Funaro Alessia, Shim Vickie, Mylle Ine, Vanwanseele Benedicte
Human Movement Biomechanics Research Group, Department of Movement Sciences, KU Leuven, Leuven, Belgium.
Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.
Sci Rep. 2025 Jan 7;15(1):1084. doi: 10.1038/s41598-024-84202-9.
The treatment of Achilles tendinopathy is challenging, as 40% of patients do not respond to existing rehabilitation protocols. These protocols neglect individual Achilles tendon (AT) characteristics, which are crucial for healing of the tendon tissue. Although prior studies suggest an optimal strain for AT regeneration (6% tendon strains), it is unclear if current protocols meet this condition. Our study aimed to analyse the impact of a selection of rehabilitation exercises on tendon strains in patients with Achilles tendinopathy, using subject-specific finite element (FE) models of the free AT. Second, this study aimed to explain the influence of muscle forces and material properties on AT strains. The 21 FE models of the AT included the following subject-specific features: geometry estimated from 3D freehand ultrasound images, Elastic modulus estimated from the experimental stress‒strain curve, and muscle forces estimated using a combination of 3D motion capture and musculoskeletal modelling. Exercises were ranked based on strain progression, starting from concentric and eccentric exercises, and going to more functional exercises, which impose a greater load on the AT. There was no significant difference between the unilateral heel drop and walking, and both exercises fell within the optimal strain range. However, when examining individual strains, it became evident that there was diversity in exercise rankings among participants, as well as exercises falling within the optimal strain range. Muscle forces notably affected strains more than material properties. Our findings indicate the importance of tailored rehabilitation protocols that account for individual morphological, material, and muscle characteristics.
跟腱病的治疗颇具挑战性，因为40%的患者对现有的康复方案没有反应。这些方案忽视了个体跟腱（AT）的特征，而这些特征对于肌腱组织的愈合至关重要。尽管先前的研究表明AT再生的最佳应变（肌腱应变6%），但目前的方案是否满足这一条件尚不清楚。我们的研究旨在使用游离AT的个体特异性有限元（FE）模型，分析一系列康复锻炼对跟腱病患者肌腱应变的影响。其次，本研究旨在解释肌肉力量和材料特性对AT应变的影响。21个AT的FE模型包括以下个体特异性特征：根据三维徒手超声图像估计的几何形状、根据实验应力-应变曲线估计的弹性模量，以及使用三维运动捕捉和肌肉骨骼建模相结合的方法估计的肌肉力量。锻炼根据应变进展进行排序，从向心和离心锻炼开始，到对AT施加更大负荷的更功能性锻炼。单足跟下降和行走之间没有显著差异，并且这两种锻炼都在最佳应变范围内。然而，在检查个体应变时，很明显参与者之间的锻炼排名存在差异，并且锻炼也落在最佳应变范围内。肌肉力量对应变的影响明显大于材料特性。我们的研究结果表明了考虑个体形态、材料和肌肉特征的个性化康复方案的重要性。
