Single leg jumps to determine return to sports

The one-legged jump up on the spot (vertical jump) and the one-legged jump forward (horizontal jump) do not measure the same! The correlation between these two functional tests is only 0.63 - 0.71.

That's why at PHYSIO RESTART we attach such great importance to knowing exactly when we use which test and which exercise in practice.

One-legged jumps are a good indicator for assessing biomechanics during multi-directional, sport-specific activities. But not only these determine the sports return!

With jumps we can evaluate your explosiveness, but also your stability in rehabilitation in everyday life. Even for our teams, it makes sense to use these two core competencies after certain injuries of the lower extremity, so that the return to competition wont be too early. Nevertheless, I also evaluate the psychological readiness and the muscle strength, because only then is my decision reliable.

Especially the one-legged jump forward is often used in the later rehabilitation phase by physiotherapists to make a statement about the function of the knee. Although the forward jump is easier to measure, document and compare, the knee joint is actually significantly less involved in this jump or acceleration phase and thus contributes only 1/3 to the result (achieved jump distance).

If we compare the two one-legged jumps vertical and forward, we see relevant differences in terms of joint force involvement. To what extent are the hip, knee and ankle joints involved in these jumps? Male, healthy subjects were examined in a cross-sectional cohort study at the Orthopaedic Sports Clinic Aspetar, Qatar. In percentage terms, the following data were obtained with regard to power participation:

forward jump:

take off:

hip 44% knee 13% ankle 43%

landing:

huip 24% knee 65% ankle 11.4%

vertical jump:

take off:

hip 31% knee 34% ankle 34%

landing:

hip 29% knee 34% ankle 37%

Kotsifaki et al. 2021

So is our statement "you're ready to return to the sport because the one-legged long jump has improved your difference in distance compared to the side" unspecific?

We can only answer this question with YES. There are other publications that support this. For example, that of Zarro et al., who had athletes performing both tests 7.33 ± 2.05 months after a cruciate ligament injury and concluded that the vertical jump still showed deficits in knee function that the horizontal jump could not determine. In addition, a symmetry in the jumped distance does not equal a symmetry in muscle power.

Conclusion: The one-legged forward jump is mainly used to assess the functional hip and ankle ability, the one-legged vertical jump has significance about all three joints. Due to insufficient involvement of the knee in the one-legged forward jump, further tests should be added to determine the performance of the knee joint and thus return to the sport.

Thanks to @aspetar for these study results, generated in March 2019. It is worth mentioning the very small number of participants in this study population, which is also only male!

Author:

Anneke Penny

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References:

1.Hamilton, RT, Shultz, SJ, Schmitz, RJ, Perrin, DH. Triple-hop distance as a valid predictor of lower limb strength and power. J Athl Train. 2008;43:144-151.

2.Taylor, JB, Ford, KR, Nguyen, AD, Shultz, SJ. Biomechanical comparison of single- and double-leg jump landings in the sagittal and frontal plane. Orthop J Sports Med. 2016;4:2325967116655158.

3.Kotsifaki A, Korakakis V, Graham-Smith P, Sideris V, Whiteley R. Vertical and Horizontal Hop Performance: Contributions of the Hip, Knee, and Ankle. Sports Health. 2021 Mar;13(2):128-135.

4.Zarro MJ, Stitzlein MG, Lee JS, et al. Single-Leg Vertical Hop Test Detects Greater Limb Asymmetries Than Horizontal Hop Tests After Anterior Cruciate Ligament Reconstruction in NCAA Division 1 Collegiate Athletes. IJSPT. 2021;16(6):1405-1414.