Return to sport test battery: which tests, how to standardize them and what the numbers mean

A return to sport test battery is a measurement job before it is a decision, and the measurement is where most clinics lose the value. Pick tests you can repeat, standardize the trial so the second set of numbers is comparable with the first, record both limbs and not the ratio alone, and know what your own repeat spread is before you call a 5 percent change progress. The criteria themselves are the easy part; the protocol you run them under is what makes them mean anything.

This page is for clinicians. What a patient needs to know about the same appointment, including the criteria lists and the timing evidence, is on ACL return to sport testing, and that is the page to hand over.

What a return to sport test battery measures

A battery measures four different things, and they are not interchangeable: capacity, how much force or work the limb can produce; symmetry, the operated or injured side as a proportion of the other; quality, how the task was done; and readiness, what the athlete believes about the limb.

What it does not measure is risk, and the measurement literature is blunt about that. Hegedus and colleagues (2015) ran a systematic review of the physical performance tests used around the knee, found 29 articles covering 19 tests, and compiled 6 into a best evidence synthesis: the one leg hop for distance as a single and a triple hop, the 6 m timed hop, the crossover hop for distance, the triple jump and the single leg vertical jump.

Evidence on the validity of the hop is conflicting. There is moderate evidence that the hop test responds to change during rehabilitation. Not one of those tests, the authors report, has an established figure for reliability or measurement error expressed as a minimal important change or a smallest detectable change. And no test predicts knee injury in athletes.

Their companion review covered the hip, thigh, foot and ankle, 31 articles and 14 tests, and reported that the star excursion balance test performed in three directions, anterior, posteromedial and posterolateral, appears to be the only test associated with increased injury risk (Hegedus and colleagues, 2015, part 2). That one exception is worth following to its source before you borrow its numbers. The thresholds come from a single prospective cohort of 235 high school basketball players, in which an anterior right to left reach difference greater than 4 cm carried 2.5 times the odds of a lower extremity injury, and a composite reach distance below 94% of limb length carried 6.5 times the odds in the girls, which is the subgroup that figure belongs to (Plisky and colleagues, 2006). The same part 2 review also reports strong evidence that the vertical leap and the single leg hop are not predictors of injury, which is the clearer half of the message.

Then take those two cut-offs from Plisky rather than from the review that carried them into practice, because they do not survive the trip intact. Part 2 restates the composite threshold as 94% of the opposite limb rather than of limb length, puts the odds at three-fold and 2.7-fold rather than 6.5 and 2.5, and nowhere says the composite figure came from the girls (Hegedus and colleagues, 2015, part 2). Both figures are scores normalized to limb length, so neither means anything unless your composite is calculated the way that cohort's was, which is set out in that paper's methods rather than here.

So a battery is a description of current capacity, tracked over time, used inside a shared decision. The Bern consensus describes return to sport decisions as ones clinicians, athletes and coaches make together, ideally collaboratively, and a battery is the evidence you bring to that conversation rather than the verdict you hand over. The same statement says plainly that the research evidence supporting return to sport decisions in clinical practice is scarce (Ardern and colleagues, 2016). Treating a battery as a safety clearance claims more than the evidence gives it.

Whether passing a battery lowers the risk of a second injury is unsettled, and the detail of the split matters more than the headline. The Aspetar guideline went through the four reviews that have asked the question: three found passing associated with a lower rate of graft rupture or of reinjury, one of those three finding no effect on the other knee, and one found no statistically significant association at all. The guideline notes imprecise pooled estimates and substantial heterogeneity across them, and its own summary is that it is currently not clear whether passing a battery of tests is associated with a lower risk of a second ACL injury, partly because an event that rare is close to impossible to predict with confidence (Kotsifaki and colleagues, 2023). So the honest line is not that a battery is worthless and not that it clears anyone. It describes the limb, and the evidence that passing protects it points in both directions.

Which tests, with the equipment a clinic actually has

Start from what you own. A tape measure, a stopwatch, a handheld dynamometer, a step or box, floor tape, a cone, a phone on a tripod and a validated questionnaire will run a defensible battery.

Strength is the item people assume needs a machine they do not have. Mentiplay and colleagues (2015) tested handheld dynamometry against fixed dynamometry in 30 healthy young adults and concluded that it has good to excellent reliability and validity for most measures of isometric lower limb strength and power, with concurrent validity moderate to excellent for the hip and knee, and mostly poor to good for the ankle muscles, with intraclass correlation coefficients from 0.31 to 0.79. The authors say plainly that whether this holds in clinical populations is the next question, and a clinical population is what you are measuring. A handheld device is still defensible for the knee and the hip. The ankle is where to be most careful about what you claim from it, and where a calf endurance test earns its place alongside the dynamometer.

Hop and jump tests need a tape and a flat surface with a fixed start line. Movement quality needs a camera and a repeatable camera position, and a step down to jump to squat or a double to single leg drop is enough task to see a knee collapse inward. For balance and reach work you need floor tape, a marked three-direction layout and a tape measure for limb length if you are using the star excursion pattern, which is the one test the Hegedus reviews tie to injury risk, on the high school basketball cohort above, and limb length is what the composite score is normalized against.

Pick the tests by what the sport asks. For ankle sprain the hop and reach tasks and a single leg balance task such as single leg balance with ball kicks carry more of the job than a quadriceps index does. For hamstring strain the field leaned on pain, clinical assessment and performance tests, with the lowest reinjury rates in the studies that used the Askling H-test, so an eccentric or lengthened-state test belongs in the battery (Hickey and colleagues, 2017). For shoulder dislocation the lower limb battery is the wrong template and the measures are strength, range, and a sport-specific overhead or contact task.

How do you standardize a trial so the numbers mean anything?

By writing the protocol down once and never varying it. A number from an unstandardized trial is not a weak number, it is an unusable one, because you cannot tell a real change from a change in how you ran the test.

Fix and record these before the first patient:

What to fix	Why it moves the number
Warm-up, by content and duration	A cold hop and a warm hop are different tasks
Footwear	Barefoot, trainers and cleats give different distances
Practice trials, scored trials, best or mean	Best of 3 and mean of 3 are different measures of the same athlete
Rest between trials and between tests	Fatigue carries into the next task and inflates asymmetry
Test order	Strength before fatiguing hop work, every time
Which limb first	Order effects are real and free to remove
Arm position and start line	A swinging arm buys distance the knee did not produce
What invalidates a trial	Decide in advance: a hand down, a stumble, a held landing not held
Device, setting, calibration date, tester	A different tester with a handheld device is a different instrument
Time of day	Compare like with like at retest

Then do the thing almost nobody does. Measure your own test-retest spread. Take 10 uninjured people through your battery twice, a few days apart, and look at how much the numbers move when nothing has changed. That spread is your noise floor, and until you know it you cannot say whether a 5 percent gain is progress. Ten people is a small sample and gives you a working figure rather than a published one, which still beats having no figure at all.

The reason you have to do it yourself is in the Hegedus review: none of the 6 knee tests in that synthesis has an established minimal important change or smallest detectable change. Dynamometry is better served, and Mentiplay and colleagues (2015) did calculate a standard error of measurement and a minimal detectable change, but on their devices in healthy young adults rather than on yours in patients.

Keep the raw values of both limbs in the record. The ratio on its own throws away the information you will want later.

What is a 90 percent limb symmetry index worth?

Less than its popularity suggests, and one prospective cohort shows why.

Wellsandt and colleagues (2017) followed 70 athletes in a prospective cohort, measuring quadriceps strength and 4 single leg hop tests before ACL reconstruction and again 6 months afterward, then tracked second ACL injuries for a minimum of 2 years. Forty of the 70, 57.1%, reached 90% symmetry for quadriceps strength and all of the hop tests. When the same athletes were compared instead against their own uninvolved limb as measured before surgery, which the authors call estimated preinjury capacity, only 20 of the 70, 28.6%, reached 90%. In predicting second ACL injuries, estimated preinjury capacity was more sensitive than the symmetry index, 0.818 with a 95% confidence interval of 0.523 to 0.949 against 0.273 with a 95% confidence interval of 0.010 to 0.566. Their conclusion was that symmetry indexes frequently overestimate knee function after reconstruction.

The mechanism is just arithmetic. A ratio has two sides, and the uninvolved limb drifts down across a long rehabilitation. The Aspetar guideline answers that directly by recommending that the uninvolved limb is monitored and restored as well, and that absolute values are restored, with preoperative values used where they exist (Kotsifaki and colleagues, 2023).

Where you will see a patient before an elective operation, test both limbs then. It costs one appointment and it changes the denominator for the next twelve months. Where you cannot, say in the note that the comparison is against a limb you have never measured when it was healthy.

The 90 figure is a convention, not a finding: no study established it, and it reaches practice through the decision rules that use it. The best known of those is the Delaware-Oslo cohort's, where a pass was a score above 90 on quadriceps strength, hop test symmetry and two self-reported measures of function (Grindem and colleagues, 2016). Note whose knees produced it: 106 patients who played pivoting sports, followed prospectively for 2 years after reconstruction. In that cohort 38.2% of those who failed the criteria had a reinjury against 5.6% of those who passed, and the difference did not reach statistical significance (p = 0.075), so the rule's own study supports measuring rather than the pass mark itself. It is a sensible starting point and it is not a biological threshold.

Published criteria also disagree with each other, and the Aspetar guideline alone uses three different marks for three different decisions: more than 80% symmetry to allow running, more than 90% on jump measures at discharge, and 100% isokinetic quadriceps and hamstring symmetry before a return to high demand pivoting sport (Kotsifaki and colleagues, 2023). That guideline is candid about where its own marks come from: it states there is no evidence on which progression or discharge criteria should be used, and that its proposed discharge criteria are based on the authors' clinical experience, research findings and normative data, with the criteria themselves yet to be fully validated. Which rule you used is therefore part of the result, not a footnote to it.

One further limit belongs to the hop tests specifically, and it is covered in detail on the patient page: a near symmetrical hop distance can sit on top of a knee doing well under its share of the work, because the hip and ankle make the distance up. Cleared athletes hopped 97% of the other side, give or take 4%, while the operated knee did 69% of the other knee's work during propulsion, which is the number to carry into your own testing. It was measured in 26 male athletes aged 18 to 35 playing at a high level against 23 uninjured controls, and the authors ask for caution applying it to women and other groups, so take the lesson about hop distance and leave the exact percentages where they were derived (Kotsifaki and colleagues, 2022). Measure strength separately. Never infer it from a hop, and the measurement review says the same from a different direction: the hop seems to assess a different construct from isokinetic strength altogether (Hegedus and colleagues, 2015).

Strength, hop, movement quality and psychological readiness

Four domains, four different instruments, and a battery missing one of them is usually missing the last.

Strength is dynamometry, isokinetic where you have it and handheld where you do not, reported as both limbs in absolute units and as a ratio. For hop and jump, measure distance, time and height across three to six tasks, not one, because a single task is easy to compensate on. Movement quality is video or force plate, judged against criteria you wrote down, not against an impression.

Readiness is the one that gets dropped and it is the one with instruments ready to use. The Aspetar guideline names questionnaires including the IKDC, the ACL return to sport after injury scale and the Tampa Scale of Kinesiophobia, and notes that psychological factors, fear of reinjury in particular, are the most significant contributors to not returning to sport, citing a source of its own for that rather than its own data (Kotsifaki and colleagues, 2023). Where the question is function in daily and sporting tasks and not fear, the lower extremity functional scale and the patient specific functional scale do that job, and outcome measures in physical therapy covers choosing between them and reading the change.

Running sits underneath all of this as a separate, earlier gate with its own criteria, and return to running protocols covers those by tissue.

Do you need force plates to run a battery?

No, and the reason is not budget. Better equipment improves the precision of your measurement. It does not validate the construct you are measuring, and the construct is the weaker link: no test in the Hegedus knee synthesis predicts knee injury in athletes.

Be careful how far you carry that, though, because those reviews set out to look at clinician-friendly tests and excluded force plates, timing gates and three-dimensional motion capture by their own definition. They are not evidence that instrumented measures do not predict injury. They are evidence that the tests most clinics can run do not, and that nobody has answered the question for the equipment most clinics do not have.

What a force plate or an instrumented treadmill buys you is asymmetry inside the task rather than only in the result, which is exactly the blind spot the hop distance work exposed. If you have one, use it to look at impulse, loading rate and the contribution of each phase. If you do not, a camera, a fixed camera position and written criteria will show you the knee collapsing inward, the trunk leaning away and the landing that is caught, not controlled.

Spend first on the things that reduce noise: one tester, one device, one written protocol and a known repeat spread. A cheap battery run the same way twice is worth more than an expensive one run differently.

Recording and reporting the battery

One page per patient, the same fields every time. Date, tester, device and calibration date, warm-up, footwear, the protocol version. Then for every test: both limbs in absolute units, the ratio, the number of trials and whether the figure is a best or a mean, and whether any trial was invalidated and why.

Then three lines of interpretation that a colleague can act on without you. The worst item and by how much. What was said to the patient. The retest date.

Say what the battery was compared against, and name it. Uninvolved limb at the same visit, uninvolved limb before surgery, the athlete's own preseason numbers, or published normative values for the sport. These are four different denominators and they are not equivalent, which is the whole lesson of the symmetry work above.

How do you tell a patient they did not pass?

Give them the list, not the verdict. A failed item is a training target with a date attached, and that is a more useful thing to leave an appointment with than a yes or a no.

Four sentences do it. Here is the item that is furthest off and the number. Here is what moves it, and it is usually one or two exercises, not a new program. Here is when we retest. And here is what the test can and cannot tell us, which is the sentence to say out loud instead of implying: the numbers describe the limb today, the evidence that passing lowers the risk of a second injury points both ways, and failing does not mean the surgery went wrong.

Where the shortfall is confidence, not capacity, treat the questionnaire score as a finding and not as a soft item. Where the shortfall is a surgical restriction, it is not a failed test at all and it belongs back with the operating team.

The short version

Choose tests you can repeat with the equipment you own. Write the trial protocol down, run it the same way every time, and find out what your own numbers do when nothing has changed. Record both limbs in absolute units and name the denominator. Treat 90 percent as a convention that frequently flatters the limb, not as a biological line. And bring the battery to a shared decision, not to a clearance, because no single test in this literature predicts who gets hurt and whether passing a whole battery protects a limb is still unsettled.

References

1. Hegedus EJ, McDonough S, Bleakley C, Cook CE, Baxter GD. Clinician-friendly lower extremity physical performance measures in athletes: a systematic review of measurement properties and correlation with injury, part 1. The tests for knee function including the hop tests. British Journal of Sports Medicine. 2015;49(10):642-648. https://doi.org/10.1136/bjsports-2014-094094
2. Hegedus EJ, McDonough SM, Bleakley C, Baxter D, Cook CE. Clinician-friendly lower extremity physical performance measures in athletes: a systematic review of measurement properties and correlation with injury. Part 2: the tests for the hip, thigh, foot and ankle including the star excursion balance test. British Journal of Sports Medicine. 2015;49(10):649-656. https://doi.org/10.1136/bjsports-2014-094341
3. Wellsandt E, Failla MJ, Snyder-Mackler L. Limb Symmetry Indexes Can Overestimate Knee Function After Anterior Cruciate Ligament Injury. Journal of Orthopaedic and Sports Physical Therapy. 2017;47(5):334-338. https://doi.org/10.2519/jospt.2017.7285
4. Mentiplay BF, Perraton LG, Bower KJ, Adair B, Pua YH, Williams GP, McGaw R, Clark RA. Assessment of Lower Limb Muscle Strength and Power Using Hand-Held and Fixed Dynamometry: A Reliability and Validity Study. PLoS One. 2015;10(10):e0140822. https://doi.org/10.1371/journal.pone.0140822
5. Kotsifaki R, Korakakis V, King E, et al. Aspetar clinical practice guideline on rehabilitation after anterior cruciate ligament reconstruction. British Journal of Sports Medicine. 2023;57(9):500-514. https://doi.org/10.1136/bjsports-2022-106158
6. Kotsifaki A, Whiteley R, Van Rossom S, et al. Single leg hop for distance symmetry masks lower limb biomechanics: time to discuss hop distance as decision criterion for return to sport after ACL reconstruction? British Journal of Sports Medicine. 2022;56(5):249-256. https://doi.org/10.1136/bjsports-2020-103677
7. Hickey JT, Timmins RG, Maniar N, Williams MD, Opar DA. Criteria for Progressing Rehabilitation and Determining Return-to-Play Clearance Following Hamstring Strain Injury: A Systematic Review. Sports Medicine. 2017;47(7):1375-1387. https://doi.org/10.1007/s40279-016-0667-x
8. Ardern CL, Glasgow P, Schneiders A, et al. 2016 consensus statement on return to sport from the First World Congress in Sports Physical Therapy, Bern. British Journal of Sports Medicine. 2016;50(14):853-864. https://doi.org/10.1136/bjsports-2016-096278
9. Grindem H, Snyder-Mackler L, Moksnes H, Engebretsen L, Risberg MA. 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):804-808. https://doi.org/10.1136/bjsports-2016-096031
10. Plisky PJ, Rauh MJ, Kaminski TW, Underwood FB. Star Excursion Balance Test as a predictor of lower extremity injury in high school basketball players. Journal of Orthopaedic and Sports Physical Therapy. 2006;36(12):911-919. https://doi.org/10.2519/jospt.2006.2244

Written and checked by the PocketPhysio editorial team. Last updated 2026-10-24.