Person performing hop test after ACLR, symbolizing balanced recovery.

Hop to It! Early Rehab Test Predicts ACLR Success

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Kai Mendoza in Health & Wellness October 2026 • 4 min read.

"New research reveals how a simple hop test can predict long-term recovery after ACL reconstruction, highlighting the importance of early rehab goals."


Returning to pre-injury function, resuming desired activities, and preventing future knee instability are the primary goals following anterior cruciate ligament reconstruction (ACLR). While surgery offers hope, achieving these goals isn't always guaranteed. Clinical assessments can differentiate between those with good and poor knee function post-ACLR, but their ability to forecast long-term success remains unclear.

A recent study aimed to determine whether a combination of clinical, functional, and patient-reported measures taken six months after ACLR could predict successful outcomes two years post-surgery. This research offers valuable insights into the recovery process and can help guide rehabilitation strategies.

Researchers conducted a secondary analysis of prospectively collected data from seventy-three athletes who underwent ACLR due to acute, isolated, unilateral ACL ruptures. Participants completed follow-up testing at both 6 and 24 months after surgery. The six-month test battery included quadriceps strength symmetry (QI), 6-meter timed hop test symmetry (TimHP), Knee Outcome Survey Activities of Daily Living (KOS), and a Global Rating (GLO) scale.

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Why Hop Testing Matters

Hop testing is widely used after anterior cruciate ligament reconstruction (ACLR) to monitor rehabilitation and help determine when an athlete may return to sport. A systematic review published on October 16, 2024, examined how hop performance changes over time after ACLR using a longitudinal meta-analysis. Clinical tools commonly track single-hop, triple-hop, crossover-hop, and timed-hop results, often with an automatic limb symmetry index calculation.

The 96% Symmetry Sweet Spot: How Hop Test Scores Predict Your Future Knee Health

Person performing hop test after ACLR, symbolizing balanced recovery.

The study revealed that the test battery administered six months post-ACLR was indeed predictive of success at the two-year mark. Notably, TimHP (6-meter timed hop test symmetry) emerged as the only significant individual predictor within the battery. A cutoff score of 96% symmetry on the TimHP demonstrated optimal sensitivity and specificity.

Specifically, achieving 96% symmetry on the 6-meter timed hop test six months after ACLR was associated with almost twice the probability of a successful outcome. Conversely, failing to reach this cutoff indicated a 2.5 times lower likelihood of long-term success.

  • What does this mean for you? If you're undergoing ACLR, early rehabilitation efforts focused on achieving symmetry in hop testing could significantly improve your chances of a successful return to function.
  • Rethinking Return-to-Sport Criteria: Current return-to-sport criteria often suggest 85-90% symmetry. This research indicates those cutoffs may be too lenient.
  • Personalized Rehab: While delaying return to sport for high-risk athletes is prudent, maximizing clinical and functional measures early after ACLR remains crucial for optimizing individual outcomes.
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The Evidence Is Expanding

Recent reviews have investigated changes in hop performance over time after ACLR and the prognostic capacity of individual hop tests, hop-test batteries, and other unilateral functional tests after ACL injury. A 2025 review reports that the literature links hop-test batteries with reduced risk of graft or contralateral ACL rupture. However, the same review notes inconsistencies in how hop tests are used to assess knee function, identify injury risk, and predict rehabilitation outcomes.

Useful, Not Definitive

Clinical test batteries can distinguish people with good and poor knee function after ACL injury, but their usefulness for predicting longer-term outcomes after reconstruction was initially described as unknown. A systematic review characterized simple hop tests as easy, cheap, and quick tools that may identify individuals at higher risk of poor longer-term outcomes and help guide rehabilitation. Interpretation remains cautious because one review's study-selection, data-extraction, and quality-scoring process involved only one reviewer, creating a potential risk of bias.

Passing Tests Versus Returning

Reported return-to-sport rates after ACL reconstruction range from 63% to 65% for returning to preinjury activity, while 44% to 54% return to competition. Despite the widespread use of four single-leg hop tests in criterion-based return-to-play decisions, research has found equivocal relationships between passing hop-test criteria and successful rehabilitation outcomes. Research has also examined whether hop-test performance relates to the ACL Return to Sport Index, suggesting that physical performance and psychological readiness should be considered together.

These findings underscore the importance of incorporating objective measures like the 6-meter timed hop test into rehabilitation programs. By monitoring progress and striving for specific symmetry targets, clinicians can better guide patients toward successful long-term outcomes after ACLR.

Take Control of Your ACLR Recovery: Symmetry is Key

This study offers a compelling case for re-evaluating rehabilitation protocols and return-to-sport criteria following ACLR. The 6-meter timed hop test serves as a valuable tool for assessing progress and identifying individuals who may require more intensive intervention.

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Reading the Whole Test Battery

The 2024 systematic review and longitudinal meta-analysis evaluated hop performance after ACL reconstruction using data from multiple timepoints within the same cohort. The researchers conducted separate longitudinal meta-analyses for each hop test. They also used an exploratory bivariate analysis to examine correlations between different hop tests when studies reported multiple tests.

Beyond a Single Number

Clinicians commonly use muscle-strength tests, hop tests, and patient-reported outcomes to evaluate readiness for return to sport and reduce the risk of a second ACL injury. These tools have become central to clinical decision-making. A January 2026 perspective reports that significant challenges remain, supporting continued development of how muscle function and readiness are assessed.

Prediction Has Limits

Hop tests are commonly used to assess return to sport after ACL reconstruction. A systematic review and meta-analysis reports that it remains unclear whether they can effectively predict successful return to sport and reinjury risk. This uncertainty means hop-test results should not automatically be treated as definitive predictions of an athlete's future outcome.

Performance in Context

Athletes who sustain an ACL injury and undergo ACL reconstruction often complete testing to help guide return-to-sport decisions. A longitudinal case-control study notes that preinjury data are rarely available for comparison, limiting how post-injury performance can be interpreted against an athlete's own baseline. Separate research has examined functional outcomes and single-hop results at 6- and 12-month follow-ups after modified all-inside versus conventional hamstring autograft reconstruction.

By focusing on achieving 96% symmetry in the hop test within the first six months post-surgery, patients and clinicians can proactively influence the likelihood of a successful long-term outcome. This emphasizes the significance of early, targeted rehabilitation strategies.

Ultimately, these findings empower individuals undergoing ACLR to take a more active role in their recovery. By understanding the importance of symmetry and working diligently to achieve specific goals, patients can optimize their chances of returning to pre-injury function and enjoying a healthy, active lifestyle.

What the early test battery tells us

The result is a prediction about a defined composite outcome: knee-function scores meeting a normative threshold, return to pre-injury sports, and no second ACL injury. The association does not show that improving a test score itself produces recovery.[1]

What limits this ACLR prediction

  • The findings come from a secondary analysis of prospectively collected data, rather than a new dataset gathered for this analysis.[2]

The athletes and follow-up behind the ACLR analysis

PopulationAthletes after acute, isolated, unilateral ACL rupture who underwent ACLR[1]
DurationFollow-up testing at 6 and 24 months after reconstruction[1]
Main outcomeSuccessful outcome at 2 years, defined by IKDC normative values, return to pre-injury sports, and no second ACL injury[1]
Effect sizeTest battery predictive of 2-year success (r 2 =.307); TimHP was the only significant individual predictor (exp(b)=1.11); 96% symmetry cutoff had positive likelihood ratio 1.95 and negative likelihood ratio 0.4[1]
p-valuep=.005 for test battery; p=.018 for TimHP[1]
Times cited2[1]

What remains unresolved about hop-test prediction

  • Would the same prediction hold in people outside the studied athlete group or with different ACL injury patterns?[2]
  • How well does the timed-hop measure predict each part of the composite outcome when considered separately?[1]
  • Do hop measures add useful information when considered alongside strength, patient-reported function, and movement quality?[1] [3]

Sources

  1. Hop Test Symmetry Scores Early after Rehab Predict Successful 2 Year Outcomes of ACLR (SAGE Publications, 2017)
  2. Hop Test Symmetry Scores Early after Rehab Predict Successful 2 Year Outcomes of ACLR (pmc.ncbi.nlm.nih.gov)
  3. Measuring only hop distance during single leg hop testing is insufficient to detect deficits in knee function after ACL reconstruction: a systematic review and meta-analysis. (doi.org)

About this Article -

Written with AI assistance from published research, and reviewed by the Mystum team. See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1177/2325967117s00325, Alternate LINK

Title: Hop Test Symmetry Scores Early After Rehab Predict Successful 2 Year Outcomes Of Aclr

Subject: Orthopedics and Sports Medicine

Journal: Orthopaedic Journal of Sports Medicine

Publisher: SAGE Publications

Authors: Mathew Failla, Ryan Zarzycki, David Logerstedt, Elizabeth Wellsandt, Michael J. Axe, Lynn Snyder-Mackler

Published: 2017-07-01

Everything You Need To Know

1

What exactly is the 6-meter timed hop test, and why is it important in the context of ACL reconstruction?

The 6-meter timed hop test symmetry (TimHP) is a key metric assessed six months after Anterior Cruciate Ligament Reconstruction (ACLR). It involves measuring the symmetry between the injured and uninjured leg during a 6-meter hop. The significance lies in its ability to predict long-term success in ACLR recovery. Achieving 96% symmetry on the TimHP is associated with a higher likelihood of a successful return to function two years post-surgery. Implications include the potential to revise current return-to-sport criteria, which often use less stringent symmetry thresholds.

2

What is the significance of achieving 96% symmetry on the 6-meter timed hop test after ACL reconstruction?

The study identified that 96% symmetry on the 6-meter timed hop test (TimHP) six months post-Anterior Cruciate Ligament Reconstruction (ACLR) is a critical benchmark. Athletes achieving this level of symmetry had nearly double the chance of a successful outcome two years after surgery. Conversely, failing to meet this threshold indicated a significantly lower probability of long-term success. This highlights the need for focused rehabilitation strategies to achieve this specific symmetry target, guiding clinicians and patients toward better recovery outcomes.

3

How does this research impact rehabilitation strategies following ACL reconstruction?

While this text doesn't explicitly mention the specifics of rehabilitation strategies, it underscores the importance of early rehabilitation efforts after Anterior Cruciate Ligament Reconstruction (ACLR). The focus should be on achieving 96% symmetry in the 6-meter timed hop test (TimHP) at the six-month mark. This involves exercises and interventions designed to restore quadriceps strength symmetry (QI) and overall knee function. Personalized rehabilitation plans may include targeted exercises to address any asymmetries identified during the test, potentially leading to more successful long-term outcomes.

4

Does this study change the way we look at return-to-sport criteria?

The study indicates current return-to-sport criteria following Anterior Cruciate Ligament Reconstruction (ACLR) may be insufficient. These criteria often use less stringent symmetry thresholds, such as 85-90% symmetry. This research suggests these cutoffs could be too lenient. The finding that 96% symmetry on the 6-meter timed hop test (TimHP) is a significant predictor of success emphasizes the need for re-evaluating these criteria to ensure athletes are truly ready to return to their pre-injury activity levels, optimizing their chances of long-term success and reducing the risk of re-injury.

5

How is the 6-meter timed hop test used in assessing outcomes after ACL reconstruction?

The 6-meter timed hop test symmetry (TimHP) is used to measure symmetry, in the context of ACLR. The study uses the TimHP along with quadriceps strength symmetry (QI), Knee Outcome Survey Activities of Daily Living (KOS), and a Global Rating (GLO) scale to assess outcomes two years post-ACLR. The TimHP serves as a valuable objective measure within a rehabilitation program. Clinicians can use the 6-meter timed hop test to monitor progress and identify individuals who may require more intensive intervention, optimizing individual outcomes after Anterior Cruciate Ligament Reconstruction (ACLR).

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