Skill Acquisition and Biomechanics for Physical Educators Blog
MAJOR QUESTION: What biomechanics are involved to ensure optimal technique of maximal accuracy and distance with a driver off the tee in golf?
The primary goal of using a
driver in golf is to hit the ball as far and as accurate as possible and to
land the ball on the fairway, this sets up the next iron shot (Hume, Keogh
& Reid, 2005). A successful drive in golf can set the hole up for a
par, or below for a golfer. A driver is predominately used for hitting the
ball long distances as it can utilise a greater range of motion and
larger forces then any of the other clubs in a golf bag. The mechanics of a golf stroke include
five phases; these are as follows; the set-up, the backswing, the downswing,
the impact and the follow through (Keogh & Reid, 2005). The optimal
technique throughout these phases of the ideal golf swing can help to
improve overall performance of distance and accuracy and also reduce the
risk of serious injuries related to golf (Keogh & Reid, 2005).
Momentum is defined as the product of mass (matter of object) and
velocity (speed in a given direction), or measure of motion composed by a
body (Blazevich, 2007; McGinnis, 2013). The larger the mass of an object
and the more momentum it has, the larger the force will be created when
the club head hits the ball on impact (Blazevich, 2007). Momentum plays a
huge role in the swing phases of the tee off in golf. This transfer
of momentum is evident through a professional golfer when the correct
technique is performed by them at tee off. The tee off with a driver in golf
can be broken down into four major swing phases, plus a set up of shot and
preparation of stance phase. These four stages are; the backswing, the
downswing, the impact and the follow through (see figure 1).
Figure 1: This illustration shows
the four swing phases of the tee off with a driver in
golf. A smooth transition between phases enables a successful shot
that has distance whilst maintaining accuracy to be played.
SET UP- PREPERATION
The posture and alignment must be addressed correctly
to set up before the swing of the golf club occurs. Firstly the stance must be
focused on, the golfer must take into consideration balance and posture (Maddalozzo, 1987). If a golfer has
their feet positioned to close together they may find it difficult to turn
freely and to their fullest extent (Maddalozzo,
1987). If a golfer positions their feet too far apart they may find it
to hard to generate enough maximum force, through prohibiting the necessary leg
drive that is needed to power the ball (Maddalozzo, 1987). Therefore, the golfer must spread their feet
approximately shoulder width apart (refer to figure 2) (Maddalozzo, 1987). The golfers’ centre of
mass should be evenly spread over both feet during this stance as well (Kawashima, 1994). This can allow
for production of energy to be maximised when transferred through the body, to
the club and onto the ball (Kawashima,
1994; Maddalozzo, 1987). The golfers left arm must be straight while the
elbow must be slightly bent on the right arm (refer to figure 2) (Maddalozzo, 1987). A straight left arm ensures
the golfer is able to increase the speed and range of motion of the club head (Maddalozzo, 1987). The bending
left arm assists in decreasing the risk of delivering the club head outside of
the target (e.g. the teed golf ball) (Maddalozzo, 1987). The golfers head must also be directly over the
top of the ball to ensure that the eyes are focused on the target (the ball)
(refer to figure 2) (Maddalozzo,
1987).
Figure 2: This diagram shows the preparation in
order to execute a tee off shot with a driver in golf. The three things
highlighted (by numbers) are the stance, head position and arm positioning;
these things are important for balance and posture before commencing the skill.
The main purpose of the
backswing is to position the club head so that the golfer can execute an
accurate and powerful downswing (Hume, Keogh & Reid, 2005). By doing this
it stretches the golfers’ muscles and joints in charge of generating the power
behind the shot (Hume, Keogh & Reid, 2005). The first movement of the
backswing involves a backwards and upwards motion of the club head, the torso
also rotating to the direction of the club, which in this case is to the right (Chu Chu ,
Sell & Lephart, 2010). The left knee is also rotating as are
the hips and this is done in one single motion (refer to figure 3) (Chu Chu Chu
Figure 3: This image shows the
backswing of a golfer at a tee shot at its highest point just before commencing
the downswing. Here it is visible to see the rotation of the torso, and knees whilst
the hands are above the eye line.
The purpose of the downswing is to return the club
head to the ball on the right plane with maximum velocity provided from the
backswing and downswing (Chu Chu ,
Sell & Lephart, 2010). This acceleration from the top of the
backswing to the impact of the ball generally takes between 0.02-0.10 seconds (Myers et al., 2008). With the
initiation of the downswing the body weight shifts from the trailing foot at
the top of the swing towards the leading foot (refer to figure 4) (Hume, Keogh
& Reid, 2005). The angle of the wrists should return back to a normal
un-hinged state just before the impact on the ball and it is said that this
contributes significantly to club-head velocity (refer to figure 4) (Chu, Sell & Lephart, 2010;Hume,
Keogh & Reid, 2005). The power produced by the legs in the downswing plays
a major role in the drive for a golfer. This kinetic energy then moves up
through the arms and provides the necessary power for the acceleration of the
club head (Blazevich, 2010; Chu
Figure 4: This image shows the downswing of the
golfer at a driving tee shot, from its highest point down to just prior to
making contact with the ball. It is clear to see the transfer of weight between
the top of the downswing to the bottom of it.
THE IMPACT
The aim of the impact is to strike the ball flush
with the club-head at maximum velocity produced during the backswing and
downswing (Hume, Keogh & Reid, 2005). At impact the right-handed golfer
should have the majority of their body weight onto their lead-foot (refer to
figure 5) (left) (Maddalozzo, 1987).
The wrists also need to be straightened to enable them and other body parts to
produce maximum force upon the ball (Maddalozzo, 1987). It is also important that the hands are
positioned in line with the club head or slightly ahead of it on impact (refer
to figure 5) (Hume, Keogh & Reid, 2005). By moving the weight of
the body forward, this is creating momentum which can be transferred from the
body, down the shaft of the driver and onto the club-head, this then travels onto
the ball once impacted (refer to figure 5).
Figure 5: This illustration compares the set-up and
preparation phase with the impact phase, the majority of weight is placed on
the lead foot on the right-hand side (impact phase).
THE FOLLOW-THROUGH
The main purpose of the follow-through is to
decelerate the momentum built up from the body and the club head during the
backswing, downswing and impact; this is done by using eccentric muscle flexion
(Hume, Keogh & Reid, 2005). During this phase both shoulders rotate
forwards towards the direction the ball has been struck (refer to figure
6) (Hume, Keogh & Reid, 2005). When the hands reach shoulder level
both the elbows flex to decelerate the speed at which the arms are moving and
the torso rotation (Hume, Keogh & Reid, 2005). As the torso and hips rotate
the majority of the body weight is now planted on the left leg and it rotates
outwards to absorb this load (refer to figure 6) (Hume, Keogh & Reid,
2005). To finish off the follow through, the golfer must be in a balanced
position with the torso and head facing the direction the ball is travelling in;
the hands should also finish behind the left ear (refer to figure 6) (Hume,
Keogh & Reid, 2005).
Figure 6: This diagram shows the follow-through of
the golfer at a driving tee shot, from just after impact until the completion
of the follow-through.
MAINTAINING ACCURACY ON A GOLF BALL
Maintaining
accuracy as a golfer at a driving tee shot is very important, if achieved and
the ball lands on the fairway this sets ups the next iron shot with increasing the
chance at making the green in regulation. Once a ball has been struck, it may
start off in a straight trajectory but then veer off to the left or right (Libkuman, Otani & Steger,
2002). In golf, veering off to the right is generally known as a slice,
veering to the left is generally known as a hook. This is done so when
accidental spin is put onto the ball due to a slight pull or draw of the driver
face (Libkuman, Otani
& Steger, 2002). This spin affects the golf ball moving through the atmosphere,
as one side of the ball is grabbing the air, this causes higher friction
between the ball and the air (refer to figure 7)(Blazevich, 2010). These particles in
the air then start to spin the ball causing one side of the ball to slow down
whilst the other side still moves freely (refer to figure 7) (Blazevich, 2010). This slow
moving air on the one side of the ball forces it to swing away from its
intended straight trajectory and is known as the Magnus effect (refer to figure
7) (Blazevich, 2010). A
professional golfer who has had coaching and understands that they may have a
natural hook or slice can then alter their club head grip and/or technique to
combat this (Ming &
Kajitani, 2003; Chu , Sell & Lephart,
2010). A higher grip on the golf club generally means a longer lever is
created and can generate greater velocity, but control may be lost (Chu Chu
Figure 7: This image shows the Magnus effect when
the ball is in flight after it has been struck. It is clear to see
the friction the ball has on one side which causes this unwanted spin to
occur.
MAXIMISING DISTANCE ON A GOLF BALL
The golf swing consists of several biomechanical
principles, one of these is the ability to maximise the force, this transfers
into distance. The three Newton
‘An object will
remain at rest or continue to move with constant velocity as long as the net
force equals zero’ (Blazevich, 2010, p. 44). Inertia is present in every object
containing mass; therefore it will remain in its current state unless an
external force is applied to it (Blazevich, 2010). Force can be defined as ‘the
effect one body has upon another’ (Nesbit&
Serrano, 2005). In terms of a golfer hitting a ball off the tee with a
driver, this happens when the club strikes the ball causing an impact. The
force transferred from the club head onto the golf ball’s inertia disrupts it
from its current state. So in theory the more force striking the golf ball the
longer distance it should travel (Chu
‘The acceleration of an object is proportional to the net force acting on it and inversely proportional to the mass of the object’ (Blazevich, 2010, p. 45). To change an objects state of motion, an external force must be applied to it. This means that the less mass an object has, with force, the faster it will accelerate (Blazevich, 2010) Acceleration can be defined as ‘the rate of change of velocity’ (Blazevich, 2010, p. 7). Applied to a golfer who is teeing of with a driver, this increased momentum of the club head by the muscles and joints produces greater acceleration of the club head before the impact on the ball (
‘For every action, there is an equal and opposite reaction’ (Blazevich, 2010, p. 45). This recognises that if a force is placed on an object, an equal and opposite force known as a reaction will be placed on that object that has created that initial force (Blazevich, 2010). This affects a golfer who is teeing off with a driver when they strike the ball; on impact this energy projects the ball forward. There is also a reaction from the ball on the club-head and up the shaft, completing a proper follow through allows energy to be transferred into this reduction of momentum by flexion of the joints and muscles within the body (Hume, Keogh & Reid, 2005).
ANSWER:
When analysing the tee-off with a driver it is important to break the
skill down into certain phases to achieve maximum distance whilst maintaining
accuracy of the shot. The four swing phases include; a backswing, downswing,
impact and follow through with set up and preparation phase also being important
for the shot. All of these swing phases are just as important as the other and
should be completed sequentially. If one or more of these phases are not completed
smoothly with the optimal technique it may lead to poor contact with the ball;
this may mean it does not travel in the desired direction. The
angle of the club-head is vital to; if it is slightly off the Magnus effect
will take hold of the ball so it will veer off of its intended course. Some
debate still remains on what the optimal biomechanical techniques are to assist
golfers when they tee of for maximum distance whilst maintaining accuracy.
However, it is suggest that golfers’ practice their own techniques as to what
may work best and what is successful for them, by following the biomechanical
principles stated.
HOW ELSE
CAN WE USE THIS INFORMATION?
The biomechanical principles of the drive in golf
can be applied to many other sports. In baseball and cricket a similar
technique can be seen as the momentum of the muscles and joints transfers into
force when the bat strikes the ball (object). This information gained from
biomechanics can assist in fine-tuning techniques, especially for professional
athletes who strive for any edge over their competition. It is also important
that these optimal techniques are established by professionals’ healthcare
workers to assist both amateur and professional sportspeople in preventing injury.
This knowledge also assists professional educators such as teacher or coaches,
who may want to improve technique or to be supported in explaining where individuals
may be struggling within the skill.
REFERENCES:
Hume, P., Keogh, J., & Reid, D. (2005). The
Role of Biomechanics in Maximising Distance and Accuracy of Golf Shots. Sports
Medicine, 35(5), 429-449.
Kawashima,
K. (1994). Comparative analysis of the body motion in golf swing. Journal Of
Biomechanics, 27(6), 672.
Keogh, J., & Reid, D. (2005). The role of
biomechanics in maximising distance and accuracy of golf shots. Sports
Medicine, 35(5), 429-449.
Libkuman, T., Otani, H., & Steger, N. (2002). Training in Timing
Improves Accuracy in Golf. The Journal Of General Psychology, 129(1),
77-96.
Maddalozzo, G. (1987). SPORTS PERFORMANCE SERIES:
An anatomical and biomechanical analysis of the full golf swing. National
Strength & Conditioning Association Journal, 9(4), 6.
McGinnis, P. (2013). Biomechanics of sport and
exercise. Champaign , IL
Ming, A., & Kajitani, M. (2003). A new golf swing robot to simulate
human skill––accuracy improvement of swing motion by learning control. Mechatronics,
13(8-9), 809-823.
Myers, J., Lephart, S., Tsai, Y., Sell, T.,
Smoliga, J., & Jolly, J. (2008). The role of upper torso and pelvis
rotation in driving performance during the golf swing. Journal Of Sports
Sciences, 26(2), 181-188.
Nesbit,
S. M., & Serrano, M. (2005). Work and power analysis of the golf swing. Journal
of sports science & medicine, 4(4), 520.
