Text Box: What is Biomechanical ?

Biomechanics is the scientific analysis of human movement-the field of science that studies the internal and external forces acting on the human body and the effects produced by these movements. It's based on kinesiology (the mechanics and anatomy of movement), which was once primarily concerned with the structure and function of the musculoskeletal system. Kinesiology, however, could not clearly describe the mechanical principles applicable to human movement, so it gradually merged with other sciences and biomechanics was born. Using biomechanics, anything can become more effective at producing force and efficient movement. Choi Kwang Do has embraced the new science of biomechanics, and believes these principles should be applied to all martial arts so we can develop techniques that are more effective for self-defense and health. The tense, rigid, lockout movements used in some martial arts are detrimental to health when performed forcefully over a period of time.


Biomechanics and Martial Arts

The primary aim of martial arts techniques is to produce force, and biomechanics can tell us if a movement is correct or incorrect. If correct, the movement produces force in the most effective manner. Here's the catch: A force generated by the human body produces an external effect on a given target, but at the same time, that force produces an internal effect on the human body.

For example, if we are interested in analyzing the motion of a man's left leg, that leg is the mechanical system. The forces acting on the system from outside (the rest of his body parts) are external to the leg’s mechanical system. However, his left foot, lower leg, knee and upper leg are all internal forces acting on the system. Identifying  mechanical systems in martial arts techniques means that the movement can be further analyzed so the external and internal forces acting on the mechanical system can he better understood.


Forms of Motion

Linear motion is the motion of a body that moves in a straight line (or in translation). In linear motion the body needs to travel in the same direction at the same time, in a straight line. A good example to grasp the concept of linear motion is a downhill skier traveling with linear motion downhill, in a tucked position in a straight section of a course.

This type of isolated motion seldom occurs in complex movements such as martial arts techniques. Angular motion occurs when a body is in rotation and moves in a circular manner. A good example of a body in rotation is the trunk rotational exercises in the, warm-up section of this book. The vertebrae acts as an internal axis of rotation and the outer body move about a circular angular path.



To understand the biomechanics of martial arts techniques, we must also understand kinematics, the branch of mechanics concerned with motion without reference to force or mass. The combination of linear and angular motion is called general motion, which is the motion used in almost all human movements. Concepts from kinematics, when applied to linear and angular motion, enable us to understand martial arts techniques and recognize that Choi Kwang Do's techniques are ideal movement.


Distance and displacement describe the amount of a body's motion. Distance is simply the length of the path that the body travels. Displacement is the measurement from the body's initial position and its final position. But the displacement depends on the type of the body's motion.


Speed is the rate at which the body or a part thereof moves from one location to another. The average speed is calculated by dividing the distance covered by the time taken. Velocity measures a body's motion in a given direction, calculated by dividing the displacement by the time taken.


Acceleration is the rate of Increased velocity. (Because of gravity, all parts of the body constantly experience a slight downward acceleration.) The acceleration of an object is directly proportional to the size of the force causing it. In other words, the greater the force applied to an object, the more acceleration will result. This is especially relevant to smaller objects.

2. The transverse plane is created by a horizontal line that runs across the other two planes, dividing the body into upper and lower halves. Transverse plane motion is found in CKD techniques such as swing kick, reverse swing kick, crescent kick, twisting kick, round punches and diagonal punches.


3. The frontal plane is created by a line from ear to ear down the middle of the body, creating a front and a rear. Frontal plane motion is found in the side kick. Movement it, described (if it is actually along the plane or parallel to it) in that specific plane of motion. Movement can occur predominantly in one plane, but no motion/movement occurs in only one plane of motion. Multiplanar motion is required for all our daily and recreational activities. The kinetic link works synergistically, using acceleration, deceleration and stabilization in all three planes of motion.

Frontal and sagitlal movements (such as front kick or side kick) are impractical for kicking face level. Although a flexible individual may touch a target at this height, they can't produce enough power for a self-defense situation. This is easy to understand if you try it with a target such as a wall or bag.

Biomechanics also uses anatomical terminology to describe locations/positions on the body:


· Superior means in a higher position or above a reference point.

· Inferior means below or lower than a reference point.

· Ventral or anterior refer to a position toward or at the front of the body.

· Medial refers to a point near the midline of the body.

· Lateral (the opposite of medial) refers to a point toward the outside of the

body or  farther away from the midline.

 Proximal refers to a point nearer the origin of a structure (center of body).

 Distal refers to a point farther from the origin of a structure.

 Posterior or dorsal refer to a position toward or nearer the back of the body.

 Contralateral refers to a point on the opposite side of the body.

 Ipsilateral refers to a point on the same side of the body.

Conrtralatcral and Ipsilateral Movements


The brain is made up of two hemi­spheres connected by a bundle of nerve fibers (the corpus callosum) in the middle. The left hemisphere controls the right side of the body, and the right hemisphere controls the left side. The left hemisphere is usually the logic hemisphere, dealing with precise details, pieces, techniques, etc. The right hemisphere is usually the gestalt hemisphere and deals with the whole picture, images and emotions. However, in some rare cases, the hemispheres can switch processing roles. The corpus callosum allows the hemispheres to communicate as a complete unit. When they are communicating well, we have calm, integrated thought and an optimal learning state called whole-brain thinking.

Sequential Motion

A sequential motion uses all of the individual segments of the kinetic link (human body) to generate momentum, and can therefore produce greater levels of force!

All Choi Kwang Do techniques use sequential movement. When we perform the CKD rear inward punch, for instance, the hip and thigh move ahead of the trunk with plantarflexion.


A pushing or pulling motion uses the segments of the body simultaneously to produce force, but a motion that uses sequential motion transfers momentum from one segment of the body to another; from the larger proximal segments to the smaller distal segments, until the momentum is delivered to the last segment in the link. Then the trunk moves ahead of the shoulder, which moves ahead of the arm. Finally the arm extends to deliver the punch. In force-production capability. If a muscle is stretched (lengthened) beyond a certain point, it will contract (shorten) forcefully, much as when we create tension in a rubber band by stretching it and letting it go quickly (plyometrics principle). Because of the chain of events in the CKD sequential movement, stretch reflex  is involved In force-production capability.

That's why it's essential that martial arts use biomechanics-because practitioners can receive serious joint tissue damage and injury from a biomechanically incorrect technique!


The task of biomechanics is to define the mechanical system of the body. The task of martial arts training is to analyze the motions of our techniques. We can create the most effective techniques by analyzing all parts of the body as mechanical systems.

Deceleration or negative acceleration, is the slowing down of velocity. For example, swing kick performed in the air start from a point of zero velocity and then undergoes positive acceleration until it passes the target position. At this point, deceleration allows the technique to slow down and finish naturally. (At Choi Kwang Do, we don't perform any technique that locks out and stops suddenly, because it would be stressful on the joints and body.)


1. The sagittal plane is created by a line running exactly down the midline to create equal left and right halves. Sagittal plane motion is found in CKD techniques such as front kick, front heel kick, downward kick and upward punch.

When one hemisphere is processing information more predominantly than the other, it's vexing

to the brain and our thinking is negatively impacted. How we move also dramatically affects the

brain. Exercise can either stimulate or strain the psyche.


Contralateral (or bilateral) movement is natural movement using opposite body sides. When we walk, we swing the opposite hand to our foot. This spontaneous movement stimulates our brain.


Ipsilateral (or homolateral) movement is simultaneously using a hand and foot on the same side of the body. This movement is prevalent in many sports activities such as fencing, bike riding and tennis. Ipsilateral movement is also found in many martial arts systems. For example, the technique right uses the left hand to block, and body weight is predominantly on the left foot.

Some scientists have found that continual and prolonged ipsilateral movement can overstress the brain and even temporarily shut down communication between the hemispheres by "switching off" the corpus callosum. This limits integrated thought and lowers energy level.


Extended use of these awkward movements can also hinder learning, because it can overstress, or even permanently damage, the hippocampus (a complex neural structure, shaped like a sea horse, that has a central role in the formation of memories). Sometimes slightly elevated stress is good for our memory, but ongoing and/or excessive stress is detrimental to learning.


Certain Choi Kwang Do techniques are, in fact, ipsilateral, but the stress is neutralized because of the way we maneuver. In the front inward punch, for example, we use the rear hand (left) to guard the left side of the face while we shift our body weight into a right front dynamic stance. This is a contralateral movement. From there, because we use sequential motion, the punch is delivered a split second after the weight shift, which counteracts the akward ipsilateral movement.


Choi Kwang Do teaches predominantly contralateral movements-using the hand and foot on opposite sides of the body.

We normally use contralateral movements when we crawl and walk, too, and this natural movement stimulates our brain.

(The early process of crawling is essential for creating neural links between the left and right hemispheres.)

Kinesiologists claim that integrated movements can dramatically improve learning capability in people of any age. CKD movements stimulate the brain naturally, without stress. The contralateral technique right uses the right hand to block, with body weight predominantly on the left foot.


Choi Kwang Do movements, especially our patterns, can develop  the nerve fibers of the corpus callosum

by providing each side of the brain with specific functions. This could help people develop a more balanced,

integrated way of thinking and process information less stressfully, quicker and more efficiently.

If a muscle is stretched (lengthened) beyond a certain point, it will contract (shorten) forcefully, much as when we create tension in a rubber band by stretching it and letting it go quickly (plyometrics principle). Before we deliver a CKD punch, the stretched shoulder muscle will contract like a rubber band. All CKD techniques take full advantage of  stretch reflex to produce maximum force.


Incorrect patterns (not using sequential movement) in martial arts techniques means that the production of force will not he transmitted in the most effective manner, both externally on a target and internally on the kinetic chain. Poor movement patterns can cause unnecessary stress on bones, joints and muscles because the force is not absorbed or distributed in the most efficient way. This also increases chances of injury. When movement patterns are biomechanically correct, as they are in Choi Kwang Do, stress is minimized, so joints can strengthen and become stronger, and power can be maximized.

CKD Improper Sequential Movement

CKD Proper Sequential Movement

Optimum Health - Fitness - Self Defense