Hop tests

Original Editor - Yvonne Yap Top Contributors - Yvonne Yap and Wanda van Niekerk

Objective

A series of hop tests are routinely used in the assessment for return to sports post-injury, be it an ankle sprain or anterior cruciate ligament reconstruction. They are both functional and quantitative, allowing a measurement of power and strength of the affected to unaffected leg.

  1. Single hop test
  2. Triple hop test
  3. Crossover hop test
  4. 6 meter timed hop test

Carrying out the hop tests

Single hop test

In this test, the aim is to jump as far as possible on a single leg, without losing balance and landing firmly. The distance is measured from the start line to the heel of the landing leg. The goal is to have a less than 10% difference in hop distance between the injured limb and uninjured limb.

Triple hop test

In the triple hop test, the aim is to jump as far as possible on a single leg three consecutive times, without losing balance and landing firmly. The distance is measured from the start line to the heel of the landing leg. The goal is to have a less than 10% difference in hop distance between the injured limb and uninjured limb.

Crossover hop test

In the crossover hop test, the aim is to jump as far as possible on a single leg three consecutive times, without losing balance and landing firmly. Between each hop, the athlete has to jump across a midline, hence including side-to-side movement in this test. The distance is measured from the start line to the heel of the landing leg. The goal is to have a less than 10% difference in hop distance between the injured limb and uninjured limb.

6 meter timed hop test

In the 6 meter timed hop test, the aim is to jump as fast as possible on a single leg over a distance of 6 meters, without losing balance and landing firmly. The goal is to have a less than 10% time difference in the time taken to hop through between the injured limb and uninjured limb.

Evidence

It is recommended that an athlete has to score >90% on the tests to have a reduced risk of reinjury or injury. Quality of take-off and landing mechanics should also be assessed, on top of quantitive scores. Even with meeting the criteria for the hop tests, there is still a chance of an injury again. However, the risk of reinjury is much lower should these criteria be met[1].

The hop tests are also not used as standalone assessment in return to sports, Recent research has shown that RTS should be based on meeting a series of key performance criteria[2], rather than just timeline after an injury.

Other functional tests commonly included in return to sports include the T-test for agility, shuttle runs, beep tests. These look at a combination of power, endurance and functional movement patterns, providing a qualitative look at the specialized movements required in different sports.

On top of functional testing, other clinical tests include muscular strength, flexibility as well as range of motion of affected joint. Subjective assessments include the International Knee Documentation Committee Subjective Knee Form (IKDC 2000), which has been shown to be a valid outcome measure for knee function in patients with ACL injuries.[3]

Reliability

Single leg hop tests have shown to have a strong intra-rater reliability, with the ICC (Intraclass Correlations Coefficient) to be 0.85 for dominant and non-dominant legs). [4]

It is also a reliable and reproducible outcome measure, with ICC ranging from 0.92-0.97 for test-retest reliability for the single leg hop tests. The standard error of measurement (SEM) for the single-leg hop tests ranges from 4.61-17.74 cm, while the SEM for the 6-m hop for time test was 0.06 seconds. [5]

References

  1. Grindem H, Snyder-Mackler L, Moksnes H, et al. Simple decision rules can reduce reinjury risk by 84 % after ACL reconstruction: the Delaware-Oslo ACL cohort study. British Journal of Sports Medicine. 2016;50(13):804–8
  2. Kyritsis P, Bahr R, Landreau P, Miladi R, Witvrouw E (2016) Likelihood of ACL graft rupture: not meeting six clinical discharge criteria before return to sport is associated with a four times greater risk of rupture. British Journal of Sports Medicine 50(15):946–95
  3. Irrgang JJ, Anderson AF, Boland AL, Harner CD, Kurosaka M, Neyret P, et al. Development and validation of the international knee documentation committee subjective knee form. American Journal of Sports Medicine. 2001; 29(5):600–613.
  4. Sawle, Leanne. Intra-rater reliability of the multiple single-leg hop-stabilization test and relationships with age, leg dominance and training. International Journal of Sports Physical Therapy. 2017; 12. 190.
  5. Ross, M.D., B. Langford, and P.J. Whe- lan. Test-retest reliability of 4 single-leg horizontal hop tests. J. Strength Cond. Res. 16(4):617–622. 2002.