Stiffness jumps (​7 Stiffness hops + 5 CMJ)

The stiffness of the lower limb can be tested in two different ways, either by stiffness hops or consecutive countermovement jumps (CMJ). ​These two jumps give information of the ability of the athlete to generate stiffness during dynamic/ballistic movement. These jumps are similar to the traditional drop jump, however, through experience we have found that less degree of injury/discomfort with these jump in comparison to drop jumps.

What does the test involve?

This is a jump testing analysis that takes place on two force plates. Therefore, each foot is on its own force plate allowing for measurements of the symmetry of force application during the jump. You will be asked to complete 7 continuous stiffness hops as well as 5 continuous CMJs on the force plates. During these jumps your force application onto the force plate will be measured. The goal for the stiffness hops is to jump as high as possible with as short as possible ground contact times whereas the goal of the 5 continuous CMJs is to jump as high as possible with the shortest possible contact time including a countermovement action for these jumps.

What will you get?

You will receive three reports (per person) after the completion of this test. These reports include a report for the stiffness hops, 5 CMJs and a comparative report of the relationships between the stiffness hops and the 5 CMJs which will give more in-depth information relating to the both the fast and slow eccentric contraction.

If you were to come for retesting or another testing session at a later stage, we will also give you an indication of the comparison between the two testing sessions. Therefore, it is possible to distinguish change over time related to either training adaptation, muscular fatigue, or injury related changes in these results.

How long will it take?

This is a very short test. If you come to the laboratory after already completing your own warm up session the testing should take between 5 and 10 minutes. If a group/team comes for testing, between 20 and 25 athletes can be tested within an hour.

What should you do/bring?

You will need to bring comfortable training clothes and shoes. Furthermore, it is suggested that you do not participate in any strenuous training 24 hours prior to the test, unless the goal of the testing is to determine the muscular fatigue induced by the training session. We also suggest that you complete a warm up session prior to attending the lab in order to obtain the maximal performance during this test session.​