Tuesday, June 19, 2018

What are the Biomechanical Principles behind achieving optimal accuracy in a netball pass?

Kate Hodgkison, Louise Back & Jocelyn Teggerth 

Netball is a sport that is played by over twenty million people over a range of eighty countries across the world. It is usually played by women, and is one of the most common women’s sports in Australia. Although netball is traditionally identified as being a sport that is played by women, many men are also involved in the game (Mccaw, 2018). Netball is a game that involves the fast acceleration of breaking free from an opponent, explosive and sudden movements and quick direction changes, with the inclusion of elevating jumps and leaps, which are made when players receive passes, intercepts or even a rebound when there is an attempt of goal (Steele, 1990).


When looking at the question’ what are the biomechanical principles behind achieving optimal accuracy in a netball pass?’, biomechanics has been found to be a sport science field that looks at the laws and factors of mechanics and physics around improving human performance. It allows us to gain a better understanding of the performance in physical activity. Understanding the biomechanical principles can help with the optimisation of sports performance by being able to develop the most efficient and effective techniques on specific skills which can be done through stimulation, measurement and modelling (Knudson, 2007).


Throughout the game of netball there are three main passes and this includes bounce pass, chest pass and shoulder pass. From analysing and looking at the biomechanical principles behind each of these individual passes this can help identify what pass is the most effective in different game like situations. Being able to examine the biomechanics that occur whilst performing a pass will allow players to perform and understand the pass better, and how it should be used and executed. By looking at the factors that create effective power, accuracy, distance and speed in the different passes, this can identify what movement patterns need to be established to be able to execute and perform these passes to achieve the optimal performance and accuracy that is needed to be undertaken by players in their passing technique (Shakespear & Caldow, 2009).


To be able to propel and accelerate a netball from one player to another down the netball court requires skills around speed, accuracy and distance. The effectiveness of players to be able to successfully pass the ball is vital in the outcome of the team as a whole. Developing the knowledge of the basic terms can do this and physics behind the skill of the pass, once this knowledge is obtained will help to increase the accuracy of the chosen pass. When the player selects an appropriate pass for the game like satiation, the considerations that need to take place are the power, the velocity/ speed, distance and accuracy that can be attained (Blazevich, 2010).


Throughout this blog the specific Biomechanical Principles behind achieving optimal accuracy in a netball pass are explored through analysing information, videos and photos around the specific techniques needed within these three different types of passes that are used in netball. Some key principles will be covered below are listed:
  • Velocity
  • Projectile motion
  • Newton’s laws
  • Balance
  • Kinetic chain
  • Acceleration
  • Force
  • Centre of mass
  • Impulse momentum relationship
  • Projectile angle
  • Momentum




This chosen video shares a range of strategies to use around performing a correct bounce, chest and shoulder pass, which are the three main passes in netball. This visual also discusses how and when these passes are used in a netball game situation and how to effectively perform the skill to maximise accuracy.


Chest Pass

The chest pass is the most common type of pass used in netball (Human Kinetics, 2018) and is best used across short distances. It is performed best when the player steps forward, pushes the shoulders and elbows forward, and stretches their fingers and hand tendons and finally finishing the pass with a rapid hand and finger extension (Blazevich, 2016). There are four phases in a chest pass.

Phase 1 - StanceTeaching Cues:

  • “Fingers spread behind the ball in a W shape”
  • “Elbows low and close to body”
  • Head up, eyes fixed on target”


Centre of Mass

Ensuring balance and stability is critical in a successful netball pass, as without it, it is much more difficult to aim accurately. In order to gain this balance and stability, a players centre of mass (COM) must be established. COM can be described as “the point at which the mass of the body is evenly distributed in all directions” (Blazevich, 2016). In order to achieve this COM, the players knees should be slightly bent, feet shoulder width apart and weight should be evenly distributed (Netball Skills - Chest Pass, 2010).



Figure 1. As pictured above, the player has their feet shoulder width apart, weight is evenly distributed through both feet and her torso/head are directly in line with her feet. This makes the COM roughly in the middle of the body and supports balance and stability.

Newton’s Laws

Balance and stability is also affected by Newton’s First Law which is “an object will remain at rest or continue to move with constant velocity as long as the net force equals zero” (Blazevich, 2016). So when forces that act upon the body equals zero, no movement will occur and balance will be achieved. When this balance is achieved it allows time for decision making and skill execution, which is critical in netball.

Grip of the Ball

Grip of the ball is a crucial aspect to executing the chest pass. A players hands should create a W shape behind the netball (thumbs together and fingers spread holding the ball) and the ball should start close to the players chest (Chest Pass like a Pro, n.d.). Ensuring hands are in this position is critical as it allows for maximum finger/hand/wrist extension which is highly important for later phases in the chest pass.




Figure 2. Hands are in a W shape and fingers are spread around ensuring a secure grip on the ball. This hand positioning will allow for a powerful chest pass.


Phase 2 - PreparationTeaching Cues:
  • “Step forward with one foot and transfer the weight”
  • “Keep eyes on target”
Impulse-Momentum Relationship
To have greater power behind a pass we need a larger momentum. Momentum is the product of mass and velocity (P=m x v) (Blazevich, 2016). If we wish to change an object's momentum (i.e. a netball) we must apply a force. The larger the force applied, the greater the change in momentum will be (Blazevich, 2016). This can be done in netball through stepping forward when throwing the ball. To drastically increase momentum, the force must be applied over a longer period of time. This is referred to as impulse (J). Therefore, “the greater the impulse, the greater will be the change in momentum” (Blazevich, 2016), this is the impulse-momentum relationship. By stepping back and through with the chest pass, there is an increased fore and therefore impulse-momentum relationship and a more powerful pass.



CHEST PASS VIDEO. https://www.youtube.com/watch?v=59lGIg8Y8Eg

Figure 3. It can be seen above that by stepping forward when the ball is thrown, there is more momentum behind the ball, resulting in a more powerful throw.


Phase 3 - AccelerationTeaching Cues:
  • “Push ball away from chest”
  • “Extend arms and wrists”
  • “Use fingers to control direction”
Kinetic Chain
For a successful chest pass to occur, joints in the bodies kinetic chain are required to move in a single push like movement. The name of the push like movement explains itself. It is a movement as if we are pushing something (Blazevich, 2016). A critical benefit to the push like movement pattern is the result of a high overall force. This is due to the cumulative forces created at the torques because of all the joints working simultaneously (Blazevich, 2016). Another benefit to this movement pattern is the result in a straight line movement due to the simultaneous joint rotations (Blazevich, 2016). The chest pass is an example of an open kinetic chain action (one end of the chain is free to move). The kinetic chain is a critical component of the acceleration phase of a chest pass because it allows for a high level of accuracy as well as a large production of force (Blazevich, 2016).




Figure 4. This image shows the kinetic chain, as it can be seen the arms start bent, then extend through the shoulders, then the elbows followed by the wrists/fingers. This push like movement allows for a high overall force behind the ball due to the accumulation of forces at each torque.


Newton’s Laws

Newton’s Second Law of Motion can also be applied during the acceleration phase of the ball. This law states that “the acceleration of an object is proportional to the net force acting on it and inversely proportional to the mass of the object” (Blazevich, 2016) or F = mxa. In other words, the acceleration of the ball is determined by its weight and also on the force that is applied. For example, the lighter the object, the faster is will accelerate. In a netball pass, this law is evident when the ball gets released from the players hands, it accelerates towards the desired target (another player). Knowing how much force to apply can improve the accuracy/distance of the throw.



Impulse-Momentum Relationship


As previously discussed, the impulse-momentum relationship is referred to as the greater the impulse applied to an object, the greater the change in momentum will be. This can relate to the acceleration phase of the chest pass, as force can be applied over a slightly longer period of time, which can allow for a greater velocity.


Phase 4 - Release Phase

Projectile motion refers to the movement of an object that is projected as a specific angle into the air. The projects object can move between horizontal (0 degrees) and vertical (90 degrees), with gravity affecting objects that have a vertical movement (Blazevich, 2016). Projectile motion is influenced by projection speed, projection angle and relative height of projection. These factors all effect how high and far the ball will travel. As the player will always have a target to throw to, the projection speed and relative height of projection is important. If a target player is further away a faster projection speed is needed, in order for the object to travel the required distance (Blazevich, 2016). The relative height of projection refers to the “vertical distance between the projection point of an object and the point at which it lands” (Blazevich, 2016). When passing a netball we want the ball to land at the players chest/slightly above for an easy catch making the relative height is negative (Blazevich, 2016). Knowing these factors can allow for an accurate pass with little to no mistakes.

Shoulder Pass

A shoulder pass is a one handed throw that is used to gain distance with speed and accuracy in a netball game. It is vital to make sure the shoulder pass is not loopy as this allows the opposition to have the chance of picking the pass off resulting in a turn over. The ball should be thrown at a greater angle of release so that it can outwit defenders. A good shoulder pass is produced by using your wrists, fingers, elbows, arms and be able to use the entire body weight to generate the speed needed to make the distance and propel the pass forward to a player. To perform the shoulder pass, the joints are extended in the kinetic chain and are used sequentially, which is one after the other (Blazevich, 2010). As the shoulder pass is a throw like movement pattern the summation of forces and momentum is used to generate a “wind up phase” movement, this is then transferred through to the release stage, allowing a high amount of acceleration, speed and force to occur. As a result of applying the different biomechanical factors it allows the ball to travel at a high velocity and travel further down the court.

Figure 5: Sequence of phases in a netball shoulder pass showing the process of performing an effective and accurate pass (Eliardiani, 2012).
Preparation Phase
Through the preparation phase of a shoulder pass the body needs to be positioned to support the centre of mass, this can occur by the player having their legs shoulder width apart. In this phase the body is stationary with the ball being held in both hands at the front of the body being ready to make the decision and pass. In this phase the player needs to be able to find their centre of mass, this will help achieve optimal accuracy when about to throw the netball. This is finding the point in the body where the weight can be distributed equally. As found balance is quite vital in this phase as it prepares the body to be able to successfully perform the required skill. Newton's First Law can come into effect when trying to achieve a balanced centre of mass as “ 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). Being balanced in a netball game allows players to get in position to make a strong shoulder pass and allow time to be able to make quick decisions and execute the technique.
Wind up phase

The wind up phase of the shoulder pass focuses on having the weight of the body on the back foot at the start of the throw, the ball needs to be held with two hands before it is then guided by one hand when the arm is placed back behind the shoulder, the player must move the ball in a posterior direction which is to the back of the body, a slight rotation in the hips is needed on the preferred side with a drop of the shoulder slightly backwards. Elbows need to bent in the wind up phase, as you are about to exert the force into a forward motion. The movements that are included in this wind up phase are linked within the biomechanical principles of impulse. Impulse is a measurement of the force that is applied for a time that is specific. Impulse= force x time and has the units Ns which refers to Newtons seconds. Impulse relates to sports such as netball, which has a throwing technique, which requires the players to apply a large amount of force for as long as possible. This occurs in the wind up phase as we are preparing the body to be able to apply that force, as we want to increase the speed of the arm (TeachPe, 2012). The greater the acceleration of the arm in the wind up phase, the larger the force that is being applied to the netball. This will increase momentum of the shoulder pass and increase the speed of the netball, which will them improve the accuracy (McGinnis, 2005).  

Propulsion Phase

During the propulsion phase students should be stepping forward with the opposite leg to their throwing side, making sure they are transferring weight forward as the throwing arm comes through at a fast speed. It is important to accelerate from the elbow, as this is vital in bringing the arm in front of the body so the ball can move in a forward movement. The biomechanical principle that is looked at in the propulsion phase is the kinetic chain. When participating in the propulsion phase a throw like movement pattern is made. The joints of the kinetic chain are extended sequentially, referring to one after the other. By propelling and extending the arm at a fast rate to pass the ball this results in a highball release velocity. The joints increase the velocity release as the momentum comes from the production of large muscle forces. These muscle forces are used in the propulsion phase to accelerate the ball at a high velocity so it reaches the other player with accuracy and speed (Blazevich, 2010).
Release Phase

During the release phase of the shoulder pass, the player should first have a twisting action in the hips to help accelerate the pass by bringing the hips forward in the same direction as the throw. The player needs to make sure there should has a twisting action bringing it forward to the direction of where the height of release is established and the angle of the motion. Players need to also allow a running through action to occur after words to keep momentum, this will be effective as the larger the momentum, the larger the force. The biomechanical principle that is evident through the release phase is the projection angle. The angle of projection is important when looking at the trying to reach the greatest distance horizontally as the pass needs to be projected at an appropriate angle. As the aim of the shoulder pass is to cover distance, this is determined by the projection speed and the projection angle (Blazevich, 2010). When looking at individual abilities and factors to produce speed, such as the difference in muscle mass and performance techniques these will determine how far the netball will go and the speed that it will travel, this will vary between each person. When looking at the height and the distance of the shoulder pass in netball the projection angle is important. To be able to reach a maximal distance, when throwing the netball, the angle that will optimise this would be 45 degrees. This results in maximum distance because of the equal magnitude of horizontal and vertical velocity. If the projection velocity/speed travels at a faster rate and an optimal angle the further the object will travel, which is shown in figure 3. To calculate the projection angle / motion use the equation v= u+at which is final velocity (v) = initial velocity (u) plus acceleration multiplies by time (at) (Blazevich, 2010).
Figure 6: When analysing figure 6, this shows that the maximum range of projectile relies on the angle of projection. For the netball to make the distance of the court from player to player the angle of release should be at 45 degrees, as this obtains a good amount of height and covers a further amount of distance compared to the other angles of release.


Bounce Pass

Within netball, the bounce pass is often the passing shot that is less commonly used during a game situation. It requires players to apply extension of their arms and elbows, in combination with accurate flexion of their arms in a downward trajectory. The use of a bounce pass is most effective when reaching around another player’s body within short distances or confined spaces. The techniques that are involved in the bounce pass are highly relative to Newtons Third Law of Motion. This law states that “for every action there is an equal and opposite reaction” (Hewitt, 2017). The analysis of the bounce pass in netball will be evaluated with the implementation of the biomechanical principles; action force, acceleration and work. These biomechanical principles will be discussed in relation with the preparation stage, the power production stage, the release stage, and the follow through stage.

1. Preparation
Through the preparation stage of a netball bounce pass, the player should hold the ball accurately at chest level with both hands distributed evenly across the ball. The knees should be bent to a certain degree, with their feet placed one in front of the other. To successfully and accurately complete the bounce pass the player must exert these crucial steps for preparation:

  • Step with leading foot (or non-pivot foot)
  • Hold ball with dominant hand and guide downwards with non-dominant hand to stimulate correct direction
  • Ensure arms are extended and flexion is applied
  • Correct rotation of the hips on dominant hand side of the body
  • Opposite foot to their throwing arm is placed in front of the other
Every movement that is associated within these steps is caused by the exertion of an action force. The action force refers to the energy expressed in a linear physical action or movement (Blazevich, 2017). In this situation, whilst the ball is travelling in a downward trajectory an action force is applied. After the ball has left the hands of the player it enters the release stage and the force of the ball transfers in an upward direction, leaving the hands at a rapid phase.
2. Power Production

Through the power production stage of the bounce pass, the arms are extended with flexion applied to throw the ball towards the ground in a downward trajectory. As mentioned previously, the action force applied on the ball will determine the direction and speed at which the ball will travel in. When demonstrating correct technique through the power production stage of a bounce pass, the player must:-       Stand with knees bent and stance of legs is to be one in front of other-       Exert force through elbows to create a pushing motion towards the ground-       Rotate hips according to the intended direction of passThe movements that are included in these steps of power production fall within the biomechanical principle of acceleration. The term acceleration refers to the relative change in velocity (Blazevich, 2017). The acceleration occurs when the player exerts a downward force propelling the ball down towards the ground through the flexion of their arms with their knees bent. The player is applying acceleration by generating power through their knee drive, hip rotation, and by applying force to the ball through using the correct arm movements to project the ball to the ground.

3. Release


During the release stage of the bounce pass, the player should first begin by stepping forward using the correct stance with one foot to the side of, or in front of the other. The next step is bending their knees to optimise maximum force and acceleration when releasing the ball. Next is to ensure hips rotate around in the opposite direction of the pass. Finally, players must ensure their arms are flexed with maximum extension to release the ball. As mentioned previously, force and acceleration are two biomechanical principles that are evident within the preparation and power production stage of the bounce pass. Throughout the release stage, the biomechanical principle of ‘work’ can be evident. The term ‘work’ refers to the amount of energy that is used to cause a given movement (Blazevich, 2017). When the player Is releasing the ball, work is evident through the force applied on the ball caused by the players bent knees and extension/flexion of arms, to the distance that the ball has travelled once released.


4. Follow Through

Figure 7: Student Image of bounce pass footwork demonstration

The follow through stage of the bounce pass is the fourth and final stage of performing the pass. During the follow through stage, the player will feel a small upward pull on their fingers once the ball has left their hands. Once the player has exerted maximum force, acceleration and work when releasing the ball, the follow through will see the opposite foot to the throwing hand curve around the body (refer to figure 1). The back knee is bent further to the ground than the front knee in order to generate power and to create more distance on the release.


How else can this information be used?


Many of the biomechanical principles relative to chest pass, shoulder pass, and bounce pass in netball also hold the same characteristics as the same passes performed in Basketball. Rotating the hips and applying full extension and flexion of the arms when throwing a netball, can be seen similar to the preparation phase of executing a chest pass in basketball. For example, in order for a basketball player to optimise full force of their chest pass, they must flex their hips and lean forward to demonstrate the mediolateral axis of rotation (Edwards, 2017). The projectile motion of the basketball can be executed by bending the knees with feet staggered at shoulder width apart and releasing the ball into the air in an upwards direction by applying force to the ball through the extension of the elbows. Obviously, there are some minor differences in performance between the netball and basketball optimal passing techniques. However, they do share biomechanical similarities through accurate execution. Coaches can use the information provided to understand the techniques involved with perfecting the accuracy and dispositions of these netball passes. In order to further understand and enhance a player’s accuracy of a particular netball pass, coaches or academics can further their research by using iPhone/android apps such as coaches eye, available for download in the app store. This app allows for participants to record and playback videos of passing shots performed by the player and analyse the overall accuracy in order to find areas that may need modifications or improvements. Apps like coaches’ eye are beneficial as they allow for players to develop a deeper understanding of how to improve their optimal performance in achieving accuracy in these netball passes.



Reference List




  • Blazevich, A. (2017). Sports biomechanics: the basics: optimising human performance. Bloomsbury Publishing.
  • Hewitt, P. (2017). Newton’s Third Law of Motion. Building an understanding of physical principles. 84(2), pp. 12-14
  • Intosport. (2010). Netball Skills - Chest Pass [Video]. Retrieved from https://www.youtube.com/watch?v=5dhjrWMdQww&t=135s Blazevich, A. (2017). Sports biomechanics: the basics: optimising human performance. Bloomsbury Publishing.
  • McGinnis, P.M. (2005). Biomechanics of Sport and Exercise (2nd Ed.). Illinois: human Kinetics.

  • TeachPE.  (2012). Retrieved from http://www.teachpe.com/biomechanics/forces/impulse
















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