Ankle Orthopaedic Test: Silfverskiold Test

The Silfverskiöld Test compares ankle dorsiflexion with the knee extended and knee flexed to help differentiate gastrocnemius restriction from more general ankle or Achilles complex restriction. Greater dorsiflexion with knee flexion may suggest gastrocnemius contribution because the gastrocnemius crosses the knee. Recent work continues to focus on improving reproducibility of gastrocnemius contracture assessment, including prone-position modifications to improve measurement confidence.  

Introduction

A client reports limited squat depth, early heel rise, calf tightness, Achilles symptoms, plantar heel symptoms or reduced ankle dorsiflexion. You measure ankle dorsiflexion and notice restriction, but you need to understand whether knee position changes the result.

The Silfverskiöld Test helps identify whether dorsiflexion improves when the knee is flexed. This can support reasoning around gastrocnemius contribution, ankle joint restriction, soleus/Achilles complex restriction or foot position effects.

Quick Summary

Test name: Silfverskiöld Test
Body region: Ankle, gastrocnemius, soleus, Achilles complex
Purpose: Compare ankle dorsiflexion with knee extended versus knee flexed
Positive finding: Dorsiflexion improves meaningfully with knee flexion, suggesting gastrocnemius contribution
Negative finding: Dorsiflexion remains restricted in both positions, suggesting non-gastrocnemius limitation or combined restriction
Best used with: Ankle dorsiflexion ROM, weight-bearing lunge test, calf raise testing, foot posture, squat/lunge assessment and gait observation
Key limitation: Measurement reliability depends heavily on foot position, subtalar control and applied force

What Is the Silfverskiöld Test?

The Silfverskiöld Test assesses ankle dorsiflexion with the knee extended and then with the knee flexed. Because the gastrocnemius crosses the knee and ankle, knee flexion reduces gastrocnemius tension. If dorsiflexion improves with knee flexion, gastrocnemius tightness may be contributing to restriction.

If dorsiflexion does not improve with knee flexion, limitation may involve soleus, Achilles tendon, ankle joint, posterior capsule, bony restriction or measurement factors.

Why It Is Used

The test is used when ankle dorsiflexion restriction or calf tightness is relevant.

It may be helpful for clients with squat limitation, gait limitation, early heel rise, running symptoms, Achilles tendon symptoms, plantar heel pain, flatfoot-related concerns, forefoot overload or post-ankle injury restriction.

What It Assesses

It assesses the effect of knee position on ankle dorsiflexion. It does not diagnose a single pathology and does not quantify muscle stiffness perfectly.

Dorsiflexion can be influenced by gastrocnemius, soleus, Achilles tendon, ankle joint mobility, subtalar position, foot posture, pain, guarding and measurement method.

Who It Is Useful For

This test may be useful for runners, field-sport athletes, weightlifters, dancers, gym clients, children or adults with equinus-type presentation, and clients with limited ankle dorsiflexion.

When to Use This Test

Use when ankle dorsiflexion is limited and differentiating gastrocnemius contribution would influence exercise selection, mobility work or referral reasoning.

When Not to Use or When to Be Cautious

Use caution with acute ankle trauma, suspected fracture, severe Achilles pain, recent surgery, marked swelling, neurological involvement or pain that limits passive movement.

Equipment Required

Goniometer or inclinometer
Treatment table or floor space
Pain scale
Measurz recording workflow
Optional weight-bearing lunge setup

Step-by-Step Protocol / Practice

Setup

Position the client supine, prone or sitting depending on the method used. Record the method clearly.

Client position

Measure ankle dorsiflexion first with the knee extended and then with the knee flexed.

Examiner/professional position

Support the foot and lower leg so that movement is controlled.

Hand placement

Stabilise the lower leg and control the foot. Maintain a neutral subtalar position where possible.

Stabilisation

Avoid allowing the foot to pronate excessively or the midfoot to collapse, as this can falsely increase apparent dorsiflexion.

Movement or force direction

Move the ankle into dorsiflexion using consistent force, then repeat with the knee flexed.

Instructions

Ask the client to report calf stretch, ankle block, Achilles discomfort, pain location and whether symptoms are familiar.

Positive finding

A positive finding is meaningfully greater ankle dorsiflexion with the knee flexed compared with the knee extended, suggesting gastrocnemius contribution.

Negative finding

A negative or non-gastrocnemius pattern is limited dorsiflexion in both knee positions.

Stopping criteria

Stop if pain increases sharply, Achilles symptoms are provoked, guarding prevents measurement or the position is not tolerated.

Safety notes

Use consistent force and record the exact measurement method.

Positive and Negative Test Interpretation

Greater dorsiflexion with knee flexion may suggest gastrocnemius tightness because knee flexion reduces gastrocnemius tension. This can help guide calf mobility, strength and loading decisions.

Limited dorsiflexion in both knee positions may suggest soleus/Achilles complex restriction, ankle joint restriction, posterior capsule limitation, pain guarding, foot posture compensation or combined limitation.

The result is stronger when supported by weight-bearing dorsiflexion testing, gait or squat findings and symptom history.

Sensitivity, Specificity and Diagnostic Accuracy

The Silfverskiöld Test is primarily a clinical differentiation and measurement test rather than a diagnostic accuracy test with a single disease reference standard.

Condition or presentation: ankle equinus, gastrocnemius tightness or limited dorsiflexion
Population: people with suspected calf length limitation or foot/ankle conditions
Test variation: dorsiflexion measured with knee extended and knee flexed
Reference standard: no universally accepted gold standard for gastrocnemius tightness
Sensitivity: not applicable or not clearly established
Specificity: not applicable or not clearly established
Positive likelihood ratio: not available
Negative likelihood ratio: not available
Key limitations: inconsistent positioning, applied force, subtalar control, midfoot compensation and lack of a single reference standard

A recent prone-position modified Silfverskiöld Test study was designed to improve reproducibility and clinical confidence in gastrocnemius contracture assessment, highlighting that measurement method and reliability remain important issues.  

Reliability and Validity

Reliability depends on foot position, subtalar control, knee angle, applied force, measurement tool and examiner consistency. Older clinical discussions also emphasise the need for consistent technique, hindfoot correction and reproducibility.  

Validity is strongest when the test is used to compare dorsiflexion across knee positions rather than to claim a definitive structural diagnosis.

Common Errors and Limitations

Common errors include failing to control foot pronation, pushing harder in one position than the other, not measuring angles, ignoring pain, and treating the test as a diagnosis.

Limitations include measurement variability, midfoot compensation, subtalar influence, pain guarding and lack of a universal threshold for meaningful change.

Practical Applications

Use the Silfverskiöld Test to guide calf mobility, dorsiflexion intervention, squat modification, running assessment and progress tracking.

How to Record This in Measurz

Record test name, side tested, knee-extended dorsiflexion angle, knee-flexed dorsiflexion angle, difference between positions, measurement method, foot position, pain score, symptom location, end-feel, comparison side, confidence in result and reason for stopping.

Add related findings such as ankle dorsiflexion test, weight-bearing lunge, calf raise capacity, Achilles symptoms, plantar heel pain, squat depth and gait notes.

Related Tests / Internal Links

Ankle Dorsiflexion Test
Weight-Bearing Lunge Test
Single Leg Calf Raise
Thompson Test
Windlass Test
Squat Assessment
Balance and Proprioception Tests
Hop Tests

FAQs

What does the Silfverskiöld Test assess?

It compares ankle dorsiflexion with the knee extended and flexed to assess gastrocnemius contribution to dorsiflexion limitation.

What is a positive Silfverskiöld Test?

A positive finding is more ankle dorsiflexion with the knee flexed than with the knee extended.

What if dorsiflexion is limited in both positions?

That may suggest soleus/Achilles complex restriction, ankle joint limitation, pain guarding or combined restriction.

Does it diagnose a condition?

No. It helps differentiate possible contributors to limited dorsiflexion.

What should be recorded in Measurz?

Record dorsiflexion angle with knee extended and flexed, foot position, pain, end-feel and comparison side.

Key Takeaways

The Silfverskiöld Test compares ankle dorsiflexion across knee positions.
Improved dorsiflexion with knee flexion may suggest gastrocnemius contribution.
Technique consistency is essential for repeatable results.
It does not diagnose one condition on its own.
Measurz should capture both angles, method, symptoms and comparison findings.

References

Barouk, P., & Barouk, L. S. (2014). Clinical diagnosis of gastrocnemius tightness. Foot and Ankle Clinics, 19(4), 659–667.

Prone-Position Modified Silfverskiöld Test Study Group. (2026). Prone-position modified Silfverskiöld test: Feasibility and reliability. Foot & Ankle Orthopaedics. Needs verification.