Golf Science    

Home     Free Lessons    Training Aid Products     Links

Four disciplines make up the body of human performance science ...
 bio mechanics, kinesiology, motor learning and sports psychology

Biomechanics ... a simple way to understand this field is to compare how the bones and the muscles act to create a lever system that works in much the same way as a construction crane.  Muscles only shorten or lengthen.  When this happens, bones move.  Bones don't go just anywhere.  They are forced to move in the direction of the muscle acting on the bone and on the direction the joint allows the bone to move.  If we put our bodies in certain positions we can move with more speed, power and accuracy.  If we get into a less favorable position we slow down, are weaker and less accurate.  
To a golfer, this means there are "correct" things you can do to create speed, accuracy and power and there are "wrong" things you can do to make things go wrong.  Putting your body in a bio-mechanically efficient posture at address creates the possibility for a "natural", "free-flowing" swing motion.  The word natural can be closely related to the idea of not having to "try".  Believe it or not, it's much easier to make a good swing than it is to make a bad swing.  

The concept of a swing in itself may be the first step in a lot of wrong thinking about golf.  The swing is really more of a rotation driven "sling" than a swing.  The golf swing operates off the 1st principles of physics regarding force production.  A lot of golf biomechanics is related to the laws of levers ... like the teeter totter.  The golf swing has both a horizontal and vertical component.  When these two planes are combined the swing revolves around an inclined plane.  Think of a merry go round being like a baseball swing.  When it turns on it's side, it more like a who knows what and when it is tilted only about 45°, it starts to look more like a golf swing.  The center axis is the key.  In the human body, this axis is your spine.  The deck plate of the merry go round is similar to your two collarbones. 

The general area of the intersection of the spine and the two collarbones is the center of your swing or sling motion ... if it moves, then the outside edge of the deck plate (the swing path the clubhead follows) also moves.  The first lesson in golf is to keep your eye on the ball.  This is NOT the same thing as keeping your head still.  It seems the human system is not about equal opportunity.  It cannot easily handle vertical movement of the swing center, but it can handle horizontal movement.

The human machine works like a construction crane.  The crane has a motor to produce force.  That force acts on a resistance through a pivot point.  The letters F, A and R are used to designate where the force is applied, the axis which controls the direction of the movement.  The human body has the same components a motor, a string line and the structural frame.  Muscles are the both motor delivering force through a joint which acting on the resistance of your arms and the string line connecting the parts of the system.


  • The golf swing is powered by a rotational motion of the body.  The muscles and bones of the torso act as a wheel and axle to change the direction of the movement and to increase the speed of the movement.

  • The movement of the torso spreads outward to the arms and further on to the club.  This works as a kinetic chain where the movement of the previous link in the chain passes its energy.  This plain speak ... the golf swing works best when it moves from the inside to the outside.  Each passage of speed/energy adds up.  In physics terms this is called the summation of segmental velocities.  Think of a fishing rod as it sends enough energy to cast a lure great distances.

  • Most joints are 3rd class levers and work as a wheel and axel, like a pulley … they change the direction of the applied force and increase distance and speed of the second lever arm (rib cage)


  • The body and the arms form two separate, but connected bio-mechanical lever systems … the torso and the arm/shaft

  • The arm and club system magnify the force created by the rotation of the trunk much like how a fishing rod whips a lure great distances

  • The golf swing is more properly described as a “sling” … it is critical to understand the force being applied to the arms and passed to the club is due to the rotation of the body.  Think of a little Oriental drum toy.  As you twist the stem, the strings fly outward.  The difference between the toy and you body is your body doesn't have limp "spaghetti arms".  The muscles of the arms provide additional stability to the movement.  They do not produce much force, the the role of stabilizers cannot me understated.  Now, motor learning science is producing new knowledge that there is the potential to actually correct last instant swing flaws.  How we might use this new information is very, very slowly emerging.

  • The lever system for the legs is of no major consequence because the muscles of the legs are generally inactive …the role of the legs is to provide stability and support the to body and arms.

  • Another shocker is it is ineffective to "hit" with the hands.

  • An even greater shocker is the clubhead slows down in the last instance before impact.  This flies directly in the face of traditional concept of "hitting through the ball".

In the left hand image, the distance the club moves in each strobe increment indicates how fast the club is moving.  The distance for the "pre-impact" section is larger than in the final instance before impact.  The handle of the club is your only point of control over the clubhead.  The clubhead goes nowhere the handle has not gone before.  How you handle the handle determines where the ball will go!

There is a huge fraud being perpetuated on golfers

  • Golf gurus and teaching pros continue to use a two lever model to describe the golf swing.  Even a superficial look at the human system shows at least four levers in just one arm (collarbone, upper arm, forearm and hand.  Since most golfers use both arms and hands to connect to the golf club, we can double that number of levers.  Even though the muscles of the arm are providing stability more than force production. they still have mass and gravity is still a force so both arms must be considered.

  • A completely overlooked swing dynamic is the existence of a "force couple" between the top and bottom hands.  This is NOT the same thing as saying you try to "hit" through the ball at impact.  It is an acknowledgement that both the left and right arms are applying force to the handle.  The top hand slows as it approaches impact.  The bottom hand continues to accelerate.  The small, but important distance between the center of each hand is critically important to understand.

  • A far more accurate model is the seven lever model which accounts for two hands being on the club and two arms slinging around the rotation of the trunk.  This is this dramatically extends the complexity of a mathematical analysis. 

  • A two lever model is OK for describing the forces on the shaft, but it is totally inadequate to explain the forces being applied by a human golfer.


  • Most golfers never take time to consider … muscles move you and the club.  Understanding how muscles work is important … muscles work on bones and joints.  Muscles can only pull, (flex) they can never push

  • Muscles have an origin and insertion (start and end) points which determine what type of leverage/movement they can make.  Considering the bicep ... the origin is near the shoulder and the insertion is just below the elbow.  This is a F A R relationship which a relatively large amount of force is needed to produce movement of the forearm.  The mechanical advantage is in the form of increased speed.

  • Knowing the shape and structure of the joint will tell you what kind of movement the joint can be make.  The shoulder joint is a ball and socket joint capable of movement in any direction.  The wrist joint is also capable of multidirectional movement, but it takes eight bones to accomplish what a socket joint can do.

  • Most joints are the axis in a third class levers.  Most human movement is F A R, wheel and axel

  • The primary function of the arm muscles is to provide stability and small, subconscious corrections in support of the inertial/centrifugal forces created by the rotation

  • A third class lever … multiplying the speed and distance of the end of the system The 3rd class lever system is the most common type of lever system in the body.

In the body, an example of a 3rd class lever is the action of the biceps muscle (force generator) pulling on the forearm (lever) to flex the elbow (fulcrum) and elevate the hand (resistance).

Kinesiology ... how the human string lines, motors and control box allows the machine to learn and perform.  Almost all golfers have zero reason to know any of this bio-tekie stuff.  It is sufficient to know movement is a controlled event.

Add the physiology of the human muscular and nervous system to the biomechanical work of the bones and muscles to understand the general idea of kinesiology.  Generally, kinesiology is the more complete understanding of  biomechanical problems about "how it works".  Questions such as "What can I do to get stronger, faster or more skilled?" can be answered. 

The force a muscle produces is relative to the muscle's cross sectional area AND the number of muscle fibers recruited for the required task.  A muscle fires “all or nothing”.  To control the force and direction of movement, muscle bundles recruit the number of fibers needed to control the movement.  Other opposing or antagonist muscles are used to slow and refine the movement.

The image on the right shows how a knee jerk reflex works.  The word jerk and golf do not typically go in the same sentence.  The swing motion needs to be smooth and controlled and an all out, uncontrolled movement won't work . A doctor's hammer striking your patellar tendon is pretty different than what stimulates you to trigger your golf swing ... but wait, there's more.  It seems there' more than one kind of jerk or reflex response.  Some of these "jerks" happen a lot slower than others.  And it seems, this delayed response can be anticipated and partly trained.

All this means is the old idea of not being able to influence the downswing once it has started is not true.  How you go about taming this new beast is a completely unknown matter.



Back to the crane model ... a crane also has an operator's control box.  So does the human machine.  Knowing how the human nervous system works is the beginning of understanding learning and performance

Motor Learning ... this is the science of practice and establishing the necessary conditions for both learning and performance.  There are laws that dictate how we should practice.  Sometimes practice can be more destructive than constructive.  Yes, sometimes it's better to go home and pop a cold one rather than beating more balls on the driving range.  Motor learning teaches coaches and instructors how to maximize the learning for "individual athletes".  Because all golfers are ultimately their own coach, it only makes sense to "know the rules".  A lot of time, effort and frustration can be saved.  It has been said that all learning is trial and error.  This is obviously true for golf.  In fact, mistakes are absolutely necessary for learning.  You can't know "right" without also knowing "wrong".  Nothing, except ignorance, forces you stay at the same skill level or to constantly make big mistakes.  The general benefit of following a few laws of motor learning is that you can systematically reduce both the number and size of your mistakes.


The blue pathway (upper left graphic) shows how a reflex works.  Until recently, reflexes were thought to be "dumb", all or none movements that could be neither controlled nor learned.  It turns out some reflexes may be beneficial to your game ... if you know how to use them.  The purple and green path represents a planned, controlled movement that has been processed by the brain and sent out to a working muscle.  The work reflex has always implied an uncontrolled movement ... a jerk (as in knee jerk reflex).  But as the TV commercial says ... "but wait, there's more"!  Long latency reflexes have a limited ability to be trained and make small adjustments at the last minute before impact.  The idea that you cannot control the clubface on the downswing because the movement is faster than the nerve conduction is being challenged.  Now it is a matter of learning how to teach this valuable ability.

For controlled "muscle memory " movement, nerves send sensory signals to the brain, that position, direction and speed information is processed in several areas of the brain and then integrated into instructions going to the muscles what will be doing the work.  It is critical to understand that for every working muscle, there is an opposite, antagonistic muscle that must be relaxed.  Information is transmitted to the brain through Golgi tendon organs and muscle spindles.  This is how the brain knows where the parts of your body are located, which direction they are moving.  Those signals going to the spine and then back out to a muscle are called reflexes.

Learning Precedes Skilled Performance

  • The backswing and transition are under the control of a motor program and can be modified by cognitive effort coming from various feedback mechanisms

  • The downswing from the top can be subconsciously corrected down to the release point

  • Providing very specific feel oriented instruction strengthens the reference and comparison aspects of the swing motion

  • Practicing for specific “feel checkpoints” can be productive practice


" A Picture of Muscle Memory and Controlled Movement"

This chart shows many important motor learning concepts related to how controlled movement is developed.

  • Before movement begins three things happen ... stimulus identification, response selection and response programming.  Stimulus identification is largely visual.  This tells the brain which program to use.  Things get a little sticky here.  One, subconsciously choose from more than one response.  Think of this a choosing the right program.  Response programming is somewhat like opening a computer file and then editing it to some degree.  In this case a relatively small "edit".

  • Instructions are sent to the muscles and the brain allows movement to begin in accordance with the parameters of the selected program. 

  • Internal feedback is provided as the brain monitors the quality of the movement.  Signals come from different sources.  The first level is the muscles telling the brain their length and how much force they are generating.  The next level comes from movement  where the joint tell the brain where they are which direction they are moving.

  • The longest bath to the brain comes from the environment in the form of visual feedback.

  • The movement is completed.  A limited amount of feedback can affect performance.  Most feedback is only good for learning!





The Science of Golf Learning

Classification and Measurement of motor skills

§         Taxonomy … serial, discrete, continuous etc.

§         Error measurement … relates to which problem to fix first relative to standard performance model

§         Measuring coordination

§         Characteristics of complex skill

¨      Speed v Accuracy … obvious implications for length of the backswing, balance and timing

¨      Bimanual coordination … maxing out power with a two-sided swing

Motor Control Theories

§         Open v closed loop … is proprioception involved or not … Adams v Schmidt

§         How proprioception affects motor control

§         How vision affect motor control

Attention and Memory

§         Focus … relates to pre-swing routine and ability to switch attention from one demand to another

§         Movement and memory … the “muscle memory” thing

Stages of Learning

§         Fitts and Posner

¨      Changes across stages of learning

¨      Performance characteristics that do not change across stages

¨      Error of predicting  future achievement from initial learning

§         Adams Closed Loop Theory

Learning Motor Skills

§         Defining and Assessing

¨      Performance v learning

¨      Observational assessment … looking at performance as related to specific points of performance and statistical analysis

¨      Practice performance assessment … mechanical assessment related to variability from standard model

§         Transfer of Learning

¨      What it is and why it is important

¨      Why does positive transfer occur

¨      Bilateral transfer

Instruction and Augmented Feedback

§         Learning styles … verbal/cognitive, kinesthetic and visual

§         Demonstration and verbal instruction

§         Types of feedback, difference between FB and KR

§         Role of AF in skill acquisition

§         Timing issues related to AF

§         KR delay and post KR interval

§         Frequency schedules for AF information …

§         Techniques to reduce the need for AF

Practice Conditions

§         Blocked v variable practice … when and with whom

§         Interference effect

§         Amount and distribution of practice

¨      Learning, overlearning and mastery

¨      Massed v distributed practice; length of practice

§         Whole/Part Practice

¨      Relates to skill complexity and organization … two part or three part swing motion

¨      How to practice parts of the skill

¨      Attention and part practice

¨      Part practice within whole practice … breaking down and reassembling the swing motion

§         Mental Practice

¨      Two roles of MP

¨      MP as it aids skill acquisition

¨      MP as it aids performance

¨      Basis for MP effectiveness

¨      Imagery … visualization and kinesthetic rehearsal


    Sports Psychology ... Platform diving is about the only sport with more destructive consequences for "stinking thinking" than golf .  Don't get it, the just jump off a ten meter platform and do a belly buster.  Golf is a difficult sport because the first opponent you face is you own self.  Every time you draw back the club, you are competing against yourself before you ever compete against a golf course or opponent.  Golf brings out some of the best and  worst behavior in sports. All experienced golfers have known the frustration of working like a mule on the driving range only to fall apart like a cheap suit during competition.    

    Each discipline has contributed to what we know about golf and how it can and should be played.  Video and computer technology have become standard equipment for many teaching professionals

Home     Free Lessons    Training Aid Products     Links

Copyright © 2001  [CraftSmith Enterprises]. All rights reserved.  Revised: February 15, 2016.