Functional Movement Screening

For Medical Students

What It Tests

A functional movement screen is a set of standardised tasks scored against defined criteria, designed to describe how a person moves rather than to diagnose a structure.

In a knee clinic the tasks that matter are the loaded single leg ones: the squat, the hop, the landing and the step down. 4.4.9 covers the landing.

The purpose is comparison rather than diagnosis. A screen compares a limb with the other limb, or a person with themselves over time, and it does not name a torn structure. 4.22.8 covers the patient reported scores that do something similar.

How It Is Performed

Choose a small number of tasks and perform them the same way every time, because a screen's value is entirely in its consistency.

A practical set is the double leg squat, the single leg squat, the step down, the single leg hop and the hop and land.

Score each task simply: completed well, completed with compensation, or not completed, and record which leg.

Watch for the same features in each task: the knee's alignment, the depth of flexion, the trunk's position and whether the patient hesitates.

Compare legs and record the comparison rather than an absolute score, since absolute scores vary with age, build and training. 4.4.9 covers that argument.

What a Positive Means

An asymmetry between legs on the same task indicates a real difference, and in a patient with a knee complaint it usually localises to the affected side.

Medial collapse of the knee in several tasks indicates poor proximal control rather than a knee problem. 4.4.5 covers that pattern.

Reduced depth of knee flexion across tasks indicates quadriceps avoidance, weakness, pain or a restricted range, and the passive examination separates those. 4.7.2 covers passive motion.

Hesitation without a measurable deficit is a confidence finding, and it is common after a reconstruction. 4.22.6 covers the score built for it.

A normal screen in a patient with a significant complaint means the tasks are below the demand that fails, and the assessment has to move rather than conclude. 4.4.8 covers running gait.

MRCS Level

How It Is Performed

In a viva the useful answer treats screening as a structured version of observation rather than as a test, and says what it can and cannot do.

The expected points are a small fixed task set, a simple scoring system, the same features watched in each task, and the comparison between legs.

Say that a screen does not diagnose, and say what it is for, because conflating the two is the error the question is probing.

Say that you would use it to follow a patient rather than to assess one once, since its strength is serial comparison. 4.1.8 covers the record.

Say that the published screening systems exist and that their predictive value is contested, which is an accurate statement rather than a dismissal.

What a Positive Means

The reasoning expected is that movement quality depends on strength, control, range and confidence together, so a screen measures a composite rather than any one of them. 3.14.8 covers the loading the tasks reproduce.

That composite is what fails in sport, which is why screening correlates with function better than any passive measurement does and why it localises nothing. 4.4.8 covers the higher demand.

Asymmetry is the informative part, because it removes the variation between individuals that makes absolute scores hard to interpret.

Proximal control appears repeatedly across tasks, which is why a screen often identifies a hip problem in a knee clinic. 4.4.5 covers that pattern.

How Good It Is

Screening is good at describing asymmetry and poor at predicting injury, and the second claim is where the published systems have been most criticised.

It is reproducible when the tasks and the scoring are fixed and unreproducible when they are improvised, which is a property of the protocol rather than of the idea.

It adds most in a patient whose passive examination is normal and whose complaint is functional, which is a substantial group in a knee clinic. 4.14.3 covers the diagnosis it sometimes uncovers.

It adds least in an acute knee, where the tasks cannot be performed and the diagnosis is a structural question. 4.8.7 covers that presentation.

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 screening contributes to return to sport and rehabilitation decisions and to nothing surgical, which is a clear and limited role.

A patient with a competent reconstruction and a marked asymmetry has not completed rehabilitation, and the screen is the evidence of that. 4.2.34 covers previous rehabilitation.

A patient with symmetrical competent movement and a persisting complaint is describing a demand above the screen or a confidence problem, and neither is answered by surgery. 4.22.6 covers the score for the second.

Screening also supplies a discharge criterion that is more meaningful than a time interval, which is its most practical use in a surgical clinic. 4.7.10 covers post-operative range.

Where a screen identifies proximal control failure, treating it is the intervention, and in a patient with patellofemoral complaints it is often the whole treatment. 4.4.5 covers the pattern.

Where It Misleads

The commonest error is treating a screen as a diagnostic test.

The second is improvising the tasks, which removes the only thing that makes a screen work.

The third is using an absolute score rather than the comparison.

The fourth is claiming predictive value for injury, which is contested.

The fifth is screening an acute knee, where the tasks are neither safe nor informative.

Fellowship Level

Where It Misleads

In referred practice screening is most useful as the thing that has not been done to a patient who has been investigated instead.

A patient with normal imaging, a normal examination and a knee that fails in sport frequently has a movement problem, and the screen is where it appears rather than on a further scan. 4.1.6 covers the relationship with imaging.

A patient with a marked asymmetry years after a reconstruction has an established pattern, and whether it is still modifiable is a rehabilitation judgement rather than a surgical one. 4.3.9 covers wasting.

In the elite athlete screening is already part of the environment and the surgeon's role is interpreting their data rather than generating it, which is a different relationship from the usual clinic one. 4.23.2 covers those patients.

In a hypermobile patient the tasks are performed with movement patterns that look abnormal and are normal for them, so the comparison with their own other leg is the only interpretable version. 4.23.3 covers those patients.

In medicolegal work a recorded screen is objective and is rarely available, and the absence of any functional record is the commonest gap in these assessments. 4.23.7 covers that setting.