Single-Leg vs Double-Leg Jump Testing for Athletes | Starke Industries

The standard double-leg countermovement jump is a great starting test. It's quick, repeatable, and tells you a lot about an athlete's lower-body power. But sport is rarely played on two legs at once. Sprinting, cutting, bounding, and most jumps in game play happen one leg at a time.

That's why many testing programs add single-leg jumps.

What double-leg jumps show

A double-leg CMJ gives jump height, force, and timing metrics for the whole movement. On dual force plates, it can also show how much each leg contributes during the jump [1].

Impellizzeri and colleagues examined a vertical jump force test for assessing bilateral strength asymmetry, and reported that it was a reliable way to measure differences between legs during a double-leg jump [1].

The limitation: in a double-leg jump, the stronger leg can compensate. An athlete can produce a solid jump height while one leg does more of the work.

What single-leg jumps add

A single-leg jump takes away that compensation. Each leg has to produce and absorb force on its own. That can make side-to-side differences easier to see. It also gives a more sport-like picture for athletes who play mostly on one leg at a time.

Common single-leg tests include:

• Single-leg countermovement jump on a force plate

• Single-leg hop for distance

• Single-leg drop jump (more advanced, and needs good landing control first)

What the research says about limb differences

Here's where care matters. It's easy to see a left-right difference and assume it's a problem. The research is more mixed than that.

Bishop, Turner, and Read published a systematic review on the effects of inter-limb asymmetries on physical and sports performance [2]. They found inter-limb strength differences may be detrimental to jumping, kicking, and cycling performance. But when asymmetries were measured in jumping tasks and compared to change-of-direction speed, findings were mixed. Importantly, all the included studies were associative. There were no randomized controlled trials [2].

What that means in practice:

• A difference between legs is information, not a diagnosis.

• A difference being associated with lower performance doesn't prove the difference causes it.

• Some differences are normal and expected, especially in sports with a dominant side.

A single-leg test does not tell you whether an athlete will get hurt. It describes how they performed on that day.

How to test consistently

Single-leg jumps are more variable than double-leg jumps, so a consistent setup is important.

1. Same warm-up every time. 2. Hands on hips to remove the arm swing. 3. Clear rules for the free leg. For example, no swinging it to generate momentum. 4. Several trials per leg, alternating legs or following a fixed order. 5. A stable landing before a trial counts.

Compare each athlete to their own previous results under the same conditions. A single test session is a snapshot. Repeated tests show the trend.

When to add single-leg testing

Not every athlete needs it on day one. Younger athletes or those new to training may need landing skills and basic strength first. For athletes in sports with lots of single-leg actions, such as sprinting, soccer, basketball, and volleyball, single-leg testing adds useful context to a baseline.

Introduce single-leg jumps once double-leg technique is consistent, and keep them as monitoring indicators—not injury labels.

Using the results in training

If one leg consistently produces less, coaches may add more unilateral work, such as split squats, step-ups, single-leg RDLs, and single-leg plyometrics. Then re-test to see if the gap changes. The goal isn't perfect symmetry. It's building capable athletes on both sides.

Questions parents ask

My athlete's legs scored differently. Should I be worried? Not on its own. Many athletes show some difference between legs, especially in sports with a dominant side. What matters is the context: the sport, the athlete's history, and how the number changes over time. If there's pain or a medical concern, that's a question for a physician or physical therapist, not a jump test.

Can single-leg testing replace a medical clearance after an injury? No. Return-to-play decisions belong to the athlete's medical team. Testing can add performance information, but it doesn't clear anyone.

Example training ideas by goal

These are general options, not a prescription:

• Building single-leg strength: rear-foot elevated split squats, step-ups, single-leg RDLs.

• Building single-leg power: single-leg box jumps, lateral bounds, and skips for height or distance.

• Building landing control: single-leg hop-and-stick drills, progressing height and distance as control improves.

Pick exercises based on the athlete's test results, sport, and training age, then re-test to see what changed.

The bottom line

Double-leg jumps show the big picture. Single-leg jumps show what each side can do on its own. Test both, interpret limb differences carefully, and use the trend over time rather than a single number.

Related reading

• Summer Off-Season Training for High School Athletes: How to Plan the Break
• Training in the Heat: Heat Illness Basics for Summer Workouts
• Squat Jump vs. Countermovement Jump: What the Difference Tells You
• countermovement jump
• baseline
• re-test
• ForceDecks

References

• Impellizzeri FM, et al. A vertical jump force test for assessing bilateral strength asymmetry in athletes. Med Sci Sports Exerc. 2007;39(11):2044–2050. https://doi.org/10.1249/mss.0b013e31814fb55c (published Nov 2007)
• Bishop C, Turner A, Read P. Effects of inter-limb asymmetries on physical and sports performance: a systematic review. J Sports Sci. 2018;36(10):1135–1144. https://doi.org/10.1080/02640414.2017.1361894 (online Aug 2, 2017)

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