Hop Testing Guidelines

Special Considerations:

Effusion:

Hop Testing should not be performed until Zero or Trace Effusion is seen based on established grading scale below.3,8

  • Zero: No wave produced on downstroke
  • Trace: Small wave on medial side with downstroke that does not fill the sulcus
  • 1+: Larger bulge on medial side with downstroke that fills the sulcus
  • 2+: Effusion spontaneously returns to the medial side after upstroke (no downstroke necessary) and fills the sulcus
  • 3+: So much fluid that it is not possible to move the effusion out of the medial aspect of the knee11               

ROM:

Range of Motion should be full compared to contralateral limb.3,8

Quadriceps Index (QI):

Hop Testing for return to sport should not be performed until quadriceps strength is 90% or greater compared to the uninvolved if using for return to sport criteria.12  Testing should not be performed in any circumstance until the QI is at least 70% of uninvolved.

Optimal testing conditions are to use a biodex, positioned isometrically at 60 degrees for ACL injuries.12  Patella femoral injuries and other knee testing can also be performed at 60 degrees or 90 degress with a history of patellar subluxation/dislocation.  In the presence of a PCL injury, testing should be performed at 30 degrees to minimize strain of PCL graft.  In the event of a combined ACL/PCL reconstruction, testing should be performed at 45 degrees to minimize strain on both grafts.

In the absence of a biodex or hand held dynamometer, a 1 Rep Maximum (RM), using a leg extension machine, can be calculated using repetitions of a selected weight.  The formula has been shown to be accurate in estimating 1 RM squats in high-school power lifters.13 The attached spreadsheet can be used to fill in the repetitions and repetition weight with a Quadriceps Index calculated automatically.

1 Rep Maximum = 159.9 + (.103 x Reps x Repetition Weight) + (-11.552 x reps).13

Functional Outcome Surveys:

KOS: ADLs and Sports subscales should be completed after hop testing. A score of 90% or greater is required to allow return to sport.12 

Rehabilitation Protocol:

Setup:

  • The hop test setup is 6m in length by 15 cm in width.
  • A mark should be made at each 1 meter interval for ease of measurement during testing.
  • All testers will need a measuring tape to record distance and a stop watch to record time for the 6 meter hop. 

Test Performance:

  • Begin with the uninvolved limb first
  • There should be 1 trial tests for each limb followed by 2 true tests for each limb
    • For example, if the right limb is the uninvolved limb:
      • Right trial, Right test, Right test
      • Left trial, Left test, Left test
    • This should be repeated for each individual hop test as you go.
  • The order of hop tests should be as follows:
    • Single Hop: Pt. hops on one foot as far as possible; this is measured for distance
    • Cross-over Hop: Pt. performs 3 forward hops, but each time must cross over the 15cm width of the testing area.
      • Pt able to select whether they begin by hopping medially or laterally, but must remain consistent throughout trials and between sides.
    • Triple Hop: Pt hops forward three times consecutively on one limb; this is measured for distance
    • Timed Hop: Pt hops forward as quickly as they can on one foot for the entire 6 meter distance.
  • The diagram below shows how each hop should be performed          

  • Hops are measured by starting with the great toe behind the 0cm mark and by marking the location of the heel at the landing point.
  • Subjects are allowed a rest break between hops trials if necessary (no greater than 30 sec) and between each type of hop test (up to 2 minutes)

The hop test must be repeated if the following occur:

  • For distance hops, the landing is maintained for less than 2 seconds.
  • An unsuccessful hop is classified by:
    • Touching down the contralateral limb
    • Touching down of either upper extremity
    • Loss of balance
    • Additional hop on landing
    • Using any other object to maintain balance

Results:

  • An average of the two true tests for each limb should be calculated to determine the ultimate score.
  • The average scores for each limb on each hop test should be compared to determine how the involved limb compares to the uninvolved.
  • Calculations:
    • For the distance hops: (involved average score/uninvolved average score) x100%
    • For the timed hop: (uninvolved average score/involved average score)x100%

Passing Criteria:

  • Involved side must be greater than or equal to 90% of the uninvolved side for each individual hop test.
  • No giving way, increased effusion, or increased pain.

Re-Testing:

  • If a patient has 1 of 4 hop tests that they do not achieve 90% or > they may re-do ONLY 1 test using the same guidelines for application as above.
  • Scoring and passing criteria remain the same as the original test

References:

  1. Ingram JG, Fields SK, Yard EE, et al. Epidemiology of knee injuries among boys and girls in US high school athletics. Am J Sports Med. June 2008;36(6):1116-22.
  2. Logerstedt D, Grindem H, Lynch A et al. Single-legged hop test as predictors of self-reported knee function after anterior cruciate ligament reconstruction. Presented at AOSSM. July 2012.
  3. Reid A, Birmingham TB, Stratford PW, et al. Hop testing provides a reliable and valid outcome measure during rehabilitation after anterior cruciate ligament reconstruction. Physical Therapy. March 2007;87(3):337-349.
  4. Brosky JA, Nitz AJ, Malone TR, et al. Intrarater reliability of selected clinical outcome measures following anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther. 1999;29:39–48.
  5. Kramer JF, Nusca D, Fowler P, Webster-Bogaert S. Test-retest reliability of the one-leg hop test following ACL reconstruction. Clin J Sport Med. 1992;2:240–243.
  6. Hopper DM, Goh SC, Wentworth LA, et al. Test-retest reliability of knee rating scales and functional hop tests one year following anterior cruciate ligament reconstruction. Physical Therapy in Sport. 2002;3:10–18.
  7. Hamilton RT, Shultz SJ, Schmitz RJ, et al. Triple-hop distance as a valid predictor of lower limb strength and power. J Athl Train. March 2008;43(2):144-51.
  8. Fitzgerald GK, Lephart SM, Hwang JH, et al. Hop tests as predictors of dynamic knee stability. J Orthop Sports Phys Ther. 2001;31(10):588-97.
  9. Sernert N, Kartus J, Kohler K, et al. Analysis of subjective, objective, and functional examination tests after anterior cruciate ligament reconstruction. A follow-up of 527 patients. Knee Surg Sports Traumatol Arthrosc. 1999;7:160-165.
  10. Risberg MA, Holm I, Tjomsland O, et al. Prospective study of changes in impairments and disabilities after anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther. 1999;29:400-412.
  11. Sturgill LP, Snyder-Mackler LS, Manal TJ, et al. Interrater Reliability of a Clinical Scale to Assess Knee Joint Effusion. J Orthop Sports Phys Ther 2009;39(12):845-849.
  12. Adams D, Logerstedt D, Hunter-Giordano A, et al. Current concepts for Anterior Cruciate Ligament Reconstruction: A Criterion-Based Rehabiliation Progression. J Orthop Sports PHys Ther. 2012;42(7):601-614.
  13. Kravitz L, Akalan C, Nowicki K. Prediction of 1 Reptition Maximum in High-School Power Lifters. Journal of Strength & Conditioning Research. 2003;17(1):167-172.