Abstract
BackgroundThe objective measurement of the mechanical component and its role in chronic ankle instability is still a matter of scientific debate. We analyzed known group and diagnostic validity of our ankle arthrometer. Additionally, functional aspects of chronic ankle instability were evaluated in relation to anterior talar drawer.MethodsBy manual stress testing, 41 functionally unstable ankles were divided as mechanically stable (n = 15) or mechanically unstable (n = 26). Ankle laxity was quantified using an ankle arthrometer. Stiffness values from the load displacement curves were calculated between 40 and 60 N. Known group validity and eta2 were established by comparing manual and arthrometer testing results. Diagnostic validity for the ankle arthrometer was determined by a 2 × 2 contingency table. The functional ankle instability severity was quantified by the German version of the Foot and Ankle Ability Measure (FAAM-G). Stiffness (40–60 N) and FAAM-G values were correlated.ResultsMechanically unstable ankles had lower 40–60 N stiffness values than mechanically stable ankles (p = 0.006 and <0.001). Eta for the relation between manual and arthrometer anterior talar drawer testing was 0.628. With 5.1 N/mm as cut-off value, accuracy, sensitivity, and specificity were 85%, 81%, and 93%, respectively.The correlation between individual 40–60 N arthrometer stiffness values and FAAM-G scores was r = 0.286 and 0.316 (p = 0.07 and 0.04).ConclusionsIn this investigation, the ankle arthrometer demonstrated a high diagnostic validity for the determination of mechanical ankle instability. A clear interaction between mechanical (ankle arthrometer) and functional (FAAM-G) measures could not be demonstrated.Electronic supplementary materialThe online version of this article (doi:10.1186/s13018-015-0171-2) contains supplementary material, which is available to authorized users.
Highlights
The objective measurement of the mechanical component and its role in chronic ankle instability is still a matter of scientific debate
It is generally agreed that Chronic ankle instability (CAI) (Figure 1) is an “encompassing term” covering both functional ankle instability (FAI) and mechanical ankle instability (MAI) [1,2]
The mean values of the 40–60 N stiffness analyses and for both Foot and ankle ability measure-German version (FAAM-G) subscales were highest in the FAI group and lowest in the patients (Tables 2 and 3, Figures 4 and 5)
Summary
The objective measurement of the mechanical component and its role in chronic ankle instability is still a matter of scientific debate. The term “chronic ankle instability” (CAI) was introduced in 2002 and is increasingly referenced since [1]. Acute lateral ankle sprains have to be Within the literature at this time, it is obvious that the terms CAI, FAI, and MAI are not precisely defined and were not well separated in previous studies. Even recently, these terms have been used synonymously. A systematic investigation has shown that the outcome in research is mainly affected by the definitions of CAI, FAI, and MAI [2]. More detailed analyses show that MAI and FAI interaction appears to be Lohrer et al Journal of Orthopaedic Surgery and Research (2015) 10:32
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
