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.
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.
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
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.
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
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.
This test may be useful for:
sports rehabilitation practitioners
exercise professionals
strength and conditioning coaches
sports medicine settings
movement assessment professionals
Use when there is:
rotational instability
knee giving-way sensations
suspected PLC injury
complex knee trauma
instability during direction change movements
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
Treatment table
Pain scale
Measurz recording workflow
Position the client prone on a treatment table.
Knees flexed to either 30 or 90 degrees
Hips neutral
Feet relaxed
Stand at the end of the table facing the feet.
Grip both feet or ankles evenly.
Stabilise the thighs against the table where required.
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
Ask the client to:
remain relaxed
report pain or instability sensations
avoid resisting movement
A positive Dial Test may include:
increased external rotation on one side
rotational asymmetry
soft or uncontrolled end feel
instability sensation
A negative finding involves:
symmetrical rotation
firm rotational control
no instability symptoms
Stop if:
pain becomes severe
guarding prevents assessment
symptoms significantly worsen
Use slow, controlled movement and avoid aggressive rotational force.
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.
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 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 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
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
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
Posterior Drawer Test
Lachman Test
Pivot Shift Test
Slocum Test
Anterior Drawer Test
Lever Sign Test
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.
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.
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.
