The Dial Test assesses external tibial rotation to help evaluate possible posterolateral corner involvement and rotational knee instability. A positive result may increase suspicion of PLC-related laxity but does not confirm structural injury on its own.

Introduction

Rotational knee instability can occur following traumatic sporting injuries involving twisting, hyperextension or direct force.

The Dial Test compares tibial external rotation between sides at different knee flexion angles to help assess posterolateral knee stability.

It is commonly used alongside:

• Posterior Drawer Test
• Lachman Test
• Pivot Shift Test
• overall ligament assessment

A positive result may suggest posterolateral corner involvement, particularly when excessive external rotation is present compared to the opposite side.

Quick Summary

Test name: Dial Test
Body region: Knee
Purpose: Assess posterolateral corner and rotational instability
Positive finding: Increased external tibial rotation compared to the opposite side
Negative finding: Symmetrical rotation with firm control
Best used with: Posterior Drawer and ligament testing
Key limitation: Requires careful side-to-side comparison

What Is the Dial Test?

The Dial Test assesses rotational movement of the tibia relative to the femur.

The test compares external tibial rotation at:

• 30 degrees knee flexion
• 90 degrees knee flexion

Differences in rotation may help identify posterolateral or combined ligament involvement.

Why It Is Used

The test may help:

• assess rotational knee instability
• evaluate possible PLC involvement
• identify abnormal external tibial rotation
• support complex knee injury assessment reasoning

It is commonly used after:

• contact knee injuries
• hyperextension injuries
• twisting trauma
• multi-ligament injury suspicion

What It Assesses

The Dial Test assesses:

• rotational knee laxity
• posterolateral corner stability
• external tibial rotation asymmetry
• combined ligament involvement patterns

It does not identify exact structural damage or confirm ligament rupture on its own.

Who It Is Useful For

This test may be useful for:

• sports rehabilitation practitioners
• exercise professionals
• strength and conditioning coaches
• sports medicine settings
• movement assessment professionals

When to Use This Test

Use when there is:

• rotational instability
• knee giving-way sensations
• suspected PLC injury
• complex knee trauma
• instability during direction change movements

When Not to Use or When to Be Cautious

Use caution with:

• acute swelling
• severe pain
• suspected fracture
• recent surgery
• inability to tolerate prone positioning

Stop testing if:

• pain becomes severe
• guarding prevents testing
• symptoms rapidly worsen

Equipment Required

Treatment table
Pain scale
Measurz recording workflow

Step-by-Step Protocol / Practice

Setup

Position the client prone on a treatment table.

Client Position

• Knees flexed to either 30 or 90 degrees
• Hips neutral
• Feet relaxed

Examiner/Professional Position

Stand at the end of the table facing the feet.

Hand Placement

Grip both feet or ankles evenly.

Stabilisation

Stabilise the thighs against the table where required.

Movement or Force Direction

Apply external rotational force to both lower legs simultaneously.

Compare:

• external rotation angle
• end feel
• side-to-side differences
• symptom response

Repeat at:

• 30 degrees flexion
• 90 degrees flexion

Instructions

Ask the client to:

• remain relaxed
• report pain or instability sensations
• avoid resisting movement

Positive Finding

A positive Dial Test may include:

• increased external rotation on one side
• rotational asymmetry
• soft or uncontrolled end feel
• instability sensation

Negative Finding

A negative finding involves:

• symmetrical rotation
• firm rotational control
• no instability symptoms

Stopping Criteria

Stop if:

• pain becomes severe
• guarding prevents assessment
• symptoms significantly worsen

Safety Notes

Use slow, controlled movement and avoid aggressive rotational force.

Positive and Negative Test Interpretation

A positive Dial Test may suggest:

• posterolateral corner involvement
• rotational knee laxity
• combined ligament injury patterns

Interpretation may vary depending on:

• amount of rotational difference
• knee flexion angle tested
• associated instability findings

Greater asymmetry at:

• 30 degrees may suggest PLC involvement
• both 30 and 90 degrees may suggest combined PLC and PCL involvement

A negative test may reduce suspicion of significant rotational laxity, but it does not fully exclude less severe instability patterns.

The test does not confirm ligament rupture on its own.

Sensitivity, Specificity and Diagnostic Accuracy

High-quality diagnostic accuracy evidence for the Dial Test remains limited compared to more commonly used ACL assessments.

Condition or presentation: suspected PLC or combined ligament injury
Population: individuals with knee instability or traumatic knee injury
Test variation: prone Dial Test at 30 and 90 degrees
Reference standard: MRI, surgical findings or multi-ligament assessment
Sensitivity: variable across studies
Specificity: variable across studies
Positive likelihood ratio: limited evidence available
Negative likelihood ratio: limited evidence available
Key limitations: examiner interpretation, rotational variability and low-volume research

The Dial Test is generally used as part of a broader multi-ligament knee assessment rather than as a standalone test.

Reliability and Validity

Reliability improves with:

• consistent knee positioning
• equal rotational force application
• careful side-to-side comparison

Validity is stronger when combined with:

• mechanism of injury
• posterior instability findings
• functional instability symptoms
• additional ligament testing

Common Errors and Limitations

Common errors include:

• unequal rotational force
• inconsistent knee flexion angles
• poor side comparison
• excessive force application
• over-interpreting minor asymmetries

Limitations include:

• limited standalone diagnostic evidence
• dependence on examiner experience
• rotational variability between individuals

Practical Applications

The Dial Test may help:

• assess rotational knee instability
• guide referral decisions
• support multi-ligament assessment reasoning
• monitor stability changes over time
• contribute to return-to-sport assessment discussions

How to Record This in Measurz

Record:

• test name
• side tested
• knee flexion angle used
• result (positive / negative / unclear)
• amount of rotational asymmetry
• end-feel quality
• pain score (0–10)
• instability sensation
• comparison side
• swelling presence
• related findings
• interpretation notes

Related Tests / Internal Links

Posterior Drawer Test
Lachman Test
Pivot Shift Test
Slocum Test
Anterior Drawer Test
Lever Sign Test

FAQs

What does the Dial Test assess?

It assesses rotational knee stability and possible PLC involvement.

What is a positive Dial Test?

Excessive external tibial rotation compared to the opposite side.

Does it diagnose a PLC injury?

No. It may suggest PLC involvement but does not confirm injury.

Why test at different knee angles?

Different angles may help identify different ligament involvement patterns.

Should it be used alone?

No. It works best with broader ligament assessment.

Key Takeaways

What does the Dial Test assess?

Rotational knee laxity and posterolateral stability.

Does it confirm ligament injury?

No. It only helps support assessment reasoning.

What does a positive result mean?

It may suggest posterolateral corner or rotational instability involvement.

What does a negative result mean?

It may reduce suspicion of major rotational laxity.

Should it be used alone?

No. It works best as part of a multi-ligament assessment.

What is the main value of the test?

Helping identify abnormal external tibial rotation after knee injury.

References

Hegedus, E. J., et al. (2018–2022). Diagnostic accuracy of knee special tests. British Journal of Sports Medicine.

Geeslin, A. G., et al. (2020–2023). Posterolateral corner knee injury assessment and management updates. American Journal of Sports Medicine.

LaPrade, R. F., et al. (2021). Clinical evaluation of posterolateral knee instability. Knee Surgery, Sports Traumatology, Arthroscopy.