Childress Squat Test

For Medical Students

What It Tests

The Childress test asks the patient to squat fully and then walk or rock in that position, which compresses the posterior horns of both menisci under load.

It tests the part of the meniscus the other tests reach least well, because full flexion is where the posterior horn is loaded.

It also tests function directly, since a patient who cannot squat has a finding whatever the cause.

How It Is Performed

Ask the patient to squat down as far as they comfortably can, with support available.

Ask them to hold the position and then to rock or waddle forwards a short distance in the squat.

Note where the pain is, whether it is at the joint line, and whether the knee catches or blocks.

Note how far they could squat before symptoms began, which is a recordable measure. 4.7.4 covers flexion assessment.

Do not persist if the patient cannot squat safely, and record the inability rather than forcing it.

What a Positive Means

Posterior joint line pain in the squat, or a catch or block, is a positive for a posterior horn problem.

Anterior pain in the squat is patellofemoral, because a deep squat loads the patellofemoral joint heavily. 4.15.9 covers it.

An inability to squat at all is a finding and needs attributing: pain, a block, stiffness or weakness are different causes with different implications.

A patient who squats fully and comfortably has made a posterior horn tear less likely, which is one of the more useful negatives in this chapter.

MRCS Level

How It Is Performed

In a viva the expected points are the full squat, the loaded rocking, the site of the pain, and the recorded depth.

The candidate should say why full flexion is used, which is that the posterior horn is loaded there and is reached poorly in a supine test. 3.6.1 covers meniscal function.

Say that the test is a functional as well as a provocative test, which is unusual in this chapter.

Say that you would not force it and would record an inability rather than a negative.

What a Positive Means

The reasoning expected is that deep flexion shifts tibiofemoral contact posteriorly and concentrates load on the posterior horn. 3.5.4 covers the effects of flexion.

That makes the squat the natural provocation for a posterior horn or root lesion, and a squatting injury is a classic mechanism for one. 4.9.9 covers roots.

It also loads the patellofemoral joint heavily, which is why attributing the pain by site is essential rather than optional.

And it loads the cartilage of the posterior condyles, which gives a third possible source in the same position. 4.17.1 covers the cartilage presentation.

How Good It Is

The Childress test is less studied than the McMurray and Thessaly tests and its reported performance is correspondingly less certain.

The honest position is that it shares the group's pattern and that its particular value is access to the posterior horn rather than superior accuracy.

Its main practical limitation is that many patients, particularly older ones and those with stiff or painful knees, cannot perform it, so it is unavailable in much of the population it would help.

That selective availability is a real limitation and is rarely stated.

No figures appear, under decision 023.

FRCS Level

How Good It Is

At decision level the squat test is useful for two things: posterior horn localisation and a functional baseline.

The posterior horn is where root tears sit, and a root tear behaves differently from a body tear because it releases hoop tension. 4.9.9 covers it.

The functional baseline matters in counselling, because a patient who cannot squat before an operation is unlikely to squat after it, and saying so early is better than discovering it late.

It is also the test most directly relevant to the activities patients with posterior horn problems complain about, which is squatting, kneeling and getting up from low seats.

Where It Misleads

The commonest error is interpreting any pain in a deep squat as meniscal, when the position loads three structures.

The second is recording a negative when the patient could not perform the test, which is a different result entirely.

The third is forcing the squat in a knee with a suspected displaced fragment or a recent repair.

And using a patient's inability to squat as evidence of a meniscal problem when it is frequently stiffness or quadriceps weakness. 4.7.7 covers contractures.

Fellowship Level

Where It Misleads

After surgery the squat is more useful as a functional measure than as a provocative test, which is the same conclusion 4.9.4 reaches for the weight bearing rotation.

A patient who regains a full painless squat after meniscal surgery has a good functional result whatever the imaging shows.

A patient who does not needs the cause separated: a new tear, a deficient meniscus, posterior cartilage damage, stiffness, or fear. 4.9.10 covers deficiency.

After a root repair the squat is specifically restricted during the protected period, because deep flexion loads the repair, so performing the test is a protocol decision. 4.20.3 covers root repair assessment.

In the degenerate knee an inability to squat is close to universal and the test therefore contributes nothing diagnostically, though it remains a useful functional record. 4.18.6 covers functional limitation.

No figure here supports these claims, under decision 023.