It is not an easy process to measure vertical jump ability for leg power assessment. You need to train and master the techniques used in vertical jump before you can do it very well. There are a number of techniques, equipment and measurement methods used in vertical jump test. The results as well as the test’s interpretation can be affected by all these. Here are some techniques as well measurement methods for vertical jump.
Static Jump or Squat Jump
Vertical jump in its simplest form is done as a static jump or squat. If you are using this technique, before you jump, you should first pause at the squat’s lower level or take a stationary semi-squatting position. If you do this well, it will help you to eliminate pre-stretching of muscles or the factor of the stretch-shortening cycle. However, the result obtained will not be as high as the results other techniques will give. Without countermovement, the difference in jump height will be around 3-6 cm.
Countermovement technique
Countermovement technique is required in order to perform the vertical jump. Before jumping upward, you have to bend your knees. The essence of countermovement is to activate the stretch-shortening cycle in the muscles which build up power in the legs. However, the countermovement technique is not enough for you to jump. You still require your arm. If you don’t use the arm, it will be difficult for you to touch the wall or reach at the height you want.
However, there is a countermovement test which does not require any arm swing in order to be done. This is called the eTID VJ protocol. If you are performing this test, you have to put one of your hands on the hip and then raise the other above the head to get to the wall. Another countermovement jump test is the Bosco Countermovement jump test. Throughout the jump, the arms are kept on the hip. A touch sensitive mat is used in performing the jump.
Using the arms
It is not always desirable to use the arms during vertical jump test. This is because it adds variations owing to coordination and technique. However, the use of the arms is allowed in a good number of vertical jump test in order to make it possible for the jumper to propel upward. You will get to a very desirable height if you make use of the arm. Besides, it is almost impossible to perform some vertical jump test without arms swing. This is because the hands should be raised up to touch the vanes of the vertec or the mark on the wall.
There are several other vertical jump tests that you can perform such as the standing vertical jump tests which are done with one leg a little bit raised. You stand with one leg.
Measurement method
There are some methods used in measuring height in vertical jump. Here are some of the methods:
• measuring the flight time using timing mat
• measuring the height reached using the vertec or similar tool