Single Leg Landing Assessment

For Medical Students

What It Tests

A single leg landing loads one knee with the whole body's deceleration, which is the closest a clinic room can get to the demand that injures and re-injures knees. 3.14.8 covers landing.

It tests three things at once: whether the knee tolerates the load, whether the limb controls its alignment, and whether the patient trusts the leg.

The third is not a nuisance. A patient who will not land on the leg has given information that no passive test provides. 4.22.6 covers the score built for that question.

How It Is Performed

Clear a space and ask the patient to stand on one leg, then to perform a small single leg squat, watching the knee's alignment.

If that is tolerated, ask them to hop on the spot on that leg, then to hop forwards and land.

Watch from the front for the knee falling inwards on landing, which is the finding most associated with injury risk. 4.5.7 covers dynamic alignment.

Watch from the side for the depth of knee flexion absorbing the landing, since a stiff landing avoids quadriceps loading. 4.4.3 covers that pattern.

Compare with the other leg and record which tasks each leg managed, since the comparison is the test.

What a Positive Means

A knee that falls medially on landing indicates poor control of the limb above it, which is a hip and trunk finding rather than a knee one. 4.4.5 covers that pattern.

A stiff landing with little knee flexion indicates avoidance of quadriceps loading, from pain, weakness or a cruciate deficient knee. 4.3.9 covers wasting.

An inability to land on one leg that the other manages indicates a real difference, whatever the couch examination says.

A refusal to attempt the task is a finding and should be recorded as such rather than as a test not done. 4.2.2 covers instability as a symptom.

Pain on landing points at the patellofemoral joint, the subchondral bone or the meniscus rather than at a ligament. 4.2.1 covers pain.

MRCS Level

How It Is Performed

In a viva this is the answer to how you would assess function in a knee with a normal passive examination, and the graded progression is the mark.

The expected points are the single leg stand, the single leg squat, the hop in place, the hop and land, the two viewpoints, and the comparison.

Say that you would progress through the tasks rather than start at the hardest, both for safety and because the point at which a patient stops is the measurement.

Say that you would not attempt it in an acutely injured or recently operated knee, and say why.

Say that you would record which tasks each leg managed, since a description of the tasks survives better than a label. 4.1.8 covers the record.

What a Positive Means

The reasoning expected is that landing generates a large and rapid load that the quadriceps must absorb through a controlled flexion, so any deficit in that control appears here and not in walking. 3.14.8 covers landing.

Landing also loads rotation, because the limb decelerates and rotates at once, which is why it reproduces the mechanism of non contact cruciate injury. 4.2.16 covers non contact injury.

Medial collapse of the knee on landing results from hip abductor and external rotator weakness allowing the femur to adduct and internally rotate, and it is the pattern associated with injury risk. 3.13.7 covers dynamic alignment.

A stiff landing transfers load to the joint surfaces rather than to the muscle, which is why it produces pain over time as well as reflecting avoidance. 3.3.13 covers kinematics during landing.

How Good It Is

The assessment is the most informative functional test available in a clinic room and takes less time than most of the manual tests in this section.

It is sensitive to deficits that passive tests miss and non specific about their cause, so it shows that something is wrong and prompts the rest of the examination to say what.

It is not safe in every knee, and judgement about when to use it is part of the test rather than a limitation of it.

It is better as a comparison than as an absolute, since what counts as a competent landing varies enormously between individuals. 4.4.10 covers the screening systems built on the same idea.

No figures appear for any accuracy comparison on this page, under decision 023, and the comparison is the claim being made.

FRCS Level

How Good It Is

At decision level this assessment contributes to the return to sport decision and to the question of whether a complaint is mechanical.

A patient with a competent reconstruction who cannot land on the leg has either a rotational deficit, a strength deficit or a confidence deficit, and the three have different treatments. 4.14.3 covers the first.

A patient who lands well on both legs and complains of instability is describing something the assessment has not reproduced, and that usually means a higher demand or a confidence problem. 4.4.8 covers the higher demand.

In a cruciate deficient knee being managed non operatively, the ability to land on the leg is a better measure of coping than the Lachman grade. 4.10.3 covers the chronic knee.

Medial collapse identified here is a treatable finding, and treating it is part of a rehabilitation programme rather than a reason to operate. 4.2.34 covers previous rehabilitation.

Where It Misleads

The commonest error is not attempting it, which leaves a functional question unanswered in a clinic that had time for it.

The second is attempting it in a knee where it is unsafe.

The third is reading a failure as a ligament problem, when it is more often strength, pain or control.

The fourth is treating a refusal as uninformative.

The fifth is using it as an absolute standard rather than as a comparison with the other leg.

Fellowship Level

Where It Misleads

In referred practice this assessment separates the two commonest reasons a reconstructed knee disappoints, and it does so in a corridor.

A patient who lands competently on both legs and does not trust the knee has a confidence problem, and further surgery makes it worse. 4.22.6 covers the score for it.

A patient who collapses medially or cannot land has a mechanical or a strength deficit, and the ligament examination under anaesthesia is what separates those two. 4.14.6 covers it.

In an athlete the clinic version of the task is below the demand, so a competent landing is necessary and not sufficient, and the sport's own staff see the rest. 4.23.2 covers those patients.

In a knee with patellofemoral pathology the task reproduces the pain reliably, which makes it useful diagnostically and limits its use as a functional measure in those patients. 4.2.1 covers pain.

In medicolegal work a recorded single leg task is objective and reproducible, and its absence from a record is one reason functional claims are hard to assess. 4.23.7 covers that setting.