A comparison of speed skating with normal and reduced ankle eversion

Abstract

Purpose: Executing the sideward skating push-off requires a skater’s full attention and capabilities. Ankle eversion (AE) occurs during the push-off with skaters of low and high skill levels. Controlling AE requires high muscle force. AE adds unnecessary stress thus fatigue is a likely consequence. A purpose for AE in speed skating has not yet been found. Ankle eversion (AE) is considered an unwanted distraction during the execution of the push-off. The first goal is to reduce AE during speed skating. Plantar and dorsal flexion is to be left unhampered. The second goal is to prove that the skating motions can be executed with reduced AE. Method: An orthosis was designed to reduce AE on the right leg only. Skaters (n=10) with low and high skill levels were recorded while skating with normal and reduced AE. Video analyses resulted in relevant angles to quantify skating motions. The tested skaters filled out a questionnaire about skating with reduced AE. Results: On average AE was reduced by 45 to 70% from approximately 13 to 4 degrees with the tested skaters. Skating motions could be executed with reduced AE. The overall rating by the tested skaters for skating with reduced AE was neutral to positive. The orthosis functioned properly but it was considered big and clumsy. Conclusion: There are no negative outcomes from the angle measurements or the questionnaire on skating with reduced AE. That is a very positive situation. An estimation of the required muscle force shows that the amount is reduced significantly when skating with reduced compared to normal AE. As a result a skater saves energy and is not distracted by AE when executing the push-off. Skating with reduced AE might have a positive influence on performance. This has not been measured. A redesign of the orthosis should be stiffer and more compact.