Single Leg Jump for Height

An objective way to measure knee extensor performance capacity on each leg.

Table of Contents

• What is a Single Leg Jump for Height test?
• Test Instructions and Demonstration
• What do the metrics mean?

What is a Single Leg Jump for Height test?

Single leg jump (SLJ) testing can give practitioners an objective measure of leg power and movement quality and can be used to quantify side-to-side asymmetries, as each leg is assessed independently. SLJs are plyometric exercises that require a group of muscles to reach maximal strength in as short a time as possible. They help bridge the gap between speed and strength training.

Vertical SLJ primarily involves the knee joint structures and quadriceps musculature. Implementing the he SLJ for Height (SLJ H) test can provide practitioners with an objective measure of an athlete's side-to-side leg power, movement quality and strategies for propulsion and absorption.

Single Leg Jump for Height test instructions:

Important: The subject must face the same direction throughout the test.

Tip: Instruct the athlete to jump as high as they can

Start the Test

1. In plantiga.io, go to Record (left sidebar)
   1. From the Activity Type drop-down, select Single Leg Jump Height
   2. From the Select People drop-down, select the athlete profile(s) being tested

Check for Warnings

2. It's important to resolve all warnings before starting or data may not be recorded.
3. Click Start

Calibration

4. Instruct the athlete to stand still for 3 seconds at the start of the assessment

The Test

5. Instruct the athlete to start with both feet on the ground and hands on their hips
6. Once ready, cue the athlete to perform 3 vertical jumps on one side and then 3 vertical jumps on the other side
   1. The athlete can choose which leg to start on and can perform the jumps at whichever pace they choose.
   2. They must jump and land on the same leg

End the Test

5. Click Stop when finished
   1. (Optional) Add contextual notes
6. Choose one of the following:
   1. Done – finish and save
   2. Next – start another assessment
   3. Reset – discard the assessment

Single Leg Jump for Height Demonstration

What do the metrics mean?

Jump height asymmetry: a comparison of left vs. right max jump heights to indicate thigh muscle strength and power performance capacity.

• When combined with Single Leg Jump for Distance testing, high jump height asymmetries can indicate trainable muscle strength and power deficits between the hip (glutes & hamstrings) vs. knee (quadriceps).

Push-off asymmetry: a comparison of the left vs. right side capacity to accelerate off the ground.

• High push-off asymmetry may occur when one limb's quadriceps musculature and surrounding tissues are fatigued, weak, or unable to produce enough load to get off the ground.

Impact asymmetry: a comparison of the ability of the left vs. right to ability to absorb load when the foot hits the ground.

• High impact asymmetry may occur when landing stiffer or more abruptly on one limb than the other.