Biomechanics is the study of forces and their effects on living systems, in particular their effects on humans in exercise and sport. Biomechanics are often used in two particular ways. Firstly, it is used by teachers and coaches to correct the actions during a specific skill of a student or athlete. Secondly biomechanics researchers are continuously using biomechanical principals to assist them in discovering and developing new and improved techniques for performing a skill (McGinnis, 2013). This study will look into the biomechanical principals that are required when executing the Netball shot at goal.
What are the Biomechanical Principals?
Balance and Stability
Shooting action
Ball release
Shooting action
Ball release
Projectile Motion
Shooting Sequence
Shooting Sequence
When preparing for the netball shot,
advanced shooters will place the foot parallel to the shooting side either
slightly in front of their preferred foot or both feet will be shoulder width
apart side by side pointing directly to the goal post. The ideology behind the
positioning of the foot is to provide the athlete with a stable base of support
and to minimize any trunk rotation that may occur during the shooting sequence.
The base of support is the totally area in which the body is supported. An
example of this, when you stand with your legs apart, the area directly
underneath you and between your feet is your base of support. The larger the
base of support, the greater the stability (RUS_QSPE, 2010) . This is why when teaching
children how to play Netball, most coaches will say to land on two feet
approximately shoulder width apart as it provides the learning athlete with a
greater base of support allowing them to be stable when passing the ball. Spreading
your feet side-by-side many people think is what needs to be done in order to
widen you base of support. In fact, in order to widen and increase your base of
support it is suggested to stagger your feet front to back in an anterior-
posterior position (Whiting & Rugg, 2013) . As the athletes get older and have a better
understanding of the game and the skills involved, then will they start moving
all of their weight onto one foot when passing the ball. Maintaining an upright trunk position,
leaning backwards slightly, with their head upright and centered in the middle
of their body will also assist in maintaining a balanced shooting position (Steele, 1993)
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| Figure 1.1 The difference between base of support. As you can see in diagram B, when standing on two feet there is going to be a bigger base of support and therefore, the athlete is going to have better balance and stability. |
A vital factor in many sports is that an
athlete must be able to maintain their balance and stability. When an athlete
loses their stability, it can have an adverse effect on their ability to
perform the skills necessary of the given sport with control. If the athlete
does not have control or a stable base of support then it is likely that
factors such as force production and accuracy will not be as successful as they
would be if the athlete maintained their balance and stability (RUS_QSPE, 2010) .
The base support, balance and stability and
center of gravity are all contributing factors in sport and each rely on one
another in order for one to be successful. Centre of gravity is a point in our
body in which the body is balanced. The height of the center of gravity and
base support can affect the athlete’s stability. When having a shot in netball, the athlete’s center of gravity is generally high, which can result in the
athlete being less stable. This is why it is important for the athlete to
maintain their balance and stability during the preparation and shooting phases
of the netball shot (RUS_QSPE, 2010) .
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| Figure 1.2 A body’s centre of gravity can change, depending on the body’s movement position. A Netball player has many different movement positions in one game; therefore their center of gravity is constantly changing. |
A study by Elliot and Smith (1983) found
that the optimal angle of knee flexion is based on the individual’s preference;
however, the study showed that sufficient force could be produced during the
execution phase of the netball shot if the individual demonstrates adequate
flexing of the knees. The study also showed that more accurate shooters also
flexed their elbow far more than an amateur goal shooter would.
In order to improve the accuracy of the
netball shot, the individual should only extend their shooting hand far enough
to stabilize the ball when preparing to execute the shot. If the shooting arm
is over extended the shooting performance may be unsuccessful. To ensure for
higher accuracy when going to shoot a goal the extension of the knees and
shooting elbow as well as the flexing of the hand and wrist should be done
simultaneously as it will achieve maximum accuracy for the netball shot (Steele, 1993) .
Ball Release
The ball release is an important part of
the netball shot. If the ball release is executed well, then the chances of it
being a successful shot at goal become higher. At the time of the ball release,
the athlete should demonstrate a straight trunk and upright head position. The
same considerations as the preparation stage need to be executed, if the athlete maintains a well - balanced position while the ball is being released, it will improve the accuracy of the shot. For better results, the arm holding the ball should be extended, the
position of the ball should be above the athlete’s head and the ball should be
released at a higher point.
Releasing the ball at a higher point
improves the accuracy of the shot and makes the distance in which the ball has
to travel to reach the goal post a lot shorter. The higher release will also
help avoiding and interceptions that may occur by the defending opponent.
Projectile Motion
Projectile motion simply refers to the
motion of an object that is projected in to the air at an angle. Gravity and
air resistance are the two main factors influencing the projectile motion (Blazevich, 2012) .
Projectile motion affects any object that is thrown into the air, like
the ball when an athlete is having a shot at goal. There are a number of
factors that affect the flight of the ball as well as the distance it will
travel. These are; angle of release, height of release and speed of release.
Each of these factors will vary depending on how tall the athlete is and how
far away they are from the goal post (RUS_QSPE, 2010) .
Shooting
Sequence
The Netball shot can be done in three
different stages; Preparation, execution and completion. During the preparation
stage of the Netball shot the ball should be held in one hand with fingers
spread far enough for the ball to rest on the middle of the fingers. The
non-preferred hand should be lightly resting on the side of the ball for
support. Feet should be shoulder width apart with feet, hips and shoulders
square to the goal post.
When executing the Netball shot, knees need
to be evenly flexed while elbows are slightly flexed with the point of the
elbow pointing towards the goal post. The athlete shooting the goal should push
up with their legs strongly to their toes before extending their arms and
flicking their wrist and fingers upon the release of the ball (Steele, 1993) .
If the preparation and execution phase are
done correctly, the shooting arm should be completely extended above the head,
which will assist in the follow through and a stable base will be maintained (Government of Western Australia Curriculum Council , 2011).
The Netball Shot mimics the push-like
movement pattern. The push-like movement pattern is the movement that will
occur when pushing something. The push-like movement pattern is such a common
movement pattern and provides athletes with many benefits. A particular benefit
that relates to the Netball shot is the straight-line movement that occurs at
the end of the chain when all joint rotations move simultaneously. Through
moving in a straight- line, a highly accurate movement can be executed just
like the Netball Shot (Blazevich, 2012) .
To execute a successful shot, it is
important for the athlete to obtain maximum force, as it is essential to
combine all the forces that have been applied by different body parts. This is
known as the summation of force. The summation of force is influenced by four
main factors; the number of body parts used in the movement, order and timing
of their involvement, force and velocity generated and a way in which the body
and body parts are stabilized and balanced. Again, each of these is seen when
executing the Netball shot (RUS_QSPE, 2010) .
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| Figure 1.3 The sequential summation of force from body parts is essential to maximize the force production. This is the same sequence that an athlete would use when going to shoot a goal. |
How else can this information be used?
This shooting technique is not only used in
Netball, but in many different ball sports. A basketball player is going to
encounter many of the same Biomechanical principals that a netball player will
throughout the game, however each of these in most circumstances will be
applied slightly differently. For example the free throw in basketball also requires
the same biomechanical principals during the preparation phase such as the base
support, balance and stability and center of gravity. As Basketball is a more
physical game and tends to be much quicker as players are able to move with the
ball. The athlete’s base of support is often changing in order to cater for
their constant change in direction. Both the Netball and Basketball shooting
actions contain the same biomechanical principals. The ball release,
projectile motion and how much force that should be applied, all need to be
taken into consideration when executing the shot.
Through analyzing the Netball shot we can
now use our understanding of the biomechanical principals in applying
them to different sports. After investigating the biomechanical principals needed to successfully execute the Netball shot, the quality and consistency of the
netball shot can be greatly increased. If the teaching of these biomechanical
principals is done at a beginner and amateur level then it is likely that when
players reach an elite level their understanding to the approach and
consistency in their shooting is going to be far greater. The information
presented should provide coaches and teachers with the appropriate theoretical
background needed to teach the Netball shot to junior players and improve on
the existing techniques of more experienced players.
References
Blazevich, A. J. (2012). Chapter 17 The Kinetic Chain. In Sports
Biomechanics The Basics Optimising Human Performance (pp. 196-197). London
.
Government of Western Australia Curriculum Council . (2011).
Netball . Physical Education Studies - Support materials for practical
examinations , p. 11.
McGinnis, P. (2013). Biomechanics of sport and exercise.
Human Kinetics.
RUS_QSPE. (2010). Applying Biomechanics to Sport.
Retrieved from Secondary Health and Physical Education :
https://www.oup.com.au/titles/secondary/health__and__physical_education/physical_education/queensland/9780195573862/03_RUS_QSPE_3pp.pdf
Steele, J. R. (1993). Biomechanical Factor affecting
Performance in Netball.
Whiting,
W. C., & Rugg, S. (2013). Five factors determine stability and mobility.
Retrieved from Human Kinetics :
http://www.humankinetics.com/excerpts/excerpts/five-factors-determine-stability-and-mobility
