Science and Golf
Science has actually contributed very little to the discoveries made in
golf. It usually only confirms what has been proven through the endless
trial and error experimentation that takes place every day on golf courses
throughout the world. The greatest contribution of science has been in the
refinement of innovations after a scientific analysis has shown that it
works and why.
Thousands of subtle muscle movements are involved in a golf swing that
takes a little less than a second from start to finish and a collision
that is completed in 0.0005 seconds. All of these movements are to be
learned in motor memory and required to perform in the right sequential
order with precise timing.
Science has shown that if the clubface is ½ degree less than square to the
ball, the ball can go off course by 20 yards. Additionally, if the
downswing is the slightest bit curved, the ball can slice 30 yards off
course and travel a much shorter distance. Furthermore, a difference in
velocity could mean a ball landing a few feet from the hole or rolling off
the green, a change as much as from 110 miles an hour to 111 miles an
hour. Finally, if the ball is struck ¼” too high, it will weakly dribble
its way into the fairway whereas striking it ¼” to low will shoot the ball
up to the sky landing the ball short of the target.
Weather consideration has to be taken into account. If one is expecting to
adjust a shot for a 20 mile an hour headwind that mistakenly turns out to
be a 30 mile an hour headwind, a 120-yard approach shot will drop 20 yards
in front of the green instead of at the pin. Characteristically, golfers
use a lower trajectory shot that is less affected by high winds than the
high arching shot, the tradeoff is that the lower trajectory/higher
velocity shot will have more difficulty to stop as quickly.
Golfers are of all ages and the golfer’s game changes in relationship to
flexibility, strength and mental sharpness. The bone continues to grow
until the late teens or early 20s with the greatest width and density peak
occurring at the age of the 30-35, and from then on, the bone density
starts to decline. Posture is continuously changing due to gravity. With bad posture,
biomechanics change as do swing dynamics.
Science and physics of the perfect swing has been a challenge for golf
athletes, instructors and investigators. Although computerized models of
physics, velocity, levers, momentum, distance, speed, range of motion and
flexibility have been calculated, it has become difficult to apply
this information to every individual. The reason for this is that everyone
possesses unique physical characteristics (height, weight and body frame;
as well as differing athletic skills such as speed, quickness, strength,
flexibility) making these unique differences difficult to take into under one
Science has always focused on the power of the swing using a formula where
power equals force times velocity. Power for golfers has a different role
than for professional weightlifters. Powerlifters use strong ballistic
movements to generate an explosive velocity from all of the muscle groups
acting simultaneously. The golfer generates power through sequential
movement of force through the larger muscle groups into the smaller
muscles and an accelerated motion in order to gain the highest club-head
speed at the moment of impact. Golfers have to sequence muscles contacting
and relaxing almost fluidly in order to prevent them from interfering with
the acceleration process.
Golf has been studied on the basis of physics trying to determine how much
power or energy is required. Power is defined by work done over a period
of time. A physicist, Ted Jorgensen the author of The Physics of Golf,
calculated that 32 pounds of muscle needs to be generated for a typical
professional golfer’s swing to deliver two horsepower of energy.
Calculating large and small muscle groups, he reasoned that the 32 pounds
of muscle force cannot be exclusively generated by the arms and shoulders
whereas he found that most of the power had to come from the legs,
buttocks, back and abdomen.
The golf swing power is a fine-tuned control of muscle contraction and
relaxation where a seamless transition from backswing to downswing
maintaining the transfer of momentum from one muscle group to the next.
This is an extremely difficult task to master and more so to encode in
The mechanics of the backswing and downswing prepare the golfer’s club to
strike the ball at impact with the clubface square with the highest energy
transfer or velocity. The dynamics of the collision are explained in terms
of energy or momentum. Momentum is defined as mass times velocity. Optimal
momentum and energy transfer come from proper linear and angular
Using the example of a boxer striking an object, they find that striking through the object to a
point further in allows them to achieve the highest momentum and energy to
accomplish their action. One reason amateur golfers have vastly different
collision dynamics is that they may not have developed the skill to strike
through the ball. At the moment the clubface strikes the ball, only a
small fraction of energy is transferred to the ball as the club-head, after
impact, decelerates from an average of 100 miles an hour to 90 miles an
hour. This collision lasts approximately 0.0005 seconds, which is a very
short time frame for transfer of energy and momentum.
Physics has always modeled the golf swing to a double pendulum or a
two-lever action. One lever is formed by the shoulders, arms and wrists
rotating in the upper chest. The second lever is the club rotating through
the wrist cocked and un-cocked. Coordinating the timing of these two levers
is one of the most difficult things to teach and learn.
The golfer’s downswing has been analyzed and has found that the action of
the left arm is critical. The pull of the left arm provides the
acceleration relative to the shoulder joint. The left arm should pull the
golf club and body toward the ball. Then, as the left shoulder slows, the
hips and legs push the body and club toward the ball. This combination of
movements is usually quite unnatural and difficult to teach to the
The momentum achieved through the downswing provides an energy
momentum transfer that generates a club-head velocity. This
club-head velocity at impact is the key. Those golfers that have a
well-timed fluid transfer of energy or momentum achieve the highest
possible club-head velocity at impact. Tiger Woods describes his explosive
swing focus on that his legs and hips drive forward, whereas, his upper body
simply unwinds. He described this momentum transfer process in the
framework that the lower body starts the whip action, the legs and hips
drive forward delivering linear momentum, and the upper body unwinds
delivering angular momentum.
Speed and acceleration are two separate and important concepts. Speed or
velocity is a reference of distance over a period of time.
Acceleration is a changing increasing speed, not constant.
Acceleration is the key point of impact that allows for maximal ball
The example for continued acceleration is demonstrated with Mark McGwire
in baseball. He did not have the fastest bat speed, however he did have
the greatest velocity immediately after the ball was hit. McGwire had
continued acceleration with great muscle mass that resulted in more
momentum being transferred to the ball.
Kinesiologists, scientists who study the body movement and mechanics, have
demonstrated that poor mechanics prevent golfers from achieving a smooth
constant acceleration. Studies show that most recreational golfers reach a
top speed of acceleration too soon and, as a result, the club-head actually
starts to slow down right before contact.
Kinesiologists through body mechanics have found that precision timing of
hundreds of muscle contracting and relaxing in a proper sequence is
critical to promoting acceleration. Observing an athlete with jerky swing
motion often represents a problem of muscles fighting each other or
co-contracting causing deceleration.
Acceleration although important to optimize the power of the swing can
also be a detriment at the expense of accuracy.
As one tries to achieve optimal acceleration, muscles are asked to exert
maximal power in a very short time which results in rushing the shot,
overstretching the muscles, difficulty in maintaining proper motor
learning of timing as may lead to balance problems. The key to a
powerful golf swing is to promote as much force as possible within an
accuracy of striking the sweet spot, the zone of highest energy transfer.
Miss-hitting the sweet spot creates a significant error in ball flight
Maintaining balance is critical in the transfer of weight from the
backswing to the downswing. Most golfers are under the impression that the
weight shift occurs from the left foot to the right foot during the
backswing and returns from the right foot to the left foot in the
downswing. This actually is a misnomer. What should happen is that the
right leg should shift its weight from the toe to the heel in the
backswing and, to a lesser degree, from the heel to the toe of the left
During the downswing, the weight is redistributed primarily in the left
foot from the toe to the heel and, to a lesser extent, the heel to the toe
of the right foot. For this to occur, the hips, back and the shoulder must
rotate into toward the leading side. At the end of the downswing, the
majority of the weight should be distributed into the left heel.
Executing this proper weight shift move, increases the club-head/ball
impact speed by 14.4%. This 14.4% improvement changes a drive that would
normally travel 200 yards to travel 229 yards.
The Cause of Spring-loading
The backswing is more important than the downswing to achieve stored
energy or spring-loading. The backswing incorporates the properly executed
wrist cock, weight shift and rotational action. When the backswing is
executed properly, the downswing will occur almost naturally. The key
should be for one to practice the
development of a smooth rhythmic transition from backswing to downswing.
Cocking and Un-cocking
The wrist action is very complex. In golf the wrist has two primary actions:
cocking and un-cocking.
Studies were done by Jorgensen to analyze various wrist-cocked angles of
90, 110 and 130 degrees. The findings showed that the larger the wrist
cock angle just prior to the downswing generates the greatest swing
velocity. This, of course, assumes good flexibility such that the wrist
cocking motion is natural and comfortable. If the wrist cock angle is not
natural or exaggerated, it will be difficult to maintain a good swing tempo.
Physicist Alastair Cochran, the author of
Search for the Perfect Swing,
found that, as the shoulders and arms are still moving upward to the top
of the backswing, the hips actually begin moving forward approximately 0.1
seconds before the club-head reaches its furthest backswing position. This furthest
position is the point of greatest coiling power. This principle of the
body moving forward as the club is moving backward dramatically improves
the ability to store and release this elastic energy. One can visualize
this concept in the motion of trying to snap a towel by starting its
movement forward and just prior to the towel going all the way back.
Once one masters the backswing skill of cocking, then comes the downswing
and un-cocking. Un-cocking is the pushing down with the back and wrists
through the downswing. As velocity increases during the downswing, there
is a natural tendency to un-cock early due to the increasing pull or torque
of the wrist. At the start of the downswing, one feels only 15-20 pounds
of pull from the club; however, as one completes the downswing near ball
contact with the club moving 80-100 miles per hour, this torque is
increased to 70-90 pounds. This significant increase in torque being
four-fold encourages the forearm muscles of letting the wrists go and conscious
effort should be made in order not to release the
The goal of the golf swing is to efficiently utilize the muscles for peak
performance. Amateurs have been found to grip their clubs much more
tightly than professionals. Studies of grip strengths show that
professionals exert about 25% of the maximal force in their grips, whereas
amateurs grips are much higher, up to three times as tight.
Unfortunately, having a very firm grip contracts in the wrists, forearms
and upper arms, which reduces the fluidity of energy transfer from
backswing to downswing. Tight grips have been found to reduce
velocity which compromise control and accuracy.
Athletes build their muscle and motor memory from input. Basketball
players play with the ball bouncing and rotating in their fingers before
shooting a free throw to sharpen the sensitivity in their fingertip nerve
endings. Professional golfers employ a similar technique.
Professional golfers roll their hands around the grip before settling on
the final hold in order to activate their sensorium. By maintaining
a relaxed grip, they continue this sensory communication between their
fingertips and the brain, which promotes more effective feedback, as well
as provide a more consistent pre-swing visualization.
Sam Snead was quoted that the lighter the grip at the top of the
backswing, the greater the muscles in the arm stretch and the farther and
faster they can contract, thus, accelerating the swing more effectively.
Swing length has been discussed with the thought that the longer the
swing, the greater the force exerted on the club. Unfortunately,
studies found that the extra time and distance of the backswing results in
only very marginal increases in club-head velocity at impact at best.
Although this is contrary to
most instructors and golfing books that claim that every shot, especially
the misses or missed shots, should be mentally processed.
The key to successful practice
that promotes proper motor learning of muscle memory, is to only
emotionally remember successfully achieved mechanics. Avoid any
negative emotional response for a misplayed shot in your golf swing.
Visualization starts the motor
learning as it sensitizes the brain preparing it for the complex movements
of muscles for the golf swing. As motor learning and visualization
become more engrained, one becomes more natural in the process. With
the positively charged emotional response to this motor learning, one
approaches to what athletes call "the zone". "The zone" is having
the confidence and the relaxation of the brain and its learned muscle
memory perform the skill that you ask of it without any distractions that
may disrupt their automatic movement.
Due to the excellent training, physical conditioning, flexibility and
understanding mechanics in sports, athletes have become fairly equally
matched in their physical skills. In one-on-one
primary determinant for winning in equally matched physical ability is
found on the basis of the mental confidence that is one player has
confidence that he will beat his opponent.
In confidence, the greatest threat is second-guessing or last-second
changes in the preparation for the shot. Last-second changes create
confusion for the nervous system and the brain, which ultimately changes
the timing, mechanics and fluidity of the action.
“The Zone” can be explained as nothing more than the relaxed state of
concentration and heightened confidence. Golfers experience a dual sense
of a heightened level of mental concentration, yet a very relaxed muscle
state. In “the zone”, golfers mention the feeling that the complex
athletic movements were performed automatically. Comments such as
“everything feels smooth”, “your senses become sharper”, “you see all
things clearly”, “you can see the light of every putt” become familiar to
those who have been in “the zone”.
Four Things to Avoid
Do not over practice.
Practice should be approached to strict concentration in order to cement a
muscle memory with positiveness and without major adjustments. The brain will
encode this action. As one finesses their swing, a better synchronization of
brain activity occurs and tighter brain maps become improving the confidence
Practice for the golfer should be limited to no longer than half an hour.
Greater than half an hour creates decreased concentration, alertness,
distraction thereby creating confusion for the brain.
Equally important is to
focus on one aspect of the golf game for that half hour incorporating minor
adjustments. An example would be performing short chips
from the fringe of the green on an uphill slope to the cup, practicing
from deeper and shorter grasses with slightly different distances;
however, the primary focus would be chip shots. The goal is to encode a
muscle memory for this type of shot while only incorporating the positive
outcome of the best strokes.
Do not over rely on your eyes.
People over rely on their
eyes. An excellent way to improve motor memory is to practice with your
In putting, practice
from the same distance until you drop three in a row. Now, close your eyes
and try the same putt but do not open your eyes until you think the ball
is within inches of the cup. This drill improves other sensory input such
as listening to the ping of the contact, noticing the feel of the speed of
the pendulum motion of you arms as well as the feel of the fingertips at
the point of contact, especially in the sweet spot.
Do not over focus.
When approaching a
swing, do not overly focus on the ball until you are set and ready to
Focusing too early and too intensely will diminish the ability of the eye
to center on the golf ball.
Do not over think.
Allowing practice to
incorporate proper motor memory, the movements should become automatic and
reflexive. The golf swing for a professional is as natural as is walking
for the general population. They do not put any conscious step-by-step
thinking into swinging a golf club, as we do not dwell on the mechanics of
walking. Over-thinking leads to second-guessing, which erodes confidence.
Should you have any further questions
regarding this article, please direct your questions or comments to "Ask
the Doctor" section.
Copyright © 2004 - 2012Taras V.
Kochno, M.D. All Rights Reserved
Board Certified in
Physical Medicine and Rehabilitation