2. What is Biomechanics?
Biomechanics is the study of how living things
move, and of the efficiency of movement, in
particular.
Knowing biomechanical principles can help us to
understand how our bodies move and how we can
make movement more efficient.
On the basis of such understanding, we can
develop new skills, detect errors in performance,
improve safety, and help to prevent injury, and
develop new equipment design.
3. Biomechanical Principles
It is important to have a sound knowledge of
biomechanics so that we can provide valid reasons
for observed effects, diagnose problems with
techniques, and justify changes in technique.
• Observe
• Diagnose
• Change
4. Objective of the Skill
The first in biomechanical analysis of a skill is to
state the objective of the skill,
The main purpose of a golf is to make impact on a
ball and produce power, angle, direction and
accuracy.
“The sole purpose of the golf swing is to produce a
correct repetitive impact, and the method employed is
of no significance as long as it is repetitive.” (Hardy,
2005)
The golf swing is a discrete skill, which means
it has a distinct beginning and end.
5. Movement Patterns
The next step in a biomechanical analysis is to
place the skill within the pattern of movement,
such as;
Standing, Walking, Running, Sitting, Pushing,
Throwing, Striking, Pulling, Jumping and Lifting.
This allows us to identify the specific skills that fit
within a given pattern.
eg. A golf swing is a striking pattern
6. Skill Phase
The next step of biomechanical analysis is to break
down the skill into meaningful phases, each of
which may be quite different in terms of
techniques and the underlying biomechanical
principles.
A basic breakdown of the golfer drive includes the
following phases:
8. Detecting Errors
When a performer is making consistent errors in
performances, it can sometimes be difficult to pick
the cause. The effect of the error may be observed
in some other phase or technique of the skill and
mislead the coach into believing the remedy is
somehow linked with the symptom.
In many instances the cause of the error will be found
in large-mass body parts and in the base of support.
10. Balance
Height of the Centre of Weight also
determines the security of the balance
• The lower the centre of weight, the
greater the stability of the body
• The higher the centre of weight, the
less stability of the body
11. Balance
Centre of Weight is found directly in the
centre where all the weight around it is
the same
• The Centre of Weight changes as the
body changes position
• The Size of the Base of Support
determines how stable the body will be in
a given position
• If the Centre of Weight moves outside the
Base of Support then the body will
become more unstable
12. Balance
• “...the most important aspects of the golf swing is
balance and posture” (Jedda Barton, 2008).
• The centre of weight is a key factor with balance. If the
centre of weight is too high than there is less balance and
the chance of losing balance is high. If the centre of
weight is lower than there is greater stability and the
chance of losing balance is lower.
• Golf requires a mix of high and low centre of weight,
depending on the shot. Generally there is a medium
centre of weight, however putting requires a higher
centre of weight.
Centre of Weight
13. Balance
• The base of support is another key factor to consider along with the
centre of weight.
• The base of support shifts when performing a movement and hence
the centre of weight will also shift.
• A narrow base of support will result in less balance and a wider base
of support will result with more balance.
• Golf requires a medium base of support as shown.
• When the position changes on contact of the ball the
base of support will also change as the centre of
weight will cause this to occur.
• If the centre of weight falls outside of the base of
support then the body will be unstable and the
movement will not be as successful.
Base of
support
Force
direction
Pivot point
14. Accuracy
Sideways Accuracy can be achieved if
the arc of the swing is kept in vertical
alignment with the target.
Errors in sideways accuracy
• Unintentional Slice – open clubface
• Unintentional Hook – closed clubface
• Errors caused by swing plane of club
and club face angle
15. Height Accuracy in a golf swing can be
achieved if impact is made at any point
on a straight or direct line to the target.
Errors in height accuracy
• Topping/thin contact
• Fat contact – hitting ground b4 ball
• Errors caused by change in height of
center of gravity
Accuracy
16. Projectile Motion
• The key factors that affect the flight of a golf ball depends on 3 things:
1. The angle at impact- this affects the time the ball stays in the air, the
horizontal distance of the ball and the direction the ball will go (due to
spin).
2. The height at impact- this affects the horizontal distance, the balls flight
time, spin. In addition, the longer the ball is in the air the longer it is
affected by the wind, i.e. If the ball is hit high then the wind will affect the
ball accordingly and the more chance the ball is to hit off target;
depending on the angle at impact.
3. The speed at impact- the faster the ball is hit, the further the ball will
travel given that the angle and height at impact is constant.
17.
18. • Summing Momenta
• Generating Momentum
– Use of Body Segments
– Optimum Stretch
– Sequence of Movement of Body Segments
– Optimum Contribution of Body Segments
– Range of Motion
Biomechanics Of Golf
19. Time
Velocity
trunk
upper arm
forearm
hand
To get the maximum
momentum from a golf
swing a large number of
body parts are required.
“Starting with the major
body parts → smaller
parts until just before
impact.” (B. Abernethy, 2000)
This increase the acceleration and therefore
force on the ball.
20. Summing Momentum
• The speed of the club head will determine the
speed at which the ball will travel at. “... the
key to being able to hit the long ball lies in the
club head velocity” (The Physics of Golf, n.d.).
Therefore the golf club needs to gather a
certain amount of momentum in order to hit
the ball at the desired speed.
• This momentum is gathered by twisting the
body and can be said that this the ‘wind up’
stage of the swing.
• “The twisting swing produces torque on the
club. This torque force changes the angular
velocity of the club, causing rotation” (The
physics of Golf, n.d.).
• “ A typical way people try to hit a ball harder is
to snap their wrists at the bottom of their
swing” (The Physics of Golf, n.d.).
21. • The swing plane of
the golf club follows
a circular path.
Errors in swing plane
cause errors in:
• Height accuracy
• Sideways accuracy
Swing Plane
22. Swing Plane
• “Swing Plane is one of the most technical aspects of the golf swing”
(St.Andrews.com, 2007).
• “Your golf swing should be as natural as possible and yet they say the golf
swing is one of the most unnatural movements in sports” (Golftrainer.com,
2008).
• The swing plane can be pictured as a wheel, the arm (at the top of the
club) is the spoke and your body as the axel. As you spin the wheel spins
one way (backswing) and then the other (downswing).
• Both swings should rotate on the same plane, the club will then hit the ball
square to the intended direction.
• “Poor balance will always alter a golfer's swing plane, causing many errant
shots” (Steve Bishop, 2008).
23. Spin and Swerve
• “Good golfers apply to the golf ball back spin to hold their approach
shots on the green” (Free golf swing tips, 2005).
• Spin is an important part of golf and is useful when it comes to tricky
shots closer to the green.
• A ball will swerve when spin is applied to it and the direction will
determine the type of spin (wind also effects the swerve of the ball).
• There are three types of spin:
1. Backspin
2. Topspin, and
3. Sidespin
• “"A golf ball always has backspin, due to the loft of the club," says
Maxfli's John Calabria. "The ball has a principal axis of rotation
parallel to the clubface and perpendicular to the line of flight. When
this axis is tilted in either direction you get sidespin [which causes
hooks and slices]” (BNET, 2000).
24.
25.
26. Collision Between The Ball And Club
• This is closely related to spin and swerve.
Depending on the angle and direction the
club contacts the ball will determine the
balls angle, direction and spin.
• The momentum of the collision is conserved
because of the high speed of the ball after
the collision and the slowing down of the
club head during the collision.
• The average force between the ball and the
club head is around 3000 lbs.
• The clubface has grooves on it, to produce
friction for the ball to roll up clubface and to
produce a spin on the ball.
• A hook shot is produced
when the club makes first
contact with the side of the
ball furthest away. •A slice shot is produced when
the club makes first contact with
the ball on the inner side.
27. Common
Errors
• No power/distance
• Topping/Fatting the
ball
• Air swing
• Incorrect flight path
of the ball
• Lifting body
• Feet Move
• Summation of Forces
& Generating
Momentum
• Height Accuracy &
Height of CoW
• “same as above”
• Stance & Sideways
Accuracy
• Height of CoW
• Base of Support
Biomechanical
Principles
28. Swinger
• Using Swinger program to analyse golf
swing
1. Identify biomechanical principles in each
phase
2. Identify errors in golf swing by comparing it to
a technically correct swing and applying
biomechanical principles
3. Develop an action plan to correct swing errors
4. Evaluate the process and make further
recommendations for future improvement