Greve Christian, Killen Bryce A, Bos G J F Joyce, Houdijk Han, Moerman Sophie, Murgia Alessio
Department of Rehabilitation Medicine, University of Groningen, University Medical Center Groningen, the Netherlands; Department of Human Movement Sciences, University of Groningen, University Medical Center Groningen, the Netherlands.
Department of Movement Sciences, Human Movement Biomechanics Research Group, KU Leuven, Leuven, Belgium.
Comput Methods Programs Biomed. 2025 Oct;270:108972. doi: 10.1016/j.cmpb.2025.108972. Epub 2025 Jul 17.
Idiopathic clubfoot, primarily treated with the Ponseti method, recurs in 20-40 % of cases, often within the first two years post-treatment. This recurrence is commonly linked to imbalances in the inverting and everting muscle and ligament forces surrounding the foot, disrupting ankle-foot joint alignment during gait. This study aimed to evaluate the biomechanical factors contributing to clubfoot recurrence using advanced musculoskeletal modeling.
Experimental data, including 3D segment positions, lower limb muscle activity, and ground reaction forces, were collected from a typically developing child walking at a comfortable speed. Optimal muscle fiber lengths and tendon slack lengths of ankle-foot muscles were subsequently optimized on a lower extremity musculoskeletal model. To address the research question, maximum isometric evertor muscle strength and invertor muscle stiffness were then systematically manipulated on the musculoskeletal model. Additionally, ankle-foot joint geometry was altered to mimic progressive clubfoot recurrence. The impact of these changes on the ankle-foot joint moment balances was assessed by inverse dynamic analysis.
The musculoskeletal modelling approach was sensitive to subtle changes in muscle strength, joint stiffness, and joint geometry (10 %, 5 % and 3 degrees). In the absence of deforming inversion forces, only 30 % of normal evertor muscle strength was required to maintain typical ankle-foot kinematics. Increasing invertor muscle stiffness significantly increased evertor strength demands. An increase in inversion joint stiffness by >30 % leads to an inability of the model to maintain typical ankle-foot kinematics. Changes in ankle, subtalar, and midfoot joint alignment mimicking clubfoot recurrence further influenced muscle moment arm balances, though increasing deformity did not reduce evertor muscle moment arms compared to invertor muscle moment arms.
This study demonstrates the potential of advanced musculoskeletal modeling to uncover mechanical factors underlying clubfoot recurrence. The findings provide a foundation for incorporating patient-specific data in future research to validate clinical predictions. This approach could facilitate more personalized treatment strategies, improving long-term outcomes for children with recurrent clubfoot.
原发性马蹄内翻足主要采用庞塞蒂方法治疗，20%-40%的病例会复发，通常在治疗后的头两年内。这种复发通常与足部周围内翻和外翻肌肉及韧带力量失衡有关，在步态中破坏了踝足关节的对线。本研究旨在使用先进的肌肉骨骼模型评估导致马蹄内翻足复发的生物力学因素。
从一名以舒适速度行走的正常发育儿童收集实验数据，包括三维节段位置、下肢肌肉活动和地面反作用力。随后在下肢肌肉骨骼模型上优化踝足肌肉的最佳肌纤维长度和肌腱松弛长度。为了解决研究问题，然后在肌肉骨骼模型上系统地操纵最大等长外翻肌力量和内翻肌刚度。此外，改变踝足关节几何形状以模拟渐进性马蹄内翻足复发。通过逆动力学分析评估这些变化对踝足关节力矩平衡的影响。
肌肉骨骼建模方法对肌肉力量、关节刚度和关节几何形状的细微变化敏感（分别为10%、5%和3度）。在没有变形内翻力的情况下，仅需正常外翻肌力量的30%即可维持典型的踝足运动学。增加内翻肌刚度会显著增加外翻肌力量需求。内翻关节刚度增加>30%会导致模型无法维持典型的踝足运动学。模拟马蹄内翻足复发的踝关节、距下关节和中足关节对线变化进一步影响了肌肉力矩臂平衡，尽管与内翻肌力矩臂相比，畸形增加并未减少外翻肌力矩臂。
本研究证明了先进的肌肉骨骼建模在揭示马蹄内翻足复发潜在机械因素方面的潜力。研究结果为在未来研究中纳入患者特异性数据以验证临床预测提供了基础。这种方法可以促进更个性化的治疗策略，改善复发性马蹄内翻足儿童的长期预后。
