Tuesday, November 26, 2013

EVERYTHING before... The Spike.


All you need to know about the Jump Approach.  

As you all know, in volleyball, the approach towards the spike is just as important as the spike itself. Different approaches have been developed over the years, and we are going to discuss how the effective and popular ‘left-right-left’ approach works at the biomechanical level. Without further delay, let's dive right into it!!! First of all, as a player you must locate the ball and determine where you are in relation to the ball. For a rough estimate of the time needed to approach the ball, you must judge the distance and speed of the ball to gauge the approximate timing (Velocity=Distance/Time). Being the volleyball fanatics that many of you are, you should be quite aware that you need to approach the ball in the forward direction as the goal of spiking is to hit the set ball forward. An effective spike is one that is fast enough so that the other team won’t have enough time to react before the ball touches the ground. However, the more advanced players will tell you that the angle at which you hit the ball is another important factor when it comes to determining your spiking prowess. These same volleyball experts will also tell you that to create an efficient spike the player needs to produce as much forward momentum as possible.




So how do you produce momentum?
For you to truly produce a devastating spike, it is no secret that you should jump as high as you can in order to maximize both your timing and power. To achieve this, you must utilize your body mass to accelerate by running fast enough to produce a large forward momentum. As you run towards the ball, your momentum is in the horizontal direction. However to lift your body from the floor, the biggest challenge is for you to transfer your horizontal momentum into the vertical plane. Moreover, you will develop kinetic energy and transfer some of it into potential energy when taking the last step before taking off to gain the necessary height (Hsieh).
By pushing your legs against the ground, the opposing ground reaction force acting on your body will propel you into the air (Newton's third law of action reaction). More specifically, this reaction force is caused by the combination of both the foot plant as well as the pushing off of the legs subsequently.

For the science-minded: Momentum (p) = Mass (m) X Velocity (v)

 So like we said earlier, if you want to increase your momentum the most conventional way would be to increase your velocity or running speed. Gaining more mass is also an option, however, too much mass may hinder things such as agility which are crucial to other aspects of the sport.

Meet the Stretch-Shortening Cycle..
The power of the jump must come from the legs as you will transfer the energy from the loading on your legs to his upper limbs. When you put load on your legs you utilize the stretching shortening cycle (Leyland) to improve your jumping capability. This benefits the player as this cycle provides an increase in the positive work of the muscles. Ultimately, this results in an energy increase as a result of the recoil of stretched muscle tissues from eccentric contraction, and the early activation which allows for the muscle to gain more tension over time. This essentially helps the player to push off the ground with more force, with the end result being a higher jumping height (Hsieh).


Did You Know: The stretch-shortening cycle is also used in other actions such as throwing a baseball or a javelin. That's when you know that a method is legitimate, when it's used in other sports! Here's proof:






Left, Right, Left Soldier!

Now is the moment you've all been waiting for, the actual approach leading towards the jump! To generate the force needed for the jump, you will take a big step with his left foot first. Taking this big step is important as it allows a faster run up that leads to a faster horizontal velocity which results in a faster release of the ball (Alexander).
The last two steps are the crucial parts of the approach as they produce the greatest amount of momentum (Hsieh).The second step is a small step with the right foot to increase the stability of the position of the body in preparation to end the stretch phase and to initiate the contraction in the stretch-shortening cycle.
During the last step, the left foot is in a position where the toes are facing the sideline which allows the leg to effectively act as a ‘brake’ of forward momentum and to get into a position that leads to trunk rotation at takeoff (Alexander). Also, the final step assists with trunk rotation during the takeoff phase. This rotation is associated with an increase in shoulder extension that produces a faster arm swing in a more efficient manner. As the player is about to take off, he must slow down to stay balanced. In addition, conservation of momentum states that he will transfer that momentum by extending his legs.


Remember Balance is still Key.
Balance is a key component in order to maximize how much force you can recruit while being stable enough to focus mainly on your movement and avoid wasting energy to regain balance. The momentum has to be relative, as you wouldn't want to have a momentum where you cannot keep the centre of mass within the base of support. Trust us on this, it's not pretty. In this technique, the base of support is larger compared with other approaches as you would have a larger stagger between your legs as well as a line of gravity that is significantly more stable (Ciapponi).





It's All in the Arms.
The swinging arm movement is important as well as it contributes to the overall velocity of the body’s center of gravity. To demonstrate the arm movement, the arm is initially left behind the body in a hyperextended position to prime for the most optimal forward position when the arms are swung forward, upward then downward. Moreover, when the arms are experiencing an upward acceleration, the arms push against the inferior parts of the body which increases the downward force created on the floor; which create a higher ground reaction force acting on the player.
The application of generating as much vertical momentum is important as the instant velocity at take-off will dictate the max height of centre of mass as the player leaves the ground (Bobbert et al., 1996; Bobbert & “Knoek" Van Soest, 2001; Dapena, 2000; Harman et al., 1990).

So hopefully this blog helped you, we know that it's a bit of the scientific side. However, we here at "All about the Spike" believe that it was necessary for you fanatics to fully appreciate and understand the spike. Our goal is to provide those who are passionate about volleyball with the technicalities which will help you improve your game. Hopefully you enjoyed this piece and stay tuned for our next part about..... THE ACTUAL SPIKE!!!!






References

          Ciapponi, Teri M., Erin J. McLaughlin, and Jackie L. Hudson. "The volleyball approach: An exploration of balance." Proceedings of the XIIIth International Symposium on Biomechanics in Sports. Thunder Bay, Ontario, Canada: Lakehead University. 1996. 

Alexander, Marion, et al. "An Analysis of the Volleyball Jump Serve." Sport Biomechanics Lab University of Manitoba (2010).                                       
 
Hsieh, C. T. (2006). Biomechanical and pedagogical analysis of the volleyball spike jump. (Order No. 3280676,University of Northern Colorado). ProQuest Dissertations and Theses, , 114. Retrieved from http://search.proquest.com.proxy.lib.sfu.ca/docview/305297213?accountid=13800.(305297213).

Photos:

http://deadspin.com/5505804/your-ferocious-middle+school-volleyball-spike-of-the-day

http://funny-fun-fun.com/lols/all-we-need-is-balance-funny-pictures/

http://biomechanics101.wordpress.com/2012/04/16/pitching-a-shutout/

Video: 

http://www.youtube.com/watch?v=FMtUqoxfR50













1 comment:

  1. Do you have access to the Hsieh, C. T. (2006). Biomechanical and pedagogical analysis of the volleyball spike jump thesis? I would very much like to read it. Thanks

    ReplyDelete