All of the movements and events involved in the performance of Martial Arts can be described by the science of Physics. Because the science of Physics covers a larger amount of information it is broken up into smaller more specialized sections or branches. The branch of Physics most useful in explaining and understanding the Martial Arts is called “Mechanics”, which is defined as follows:
“Mechanics is the branch of physics concerned with the behavior of physical bodies when subjected to forces or displacements, and the subsequent effects of the bodies on their environment”.
Mechanics can be used to describe Martial Arts because a human body fits the definition of “a physical body”, and the movements and events involved in Martial Arts subject the body to forces and displacements.
Mechanics itself is can be divided into different areas or branches. The examples found in this particular blog entry come from the branch of Mechanics called “Statics”, which is defined as follows.
“Statics is the branch of mechanics concerned with the analysis of loads (force, torque/moment) on physical systems in static equilibrium, that is, in a state where the relative positions of subsystems do not vary over time, or where components and structures are at a constant velocity.”
Statics employs Trigonometry to analyze the forces acting on an object. Trigonometry is
“the study of the relationships between the sides of a triangle and the angles between those sides”.
The picture below shows two simple physics problems that are meant to be solved using Trigonometry.
Each problem shows an arrow drawn on a two dimensional graph. The arrow is called a “vector”. Vectors are used to represent forces. The number associated with each vector indicates how strong or powerful the force is, and the value of the angle indicates the direction of the force relative to the X axis.
A force can be broken up into it’s components. The F(X) and F(Y) notations on the previous example problems,
denote the force component in the X direction and the force component in the Y direction respectively. The components forces are calculated using the strength of the force, the angle of the force relative to the X axis, and Trigonometry.
The next two pictures demonstrate how statics is used to solve real world problems.
The next picture shows two more physics problems asking the student to determine the component forces of a given vector. Please pay special attention to the second problem will be used to demonstrate how statics can be applied to an example body movement used in many Martial Arts.
Both of these examples show the force going downwards. These downwards forces resemble the leg of a person who is kicking to attack or block.
The kicking leg of the man is oriented in the same way as the bottom physics example problem.
All that needs to be done is to add the X and Y axes, the angle of the leg to the X axis, and the force of the kick for the real life kicking example to look just like the classroom physics problem.
The picture above shows how physics knowledge is used to break down the force in an arm or a leg into it’s components. After you know what the components of the force are, you can then calculate what force is needed to counter the incoming force. The calculations will tell you the exact angle and amount of force you need to block the incoming force.
An example of this process can be demonstrated with the following picture, which show the computer model holding it’s right arm in what is called a “Low Tan Sau”.
The angle between the shoulder, the elbow, and the tips of the fingers of a Low Tan Sau each have a certain value. The triangle is duplicated on the right so that the angles can be seen more easily.
The next picture shows the model performing a High Tan Sau. The Tan Sau had to reach higher and extend outwards more to reach it’s current location.
The triangle for the High Tan Sau is obviously different than the triangle for the Low Tan Sau.
Triangles are mathematically described in terms of their angles. ( Arbitrary values were assigned to each angle in the following picture. )
The results for the physics calculations for each of these triangles would be different. Each triangle is a good triangle for deflecting a force that is coming in at one particular angle.
The process above applies to many of the movements in most all martial arts. The process applies to the arms, the legs, the head and the torso.
A simple and useful way to look at how these triangles affect your own body is the concept of balance. The triangle below would be a balanced triangle. All three angles of the triangle have the same value of sixty degrees.
The total of the angles of a triangle, if the shape of the triangle changes, the overall number is still the same. The number 180 will still be at the top. Because the triangle is unbalanced, the other numbers on the side will change. Whatever they change to, they must add up to 180.
The number 180 is still at the top of each triangle in the picture above. The triangles are of an entirely different shape than the balanced triangle above. The numbers on either side are now different from each other.
This process happens continuously as a human being moves their body. When a person performs the Sil Lum Tao form, the arm moves from Low Tan Sau to High Tan Sau. If the example above had a moving digital display, we could watch the numbers on either side of the triangle change as the arm moves.
The purpose behind knowing all of this is to answer the question why? When you ask your teacher why a movement is performed a certain way, the most common reply is “because that is the way it is done”. If you understand the concepts here, you can apply it to any martial arts movement to determine where the forces are going. Once you know where the forces are going, you will understand why the movement is performed the way it is.