Now, to do this we need a lot of force to be generated by our muscles, but in a very short time period and causing very fast speeds.
Now, there are two interesting considerations here:
One, the muscle groups closest to the racket (muscles near our fingers and wrist) are smaller in size. This means that the maximum amount of force they are capable of generating is also very limited (smaller muscle size = less muscle fibres = lesser force capacity) and not enough to generate the fast racket speed (about 200 km/h) that we need.
Two, not only are the muscle groups smaller in size, the intrinsic property of all our muscles is that the faster the speed of movement, the smaller is the force that the muscle can generate (think back to when you were lifting very heavy weights in the gym; the heavier the weight you want to lift, the slower is the overall movement).
Considering these two points, we can conclude that the muscles that are located directly next to the racket are not capable of generating all the force we need on their own.
And this is where a very important biomechanical principle comes into picture.
Located proximally (means ‘closer to the centre of the body’), we have bigger muscle groups (core, back, chest muscles etc.). These muscle groups being bigger in size, have the ability to generate a large amount of force which is significantly larger than the smaller muscle groups near the racket. Now, the way our skeletal structure is designed has every segment connected to every other segment, either in direct contact or through another segment in between. This seems very obvious – of course, everything is connected. But what this connection does is that force can transmit from one part of the body to another.
So firstly, the force generated by the larger muscles sets causes these larger segments (pelvis, trunk etc.) to start moving. As these segments are linked by joints and soft tissues (muscles, tendons, ligaments) to the segments located closer to the racket (upper arm, forearm, hand), the effect of force from the bigger segments causes the smaller segments to also start moving.
This speed increases even more as all the smaller muscles between the trunk and the racket (i.e. muscles of the upper arm, forearm, hand) also start generating their own force and add the effect of their force to the total speed. And this collective effort which travels from the centre of the body towards the racket creates the tremendous racket speeds that we need.
The picture below helps you visualize this better.
Here is another great link to visualize how force transmits in a smash by some amazing researchers at Loughborough University.
This mechanism by which the connected nature of our skeletal structure allows force to transmit from one part of the body to another is called – the kinetic chain. And the presence of this kinetic chain is why good technique for any stroke is much more capable of generating faster shuttle speed than just being strong. Of course, being strong is helpful, but not as much as technique because good technique means being able to generate the necessary force from the necessary muscles at precise timings with respect to the shuttle location.
Just to clarify, our aim here is not to discuss the ideal technique or timing of movement for any stroke, but to discuss the general principle behind generating higher racket speed. For a detailed discussion on technique for badminton strokes, check out our full course here.
The message we want to communicate is this – generating faster racket speeds in badminton is a joint effort by a combination of multiple segments and muscle groups. Larger muscle groups start the force generation and the effect of this travels from them towards the racket. Coordinating all of these complex movements precisely is having a good technique.
So, the next time you try to hit the shuttle faster in any stroke, don’t just focus on hitting harder or getting stronger. Work on your technique.