Influence of population variability in ligament material properties on the mechanical behavior of ankle: a computational investigation

Abstract

Biomechanical behavior of ankle ligaments varies among individuals, with the underlying mechanism at multiple scales remaining unquantified. The present probabilistic study investigated how population variability in ligament material properties would influence the joint mechanics. A previously developed finite element ankle model with parametric ligament properties was used. Taking the typical external rotation as example loading scenario, joint stability of the investigated population was consistently shared by specific ligaments within a narrow tolerance range, i.e. 62.8 ± 8.2 Nm under 36.1 ± 5.7° foot rotation. In parallel, the inherent material variability significantly alters the consequent injury patterns. Three most vulnerable ligaments and the consequent rupture sequences were identified, with the structural weak spot and the following progressive stability loss dominated by the relative stiffness among ligaments. This study demonstrated the feasibility of biofidelic models in investigating individual difference at the material level, and emphasized the importance of probabilistic description of individual difference when identifying the injury mechanism of a broad spectrum.

Keywords:

• Population variability
• ankle ligament
• biomechanics
• finite element modeling
• load sharing
• material properties

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was in part supported by the National Natural Science Foundation of China (51705276, 51278021), Tsinghua University Initiative Scientific Research Program (2019Z08QCX13), National Key R&D Program of China (2017YFE0118400), State Key Laboratory of Automotive Safety and Energy (ZZ2019-013), Young Elite Scientist Sponsorship Program by CAST (2018QNRC001).