How do Muay Thai boxers achieve maximum power from a straight punch to increase their ability of a knockout?

Muay Thai fighting similarly to boxing is a sport of agility, speed, endurance and of course power, with the main objective being to protect one’s self whilst striking the opponent using punches, kicks, knees and elbows. The most efficient and desirable way of ensuring a victory in a Muay Thai match is through means of a ‘Knockout’ in which the opponent is incapacitated and disqualified through a powerful strike.  A common knockout strike in Muay Thai and of course traditional boxing is the ‘straight punch’, when the athlete strikes with their preferred hand of their stance  e.g. the right hand.

To achieve a powerful punch means the athlete must be able to produce the most force with their fist by accelerating the fist as fast as possible and with as much mass as they can behind it, so with their body they can create the most force possible to create momentum which they will transfer to their target. (Walilko 2005), (Mack 2010)

Newtons laws

F=mass x acceleration

Momentum (p) = mass x velocity

(Blazevich 2010)

So how does a Muay Thai fighter achieve this force? 

A fully extended Muay Thai straight punch. (http://www.muaythaiauthority.com/2010/10/wck-muay-thai-pala-results-grachev-and.html)

 There are many biomechanical principles that a Muay Thai fighter will employ as a part of their technique in order to efficiently produce Force and Momentum. the following section will outline the biomechanical principles behind the movement as it is broken down into a sequence. 

SEQUENCE OF MOVEMENT  

1) Stance is important to ensure the correct technique of the straight punch, the feet should be placed just outside of shoulder width, dominant leg at the back with weight evenly distributed between the feet and the knees slightly bent. This ensures the fighter is balanced with a controlled centre of gravity and has there legs slightly flexed at the knee (approx. 60°) ready to create momentum. The arms are abducted at the shoulder anteriorly and the elbows in flexion (approx 70-80°) to bring the hand to the chin and create potential for muscle and tendon energy. 
(Djurdjevic 2008)

                                                     

2) Beginning the movement the fighter pushes against the ground with their back, dominant foot extending the leg and pushing from the ball of the foot, which in turn rotates the right side of the hip forwards in an anticlockwise direction.

(Djurdjevic 2008)

 

3) The rotation of the hips is followed by a rotation of the shoulders as the fighter stabilizes their movement and the left side of the body rotates and retracts to balance the right side. The fighters core stabilizes and only moves minimally and momentum is transferred to the right shoulder.
(Djurdjevic 2008)

 4) Finally, the fighter extends the arm to almost a full extension in a fast whipping motion (similar to the snapping motion of a towel) and so the fists displacement is in a straight as possible line, the fist should be thrown through the visualised target, punching bag or opponent to ensure that the momentum is transferred to the target. The left hand retracts to a tucked position at the chin.(Djurdjevic 2008)

 5) The arm is retracted and feet positioned back into the original stance. 

 

 

                                               Steps 2, 3 and 4 viewed from the front. 

Summation of forces, the kinetic chain.

The movement of a straight punch employs a throw-like pattern as opposed to a push-like pattern. (thus the term, ‘throwing a punch’!) as the kinetic chain on the body is open during the movement and the steps of body movement start sequentially from the ground, through the feet, legs, hips, torso, shoulder and finally the extension of the elbow where the proximal parts of the arm continue the momentum and transfer to the most distal part of the arm, the fist, were the greatest velocity is achieved. This is known as a summation of forces and can be seen through the pictures and description of the movement sequence. (Blazevich 2010), (Mack 2010)

Conservation of angular momentum

For every angular reaction there is an equal and opposite angular reaction. In the case of the straight punch the right hip and shoulder rotate and the arm extends, this leads to the left hip and shoulder rotating to the left and the left arm flexing to bring the hand to the fighters chin, this conserves momentum and increases velocity of the right fist and keeps the fighters balanced in their centre of mass. (Blazevich 2010)

Muscle – tendon elasticity

The speed achieved at the fist is built from the momentum of the kinetic chain, energy produced from the muscles and elastic energy stored in the muscles tendons. These tendons play the final part in extending the arm at high speed and throwing the fist. Flexion at the elbow and a retracted arm stretches the tendons to create potential elastic energy which creates higher speed movement than the shortening of muscle fibers can achieve. (Blazevich 2010)

How does the fighter transfer this force to their target?

So now that it has been established how a Muay thai Fighter can create a a high force punch with the correct technique, how do we explain how the momentum is transferred to the opponent to achieve the initial goal of a ‘knockout’? 

The impulse – momentum relationship

Impulse is important in determining how the momentum of a fighters punch will transfer into the target. It is determined by measuring the amount of force by the time it is applied, e.g. a large amount of force applied over a longer time frame would result in a push like movement, so to achieve a movement that hits hard rather than pushing a high impulse is key. (Blazevich 2010)

Impulse = Force x time

Force = Impulse / time

(Djurdjevic 2008)

Using these equations it can be explained that to transfer the maximum amount of momentum from the fist to the target requires the fighter striking with the highest amount of force over the shortest time. To achieve this the fist should be at its maximum velocity at the moment of impact, which will take place before the arm reaches full extension or is stopped and pulled back by the fighter. To achieve this the fighter should aim to strike the target at around 80% of the arms extension where velocity is highest and follow through with the movement of the punch

(Djurdjevic 2008)

 

It can be noted that the use of boxing gloves has an effect on the impulse momentum relationship as the compressing of the glove causes the momentum to be transferred more slowly to the target reducing the force of the strike when compared to a bare fist, also the glove dissipates energy due to the coefficient of restitution of the glove, protecting the hand from injury. From a technique perspective the fighter should try to hit using the two largest knuckles of the fist, not only because they are stronger but also to create a smaller area of impact and transfer of momentum into the target. (Blazevich 2010)

Viewing this video of a boxer hitting a heavy bag in slow motion you can view the principles of his force production as well as the transfer of momentum into the target and the opposing forces of the collision. 

The Answer

So to answer the initial question of ‘How do Muay Thai boxers achieve maximum power from a straight punch to increase their ability of a knockout?’ we need to review and combine the biomechanical principles that have been outlined. Force production being the first stage of creating the momentum needed for a ‘powerful’ punch comes from a summation of forces along a kinetic chain, starting from the feet pushing from the ground, the hips and shoulder rotating and the arm extending to create a throw like movement pattern that results in a high velocity of the fist. Conservation of angular momentum and muscle tendon elasticity in the arm assist in creating this high velocity movement by balancing opposing forces and adding extra potential energy.

The timing and connection of the fist are also equally important in terms of achieving a knockout punch. Force is not the key part of a successful punch but rather the impulse of the punches contact with its target. This needs to be at the time of highest fist velocity and should follow through the target to ensure transferring the maximum momentum. Aiming to hit with a smaller surface area of the fist will also assist in reducing the coefficient of restitution. 

How else we can use this Information 

The information provided here can be transferred to many different types and aspects of sport especially those which aim to create high momentum for either a throw or strike such as athletic field  events e.g. shot put or striking sports such as baseball. In both these types of sport the aim is to create a high amount of force in order to transfer momentum into another object. The principal of summation of forces through the kinetic chain applies in many sports in the same way, with force being produced from the ground up, from the feet and legs in combination with rotations at the hips and shoulders and flexion and extension of the limbs to create high velocity and the distal parts of the limbs or to a extra lever such as a bat.

For sports that include collisions the secondary phase of information will also prove useful. The same principles of transferring momentum to another object apply such as in the sport of baseball, where the bats momentum is transferred into the ball or in contact sports where players collide with one another, if one player applied large force over a long period to another player (presumably at a lower velocity) then if would act as a push, if the a large force is applied over a short time (at a high velocity) then the collision would become more of a ‘hit’. The coefficient of restitution applies to many other sporting areas also, in all ball sports balls with different surfaces and elasticity will have an individual cooeficient of restitution affecting the energy that remains in the object after collision. This principal also justifies much of the use of safety equiptment and padding that we see used throughout sports.

References

Blazevich, A. (2010). Sports biomechanics, the basics: Optimising human performance. A&C Black.

Walilko, T, J.,  Viano D, C, et al., (2005). Biomechanics of the head for Olympic boxer punches to the face. Br. J. Sports Med., 39, 710-719.

Mack, J., Stojsih, S., Sherman, D., Dau, N., Bir, C. (2010). Amateur boxer biomechanics and punch force. International conference on biomechanics in sport.

Djurdjevic, D. (2008). Hitting harder: physics made easy. The Way of Least Resistance: Essays on the martial arts and related disciplines. Viewed online http://dandjurdjevic.blogspot.com.au/2008/09/hitting-harder-physics-made-easy.html

McKinney, S. (2013). Biomechanics Of Throwing A Punch With The Dominant Arm. Viewed online http://articles.submityourarticle.com/biomechanics-of-throwing-a-punch-with-the-dominant-arm-312041

Slow motion heavy bag. viewed on youtube https://www.youtube.com/watch?v=kah0Fnde1ME
Muay Thai straight punch image. viewed via google http://www.muaythaiauthority.com/2010/10/wck-muay-thai-pala-results-grachev-and.html