Does the Side Matter? Medial vs Lateral Ankle Dorsiflexion Measurements During the Silfverskiöld Test in Children

Isolated gastrocnemius tightness is associated with several foot conditions. The Silfverskiöld test examines for such tightness, and when assessing passive ankle dorsiflexion it is important to perform the examination with the proper technique. Several studies have reported reproducible examination techniques, yet none, to our knowledge, have evaluated whether measurement side-medial or lateral-affects dorsiflexion values. Understanding measurement consistency is crucial for clinical practice and research standardization. We have undertaken a study investigating whether this is of importance and assessed the repeatability of ankle dorsiflexion measurements.

We performed an exploratory cross-sectional examination of 145 pediatric patients (290 feet) with a 2-person 2-hand Silfverskiöld test. Masked, repeated goniometric measurements were undertaken along both the medial and lateral axis of the leg and foot.

There was a small systematic difference between medial and lateral measurements where lateral measurements were on average almost 2 degrees more in equinus. The repeatability coefficient for all repeated measurements ranged from 5.1 to 5.5 degrees. The intraclass correlation coefficient between medial and lateral measurements was excellent (ICC = 0.97).

We found a small systematic difference of 2 degrees between medial and lateral measurements that was less than the repeatability coefficient. The repeatability coefficient was 5 degrees, meaning that for ankle dorsiflexion measurements it is unlikely that a second measurement will differ more than 5 degrees. We do not believe that the statistically significant small difference between medial and lateral measurements is clinically relevant; however, it makes sense to consistently measure ankle dorsiflexion on either the medial or lateral side.