Vertical Jump Testing

[Guest guest]

Was: Serge and WR Vertical

Mel Siff:

<I very much doubt that these heights were achieved from a static start with

flexed knees and no use of a 'plyometric' dip.>

Kurland wrote:

<<I doubt it very much, too, since the standard protocol is with a dip, not

flexed knees. I've never seen or heard of anyone running a vertical jump

test in such a way - it would strip the test of any usefulness, I think. >>

*** Actually, there are at least two useful ways of applying the vertical

jump tests - one from a static flexed knee start and the other using the

usual ballistic dip start. You probably haven't seen these different

versions used because coaches probably don't know about all the variations of

jump testing. The difference between the two jumps can yield useful

information on one's strength deficit. There are two other versions of the

static and ballistic start tests, one using arm swing and the other without,

with details of these tests appearing on p453 of the " Supertraining "

textbook.

While we are at it, it would be instructional to examine the whole concept of

vertical jump testing. The current use of a simply ballistic dip start text

can yield only a rather limited amount of information, but if one extends the

basic tests to include different types of initial conditions, then the test

becomes more informative.

Here is the extract from " Supertraining " (2000, p453) on some of the

different types of jump test:

< This well-known test may be applied in several different ways. Invariably

it requires the subject to leap from a standing position with a preliminary

dip and touch a measuring device sideways with one's dominant hand.

Recalling the specificity of training, it is important to note that the

results of this test correlate best with conditions which are most similar to

that of the test. Therefore, it is useful to repeat the test with the

non-dominant hand or in the frontal plane with the athlete using both hands

to reach for the target. Moreover, there are several different initial condi

tions for executing this test:

1. Starting statically from an optimum knee flexed position using no arm

swing

2. Starting statically from an optimum knee flexed position using arm swing

3. Starting dynamically with an optimal knee dip using no arm swing

4. Starting dynamically with an optimal knee dip using arm swing.

The major difference between the first two methods is that jumping without

armswing is intended to focus primarily on the role played by extension of

the lower extremity and trunk, without the picture being confounded by the

use of arm momentum. The major difference between the static and dynamic

starts is that the absence of an initial sharp dip allows one to focus more

on starting strength and the role played by the contractile (actin-myosin)

component of the muscle complex, instead of the more plyometric rebound

action encouraged by the use of the dip. This can sometimes assist one in

ascertaining whether the athlete needs more strength (or functional

hypertrophy) training or more rebound, nervous system training.

It can also be helpful to perform the static tests from different initial

knee angles to obtain a profile of individual jumping characteristics. For

example, if the maximum vertical jump is attained for a fairly large knee

angle, which is generally associated with a slower overall jumping time from

start to finish of the action, then it is obvious that the athlete needs to

concentrate on modifying his range and speed of maximal strength production.

Table 8.12 provides guidelines concerning the depth of loaded knee dips.

This reveals that the dip chacteristically is deeper for heavier loads or

persons and that in all cases the pause during the dip should not last longer

than 0.25 second. Herein lies the benefit of performing push jerks or jerks

off racks with different weights as a form of supplementary plyometric

training. After all, plyometric training is of little value if it fails to

enhance adequately explosive strength or power over the range required in a

given activity. The use of drills which do not correlate strongly with the

functional needs of a given sport constitute one of the most common errors in

popular plyometric training....... >

Some other variants of the jump tests are:

A. Jumps tests from either leg (static and ballistic versions)

B. Jump tests with a run up (left and right)

C. Jump tests facing the wall or measuring device.

One should also not forget the use of broad jump tests from both a static and

a ballistic dip start. Serge also used to do these exercises. Make sure

that if you use them to land on a surface that will absorb some of the shock,

but do not use very shock absorbing surfaces for " plyometric " exercises,

since this can markedly lengthen the coupling time between eccentric and

concentric phases of the action.

Obviously, you will choose the tests which best suit your purpose, since it

is unnecessary to prescribe hosts of tests (and ballistic training drills)

which may have minimal bearing on the conditioning of your athlete.

Dr Mel C Siff

Denver, USA

Supertraining/