INTRODUCTION

(Dani, 2013)

Volleyball is an indoor sport comprising of two teams with six players on each team with the main objective to force the ball onto the court on the opposition’s side (Vball.org.uk, 2015). The game was invented by William G. Morgan in Massachusetts, USA in 1895 (IpswichVC, 2015).  It was designed to be a less rough indoor sport than the recently invented basketball. Volleyball is a non-gender specific sport that has exceeded expectation and has had unprecedented growth in popularity over last decade. Volleyball has also extended into an outdoor sport becoming beach volleyball, a sport that encompasses a very similar set of rules and techniques.

There are many components involved within volleyball including running, jumping, passing, serving, blocking.  Key components of the sport have to be executed successfully in order for the team to have the best opportunity to win. The passing component encompasses three main techniques of passing; these are digging, setting and spiking.

This blog will focus on the skill of spiking and in particular from position four on the court as the skill differs slightly depending on where the skill is executed. The biomechanical principles of the volleyball spike and how they factor into the succession of the skill execution will be analysed throughout the blog. The following writings will also suggest methods of training that can improve the body physically to increase the likelihood of a positive outcome as well as addressing factors that an affect the outcome along with why it is crucial for the skill to be executed powerfully and accurately.




This blog has been completed by Maddy Anderson and Kirby Trautwein collaboratively.

DEFINITIONS & EQUATIONS

The following definitions and equations have been included within the blog to allow a novice learner in the field of biomechanics a greater basic understanding of the terminology and how they work.

Definitions

acceleration rate of change in velocity over the change in time

angular acceleration rate of change of angular velocity; equal to angular velocity per unit of time

angular displacement change in angular position or the orientation of a straight segment

angular impulse product of torque and time (torque produced over a period of time); equal to the change in angular momentum of an object

angular momentum product of the moment of inertia and angular velocity; angular analogue of linear momentum

angular velocity rate of change in angular displacement; equal to angular displacement per unit time

axis of rotation imaginary line passing through the centre of rotation; perpendicular to the plane of rotation

biomechanics field of science devoted to understanding mechanical principles in relation to biological organisms

centre of gravity point about which the sum of torques if all points weights (that is, mass × gravity) of a body equals zero; the body can balance at this point

centre of mass point about which the sum of torques of all point weights of a body would be zero if oriented perpendicular to the line of gravity

efficiency ratio of the input to output of a system; often refers to ratio of energy in to energy out

force product of mass and acceleration; induces a change in the mobile state of an object

impulse product of applied force and the time over which it is applied

impulse-momentum relationship relationship between impulse and momentum; the momentum of an object will change in proportion to the sum of applied impulses

inertia tendency for a body to remain in its present state of motion

kinetic chain linked segments of a body that move together

linear straight or curved but not circular (rotational) path

linear acceleration rate of change of linear velocity; equal to angular velocity per unit time

linear displacement change in linear position or the orientation of a straight segment

linear momentum product of the mass and linear displacement; equal to linear displacement per unit of time

linear velocity rate of change in linear displacement; equal to linear displacement per unit time

mass quantity of matter in an object

moment of inertia tendency for a rotating body to remain in its present state of motion; equal to the product of the mass if an object and its radius of gyration

moment of force (torque) the result of a force acting at a distance from a centre of rotation; rotational action of a force

Newton's Law's

First: An object will remain at rest or continue to move with constant velocity as long as the net force equals zero. 

Second: The acceleration of an object is proportional to the net force acting on it and inversely proportional to the mass of the object.

Third: For every action, there is an equal and opposite reaction.

power rate of doing work; work per unit or the product of force and velocity

push-like movement pattern pattern of movement whereby the joints linked segments extend (or flex) simultaneously; optimum pattern for high force and accuracy

radius of gyration distance from the axis of rotation to a point where the centre of mass of the object could be located without altering its rotational characteristics

recovery phase period during which an appendage is repositioned from the back to the front of the boy in preparation for the swing phase

rotation circular (non-linear) motion or motion about an axis of rotation

speed rate of change of distance, without reference to direction

swing phase period during which an appendage is repositioned from the front to the back of the body; usually associated with the application of propulsive force

throw-like movement pattern patter of movement whereby the joints of linked segments extend (or flex) in a sequential order, usually proximo-distally; optimum pattern for the attainment of high movement speeds

trajectory flight path of a projectile

translation linear motion

Equations

speed Δd/Δt

velocity (v) Δs/Δt

acceleration (a) Δv/Δt

angular velocity (ω) Δθ/Δt

angular acceleration (α) Δω/Δt or τ/I

force (F) m×a

torque (moment of force) (τ) F×d, where d is the moment arm of force, or τ = Iα

sum of moments or sum of torque (ΣM or Στ) τ_t = τ₁ + τ₂ + τ₃ ...

momentum (M) m×v

angular momentum (H or L) Iω or mk²ω

angular impulse-momentum relationship τ∙t = Iω

impulse (J) F×t or Δmv

inertia m

moment of inertia (I) Σmr² or mk²

power (P) F×v or W/t

All definitions and equations found in Blazevich's (2010) Sports Biomechanics.

QUESTIONS

Primary Question
What are the biomechanical principles that make up a powerful and accurate volleyball spike from position 4?

Secondary Questions

1. What other factors would affect the success of a volleyball spike?
2. What training could be undertaken in order to improve the success of a volleyball spike?
3. What are the benefits of having a powerful and accurate volleyball spike?

PRIMARY QUESTION ANSWER

This is an example of the full technique of a volleyball spike from position four on the court. (AcuSpike, 2015)

Run up

Foot contact with the ground of leading leg prior to the jump

The foot to ground contact of the first step (if the hitter is right handed this should be the right foot) in the run up phase of the skill should consist of contact to the ground beginning with the heel then following through to the toes. This motion of foot contact utilises the momentum of the hitter's body in order for the following leg to reach an even stand point before taking the jump, reducing likelihood of the hitter hopping instead of jumping. By utilising the body's own accumulating momentum, the power of the successive jump is increased. The contact of the heel to the ground first creates force in a downwards motion that will in return be propelled back up through the body from the ground in order to create a stronger and more powerful jump. Newton's Third Law states that every action has an equal and opposite reaction, this is the return of force into the jump from the contact of the foot to the ground prior to the jumping phase. Contacting the foot on the ground heel to toe allows the foot to be in contact with the ground for a longer time. This then allows for more speed to be gained during the run up which then transfers into more momentum in the jump. This aspect of the run up is also affected by the speed of the run up. Novice hitters have the tendency to slow their run ups reducing the force that is translated through the foot contact into the jump. For a successful spike to be executed a hitter must contact the ground with their leading leg heel first and at their top speed in relation to their run up. When angular momentum of the leg is maximised during the run-up phase, this will hopefully translate into a higher jump. Angular momentum is a function of moment of inertia and angular velocity (Magias, 2015).

Arm swing during run up

Arms start in a neutral position. With the first step the arms move slightly forward out in front of the body. With the next step the arms swing back behind the body as high as is comfortable for the hitter. They stay in this position until the hitter begins to jump. The movement of the arms slightly forward should be done softly to avoid an opposite reaction driving the body backward. However, the arms should still be moved forward to allow a large swing backwards. This swing action backwards creates more momentum for the body to move and lean forward. The arms remain up and back behind the body ready for the jumping phase.

Jump

Foot contact with the ground at the beginning of the jump

Back foot (right foot if right hand hit) contacts ground heel toe, front, foot lands only on the ball of the foot. By the time the front foot reaches the ground the back foot will also be on the ball of the foot ready for the jump. By the whole of the back foot being placed on the ground this allows it to make contact for longer. This translates into more force downwards for a higher jump up (Newton’s Third Law). Here angular momentum should also be maximised for the hitter to jump higher; angular momentum is greater when joint torque is produced over a longer period of time (Magias, 2015). So again the foot to ground contact time being longer allows for a higher jump. The front foot should land on the ball of the foot as this means the body position has to be leaning slightly more forward. This will aid in a higher vertical jump and will be further explained in the ‘body position prior to jump’ phase.

Body position prior to jump

The main reasons why this position is employed are to maintain balance, and jump higher. The feet are slightly apart to create a stable base of support and they’re at an angle to the net to encourage the same angle from the body. The body is now open to more hitting options without the risk of injury. The torso leans forward to create a lower centre of gravity for better balance and to allow the arms to swing back further. With the arms starting up further more momentum can be gained from the swing (as the swing is longer, therefore takes more time) and transferred into upwards momentum for the jump.

Motion of the arms throughout the jump

The arm swing begins with relatively straight, stretched out arms behind the body. The arms swing in a circular motion down then forward and up, still out stretched until they are above the head and parallel with the body. Starting with the arms as far back behind the body is important to create more time in the swing. This way the arms are able to accelerate more with more time which will aid in creating more vertical momentum in an upward direction and also more force; this will lead firstly to a higher jump and secondly the force can then be transferred into a harder hit. The arms move with angular momentum as they have angular velocity. The arms rotating up want to continue rotating up; creating momentum for the body in an upwards direction. By having the arms outstretched instead of close to the body they also create more torque which in conjunction with time creates a greater angular impulse; contacting the ball with a large impulse creates greater velocity therefore enabling a more successful spike.

Body position at peak of jump

The body position at the peak of the jump consists of an arched back, open shoulder, shoulders rotated to face court, legs have already been stretched back out and non-hitting arm has started to push down. The back is arched and the shoulders open to create maximum angular velocity. Opening the body up allows more time for the body to create more force and velocity. This then translates into a harder, faster hit.

This image displays the arched back at the peak of the jump. (lovedecor, 2015)

Downward movement of non-hitting arm

Pushing the arm down during the jump is done for a few reasons. The first relates to Newton’s Third Law. The arm pushes down with force to push the body up. The other is to rotate the body and transfer the downward momentum into the hitting arm for a faster hit.

Extension of legs downwards at peak of jump (to increase hang)

The legs are straightened again while in the air of the jump, this occurs for two reasons. The first can be explained with Newton’s Third Law. The legs extend down with force which pushes the body up, this then conserves vertical momentum in an upward direction gained from the jump (Magias, 2015). Secondly, extending the legs shifts the hitter’s centre of mass. The centre of mass is moving down due to the influence of gravity. Once the legs extend the upper body is essentially moving upwards. This shifts the centre of mass back up allowing the hitter to ‘hang’ in the air.

This video demonstrates the biomechanics of an optimal vertical jump that is needed to have a successful volleyball spike. Best examples come after 3:07. (bsizzle, 2014) 

Hitting Phase

Body position/rotation when arms are in ‘V’ cocked

The body position during this phase consists of opened body across the shoulders, facing the rest of the court. Both arms are up. The shoulder of the hitting arm is further away from the net than the non-hitting arm and cocked back in a ‘V’ position. The reason for this position is to allow the hitter more time and space to accelerate their arm so the ball can be hit with more force. Beginning with a body position open to most of the court also allows the player to hit with more variability without injury. The non-hitting arm moves back down before the hitting arm starts to swing. Newton’s Third Law applies to this action as bringing the arm down works in two ways; the first being body rotation. Once the front arm moves down the back shoulder is essentially forced forward to begin the swing of the hitting arm. The second force it creates is by moving the arm down it pushes the body up, this allows the body to ‘hang’ in the air longer. The movement produced from the cocked back ‘V’ position through to contact with the ball is a throw-like movement pattern as “a volleyball spike is performed with a sequential movement pattern where the proximal joints increase their velocity first and the more distal segments increase their velocity later" (Blazevich, 2010). Throw-like movement patterns attain higher velocity as they gain momentum through the production of large muscles and in this instance the body.

This image demonstrates the cocked 'v' position that the arm takes before hitting. (lovedecor, 2015)

Follow through

A follow through is important after a hit to ensure maximum force has been placed behind the ball. Following through with arm swing ensures that a maximum possible time has been spent contacting the ball (Physics of Volleyball, 2015). This enables the hitter more time to accelerate and therefore hit the ball with more force. This force and acceleration is also transferred into the ball after an effective hit. Following through will also help the hitter maintain balance upon landing as the centre of gravity has shifted back down. 

This image sequence is an example of a correct technique of a volleyball spike. (Learn Volleyball Skills, 2015)

This video displays an array of volleyball spike plays by professional athletes however, number 2 (3:32) and 15 (1:00) display the best technique demonstrations. (Epic Volleyball, 2014)

SECONDARY QUESTION ANSWERS

1.  What other factors would affect the success of a volleyball spike?

There are many factors that can affect the outcome of the volleyball spike. The main three are environmental factors, psychological factors and physiological factors. The environmental factors that affect the outcome can be dependent on where the game is held. Firstly, if a game is held outdoors the wind can affect the movement pattern of the ball decreasing the likelihood of the ball being contacted at all or change the trajectory of the balls flight path after contact with the hand. Another environmental factor is the surface that the game is played upon if the surface is uneven or too smooth or too rough the hitter can trip or decrease the speed of their run up in order to compensate for the surface and avoid injuring transferring in a less powerful serve. Thirdly, the sun can affect the hitter’s performance through detriment to the hitter's vision and their ability to see the ball. Psychological factors take affect mainly in game circumstances as a hitter can be affected by the presence of an opposition and the jeering of the competition or crowd. These factors can affect an hitter‘s confidence in their skill ability and therefore the outcome of the skill being played. Other factors that can affect a hitter's confidence, at times poor performance in the past can affect the hitter's performance in the present due to a loss of confidence from dwelling upon past experiences. Physiological factors have a great effect on the outcome of a volleyball spike, a hitter's health can be one of these physiological factors. For example, if a hitter suffers from asthma or other chronic illnesses it can affect the hitter's ability to execute the skill.

2. What training could be undertaken in order to improve the success of a volleyball spike?

Training is a key aspect in developing the power and accuracy of a volleyball spike. If a hitter is to be successful in the execution of the skill they must undergo a varying series of training to increase their abilities. Vertical jump training is critical in order for a hitter to be able to jump to the appropriate level with enough force and power that is translated into the hitting action. The skill of spiking is based on explosive activities of a quick run, jump then hit therefore power training is the most effective from of training to increase the likelihood of a successful outcome of the skill. Explosive strength training, plyometric training and ballistics training are the most suited forms of strength training to increase the outcome of the skill as they increase power in the legs and arms (Strength-and-power-for-volleyball.com, 2015). Strength-and-power-for-volleyball.com (2015) have an extensive list of plyometric exercises from low to medium intensity designed for volleyball.

(Strength-and-power-for-volleyball.com, 2015)

3.  What are the benefits of having a powerful and accurate volleyball spike?

There are many benefits of having a powerful and accurate spike as it is a skill that can be utilised to change the tempo of the game. An accurate spike can be employed to target weaker opposition players to score points or to target free spaces on the court in order to achieve the same outcome. Power is beneficial to the skill of the volleyball spike as it provides a shorter time frame for the opposition to reach the ball before it hits the ground. A more powerful spike may cause the opposition to falter in returning the ball as the force of the ball can cause the player to lose footing and in turn lose the point.

TRANSFERABLE/CONVERTIBLE INFORMATION

The kinetic chain process that is developed through the volleyball spike skill can be applied to a variety of sports and different skills within the sport of volleyball itself. The skill which the kinetic chain that has been cultivated can be adapted to the serve within volleyball primarily through the arm movements as they contain a similar action process. The spiking kinetic chain an also be adapted to the sport of tennis and in particular to the skill of the serve. As with the volleyball serve it has a similar arm action to the volleyball spike with the racket acting as an extension of the hand. The leg aspect of the kinetic chain can be adapted to a variety of skills in different sports. The basketball lay-up whilst utilising a hop not jump employs the same tactics in the foot contact with the ground in order to achieve more momentum and force throughout the jump. Other sports that have vertical jump based skills also utilise the leg kinetic chain process from a volleyball spike, including Australian Rules football and American National Football League.

REFERENCE LIST

AcuSpike,. (2015). How to Spike a Volleyball (in Slow Motion). Retrieved from https://www.youtube.com/watch?v=FMtUqoxfR50
Blazevich, A. (2010). Sports biomechanics. London: A & CB.
bsizzle,. (2014). Biomechanics Vertical Jump Presentation. Retrieved from https://www.youtube.com/watch?v=XQn929XwSq8
Dani,. (2013). Spiking1. Retrieved from https://danixoblog.files.wordpress.com/2013/03/spiking1.jpg
Epic Volleyball,. (2014). TOP 20 Best Volleyball Spikes: Mariusz Wlazły in World Championships 2014.. Retrieved from https://www.youtube.com/watch?v=vwPitnS_77M
IpswichVC,. (2015). Introduction to Volleyball. Retrieved 10 June 2015, from http://ipswichvc.org.uk/wp/wp-content/uploads/2014/07/ivc-introduction-to-volleyball.pdf
Learn Volleyball Skills,. (2015). Volleyball Hitting Techniques. Retrieved from http://learnvolleyballskills.com/wp-content/uploads/2015/03/volleyball-hitting-approach.gif
lovedecor,. (2015). Male beach volleyball player jumping up to spike ball. California, USA.. Retrieved from http://static.lovedecor.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/img_75462891.jpg
Magias, T. (2015). Week 9 Workshop: Increasing the speed of pace bowling in cricket. An application of angular kinetics and conserving angular momentum. Lecture, Flinders University.
Magias, T. (2015). Week 11 Workshop: Impulse-momentum relationship. Lecture, Flinders University.
Physics of Volleyball,. (2015). The Physics of Spiking. Retrieved 10 June 2015, from http://thephysicsofvolleyball.weebly.com/the-physics-of-spiking.html
Strength-and-power-for-volleyball.com,. (2015). Plyometric Volleyball Exercises and Jump Training. Retrieved 6 June 2015, from http://www.strength-and-power-for-volleyball.com/volleyball-exercises-plyometrics.html
Strength-and-power-for-volleyball.com,. (2015). Volleyball Conditioning. Retrieved 6 June 2015, from http://www.strength-and-power-for-volleyball.com/volleyball-conditioning.html 
Vball.org.uk,. (2015). Introduction to Volleyball. Retrieved 10 June 2015, from http://www.vball.org.uk/basicvolleyball/introduction_to_volleyball.htm