弹性护踝防护性能的有限元分析

Finite element analysis of elastic ankle brace performance

背景:足踝损伤是高发的运动损伤类型,常见的后遗症包括慢性足踝不稳定、足踝反复扭伤,长期发展会形成继发性关节炎,造成踝关节功能障碍。弹性护踝是常见的用于预防足踝运动损伤的护具。目的:采用有限元法预测弹性护踝对于不同运动状态下足踝内部组织应力的影响,以研究不同材料弹性护踝对于护踝防护性能的影响。方法:利用逆向工程技术,基于CT序列图像构建了健康的足踝三维有限元模型,并通过足底压力试验和前抽屉试验对模型的有效性进行验证,分别在无护踝和3种不同材料的弹性护踝作用下模拟足踝的内翻、外翻,提取足踝的整体位移以及内部组织的应力分布情况。结果与结论:①足踝有限元模型的足底压力模拟结果与试验结果有较好的一致性,前抽屉试验模拟结果与文献中的尸体实验有较好的一致性,证明了该模型具有一定的有效性:②弹性护踝可降低内翻、外翻、内旋、外旋状态下的足踝整体位移以及内部组织的峰值应力,且随材料的弹性模量增大效果增强,论证了弹性护踝的防护效果,为弹性护踝防护效果的数字化评价提供了参考。

BACKGROUND:Ankle injury is a high incidence type of sports injury.Common sequelae include chronic ankle instability and repeated ankle sprain.Long-term development will form secondary arthritis,resulting in ankle dysfunction.Elastic ankle brace is a common protective device used to prevent ankle injury.OBJECTIVE:To predict the infuence of elastic ankle brace on stress of the ankle internal tissue under different motion states using finite element method so as to the infuence of elastic ankle brace on ankle protection performance.METHODS:A healthy ankle three-dimensional finite element model was constructed using reverse engineering technology,based on CT image sequences.The plantar pressure test and anterior drawer test were utilized to validate the effectiveness of the model.Ankle varus and valgus were simulated in the absence of ankle brace and under the action of three different kinds of elastic ankle brace to extract overall ankle displacement and stress distribution of the internal tissue.RESULTS AND CONCLUSION:(1)The simulation results of plantar pressure of foot and ankle finite element model were in good agreement with the experimental results.The simulation results of anterior drawer test were in good agreement with the corpse experiment in literature,which proved the validity of this model.(2)Elastic ankle brace reduced the overall displacement of ankle and the peak stress of internal tissue in the states of varus,valgus,internal rotation and external rotation,and the effect was enhanced with the increase of the elastic modulus of the material.It demonstrates the protective effect of elastic ankle brace and provides a reference for the digital evaluation of the protective effect of elastic ankle brace.