Silfversköid test

The Silfverskiöld Test, first described by Nils Silfverskiöld¹, is a clinical method used to identify isolated gastrocnemius contracture. This is important in the evaluation of patients with foot and ankle pathologies, as tightness in the gastrocnemius may cause reduced dorsiflexion and functional limitations.

Purpose and Principle

The purpose of the Silfverskiöld Test is to differentiate between contracture of the gastrocnemius and the soleus, as well as to exclude Achilles tendon contracture.

• Principle: The gastrocnemius crosses both the knee and ankle joints, while the soleus only crosses the ankle².

• By comparing dorsiflexion with the knee extended and flexed, it is possible to determine which muscle causes the restriction.

Execution of the Test

1. The patient lies supine or sits with the knee extended

2. The physiotherapist holds the subtalar joint in a neutral position

3. The forefoot is supinated to lock the midfoot

4. Dorsiflexion is measured with the knee extended

5. The knee is then flexed to 90°, and dorsiflexion is measured again

6. Positive test: Dorsiflexion increases when the knee is flexed, indicating gastrocnemius contracture³

Interpretation and Clinical Relevance

• Restriction only with knee extended: Suggests gastrocnemius contracture

• Restriction regardless of knee position: May indicate soleus contracture or a bony block

This distinction is clinically relevant for treatment planning, particularly in cases of plantar fasciitis, Achilles tendon pathology, and other conditions affecting ankle mobility.

Evidence and Limitations

Several studies have evaluated the reliability of the Silfverskiöld Test, with mixed results.

• Intra- and inter-rater reliability has been reported as low to moderate, with ICC values ranging from 0.230 to 0.791⁴

• This suggests that although useful, the test results should be interpreted with caution and supplemented with other clinical assessments

Summary

The Silfverskiöld Test is a simple and widely used clinical maneuver for identifying gastrocnemius contracture by comparing ankle dorsiflexion in knee extension and flexion. While clinically valuable in assessing foot and ankle pathology, its reliability is variable, and results should always be confirmed with additional evaluations.

Sources:

1. SilfverskiöldN.:  Reduction of the uncrossed two-joints muscles of the leg to one-joint muscles in spastic conditions. Acta Chir Scand;1924

2. DiGiovanni CW, Kuo R, Tejwani N, et al: Isolated gastrocnemius tightness. J Bone Joint Surg Am   2002

3. Hansen ST. Functional reconstruction of the foot and ankle. Lippincott Williams & Wilkins; 2000.

4. Assessing foot Flexibility