Biomechanics Of Golf

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.

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

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.

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

Skill PhaseThe 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:

Preparation

Downswing

Backswing

Follow through

Impact

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.

• Balance • Accuracy • Summing Momenta • Generating Momentum• Swing plane• Common errors• Swinger

Biomechanics Of Golf

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

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

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

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

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

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

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.

• 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

Time

Vel

oci

ty

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.

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.).

• The swing plane of the golf club follows a circular path.

Errors in swing plane cause errors in:

• Height accuracy

• Sideways accuracy

Swing Plane

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).

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. Backspin2. Topspin, and3. 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).

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.

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

Swinger • Using Swinger program to analyse golf

swing1. Identify biomechanical principles in each

phase2. 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 errors4. Evaluate the process and make further

recommendations for future improvement