Thursday 19 June 2014

What techniques and biomechanics principals might a netballer employ to increase the speed of a 'chest pass'?

What techniques and biomechanical principals might a netballer employ to increase the speed of a ‘chest pass’?

Introduction:

Netball, for many years now is one of the most popular team sports in the world played by an estimate of 20 million people over the countries (International federation of netball association, 2009). It has been stated that netball in Australia is the second most popular organised recreational activities, therefore is a popular sport to be taught by practitioners. The chest pass is the first pass, which will be taught to use in netball, as it is the pass which is relied on and used the most as it is the most accurate and controlled pass, especially for short distances. Biomechanics has been defined as a study of movement with special emphasis on human beings through the use of science of mechanics (Hatze, H.1975). Through the use of biomechanics we are able to analyses and give reason for the skills output and what we may expect or see as the end result of that specific skill. For example the netball chest pass has a significant amount of intricate movements and factors, which determine the speed, and accuracy of the ball. The chest pass in netball is one of the passes, which is highly used, as it is seen to be the most efficient pass. Therefore it is my understanding that there is a lot of biomechanics behind a chest pass in order to produce the correct amount of speed needed to make the intended distance and accuracy. Speed and accuracy of a chest pass is significantly important, as they do not want their opponent to intersect the pass. This blog will provide a guide of the important biomechanical factors a chest pass involves.

The following video is a detailed analysis of the key elements and biomechanics of a chest pass and how to perform a chest pass, both basics and in a game situation. The main techniques of a chest pass start with the positioning of the hands, then the feet leading into the transformation of the weight from the back to the front and the extension of the arms and wrists. The biomechanics principals behind a chest pass are the kinetic chain movements required for the transformation of weight from the proximal and distal end of the movement. The power and energy needed to perform the chest pass is adequate as to generate a maximal force behind the speed and to transfer weight from the back to the use of their abdominal and arms requires energy.






Kinetic Chain:

For a successful implement of a chest pass in netball all of the joints in the kinetic chain are required to simultaneously move in a push-like movement patter (Blazevich. A. 2010. P.196). A push-like movement pattern explains its self, as if we move like we are pushing something (Blazevich. A. 2010. P.196). Due to all joints acting simultaneously, the torque generated from each joint will provide an overall high amount of force (Blazevich. A. 2010. P.196). The simultaneous joint rotations of the kinetic chain often result in a straight t-line movement at the end of the chain, which allows the athlete to achieve highly accurate movements. As for in a netball pass positioning feet in a shoulder width position, moving up to the transformation of the joints moving the upper body from an up-right position forwards using the strength of the athletes abdominal. Show below is an example of the transfer of the weight through the use of the legs, transferring the weight from the back to the abdomen.

                              
                                                Image taken from:           (http://www.talkbasketball.co.uk/guides/basketball_skills_passing.html, 2007)

How to achieve accuracy in a chest pass?

Push-like Movement Pattern:

A push-like pattern can be applied to a chest pass in order to produce accuracy; however it needs to meet a range of criteria’s. This is an example of the push-like movement used in a chest pass how the symmetrical transfer of movement provides a high level of accuracy.





                                        Image Taken from: (Blazevich, 2010, p. 202.)

The movement pattern of the chest passes needs to be effective through both of the movement stages, both the closed kinetic chain and the open kinetic chain movements (Blazevich. A. 2010. P.197). As shown in the video above the chest pass’ initial movement phase is to take a step forward with their preferred foot, creating a generation of force and transfer starting at the proximal end of the kinetic chain. Therefore the strength of the netballer’s legs and hip rotation is important for this initial stage. Things like the leg press and the bench press exercises are some exercises, which will target the closed end of the kinetic chain joints. The dominant foot, which is in front, will be creating a push-like pattern, as it will be holding the stance and keeping the body grounded in order to generate and apply the force and transfer of the distal end of the body.

What is the movement and structure involved in a chest pass?

The most important aspects to achieve an accurate chest pass is the structure of the body. The position of the hips and shoulder trunk is crucial, as they need to be facing the desired direction. The ball will leave the hands as to where the athletes shoulders and hips are facing therefore it is important to have excessive movement in these areas of the body, which can be influenced through the exercises stated above. Therefore the strength within the hips and shoulders and abdominal can be crucial, as it will identify the amount of force you are able to apply to the ball. Studies suggest that individuals with greater relative lower body strength produce higher magnitude through the planted food allowing them to modify their positioning of their hips according to where they wanted the ball to go (Spiter T. Cochrane J. Hart N. Haff G. & Nimphius S.2013)

How to generate increase the speed and accuracy of a chest pass?

Through the extension of the shoulders, elbows, wrists and fingers all tendons within, will significantly recoil which increases the speed of the chest pass (Blazevich. A. 2010. P.197-205). As the chest pass incorporated two hands it produces a symmetrical forward-directed movement causing the ball to move in a relatively straight line (Blazevich. A. 2010. P.197-205). This is important as accuracy is netball is crucial as the court area is relatively small therefore a chest pass can easily be intercepted if the pass is not accurate. This stage of the chest pass incorporates a throw-like movement pattern, which is still performed within the push-like movement pattern. The push-like movement pattern is the initial stage of the chest-pass, which leads into the throw-like movement pattern, when the ball is being released through the extension of the upper body and distal joints of the kinetic chain.


What momentum is required to step into a chest pass?

Momentum summation of force:

Throughout the process of the chest pass the body mass will start on the back foot generating to the front foot as the arms and shoulders are extended to push the pass. Although a chest pass allows the ball to travel at a higher force and accurately, the generalisation of a push-like pattern of a pass generates a relatively low movement speed. This is subject to the shortening of the muscle movement, as the ball starts close to the chest to extend the arms to maximal extension (Blazevich. A. 2010. P.197-205). In order to create momentum to our body for the chest pass, it is initiated by the step forwards, then pushing the shoulders rapidly forwards, simultaneous with the elbows moving outwards and outwards while the hands on the ball staying close to the chest (Blazevich. A. 2010. P.197-205). From this is creates two important things, a significant amount of momentum is generated for the upper body and arms, and forwards velocity is generated. Mean while the tendons in the hands and fingers while holding the ball are rapidly stretched, while the elbows are flexed outwards causing the tendons to stretch as well (Blazevich. A. 2010. P.197-205). As shown in the example below:


                    Image taken from: (http://street-basketballss.blogspot.com.au/2012_09_01_archive.html. 2012).

This image emphasises the movement of the arms, shoulders and fingers when performing a chest pass.


How else can we use this information?

The biomechanics of a chest pass in netball it can be beneficial extended learning of other skills needed within netball, such as an over arm pass, a bounce pass or even shooting for a goal, as similar movements are produced. It could also enhance the results in a game scenario are it may improve the accuracy and speed of the ball allowing them to score easily or to keep position of the ball. As the chest pass adopts the push-like movement pattern, it can be applied to other games, which require a significant amount of accuracy and speed. The push-like throw pattern of the kinetic chain would be beneficial for coaches who are focusing on basketball shooting and or passing, as it is very similar to a netball chest pass. Throwing a discus and javelin incorporates the kinetic chain biomechanical principals, as there is rotation of the torso and accelerations of the arm. A javelin throw requires a large amount of force and power being it to be able to successfully throw it and to have an effective result.

The chest pass is commonly used in the same context as netball in basketball. However the mass of the ball is slightly heavier and the chest pass could be performed on the run, it still incorporates a pus-like movement pattern and the transfer of body wait from the back to the torso. It also includes the extension of the tendons in the shoulder, elbows and wrist generating accuracy and speed. A lot of force also can be generated from the stance of the basketball player at the time and their alignment of their hips and shoulders as their chest passes are played in a different context. This skill will always require a step forwards to exert force onto the ball as the ball is heavier and it at some stages of the game needs to cover a little more distance than what a chest pass does in netball. Using all the research conducted on the biomechanical principals required for a chest pass it could lead to improvements in all performance areas of a skill in a game. It can also have a positive impact on the athlete as it could enhance there learning of the skill resulting in a positive impact on their performance of the skill. It also allows the athlete to apply and transfer these biomechanical principals to other sports skills, as mentioned above.


Reference List:

Hatze, H. (1975). The meaning of the term "biomechanics". Journal of biomechanics, Vol.7(2), pp.189-90

International federation of netball association (2009) http://www.netball.org/ifna.aspx
Blazevich. A. (2010) Sports Biomechanics. The basics. Optimising human performance. Pp.196-205

Spiter,T.. Cochrane,J. Hart, N. Haff, G. & Nimphius, S.(2013) Effect of strength on plant foot kinetics and kinematics during a change of direction task Volume 13, Issue 6. pages 646-652


Talk Basketball. Basketball Passing. (2007) http://www.talkbasketball.co.uk/guides/basketball_skills_passing.html.

Street basketball blog. Basketball shooting techniques, fundamentals and form.  http://street-basketballss.blogspot.com.au/2012_09_01_archive.html. (2012).