Dogadov Anton A, Valero-Cuevas Francisco J, Servière Christine, Quaine Franck
Univ. Grenoble Alpes, CNRS, Grenoble INP, GIPSA-lab, Institute of Engineering Univ. Grenoble Alpes, Grenoble, France.
Division of Biokinesiology and Physical Therapy, Alfred E. Mann Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA.
Int J Numer Method Biomed Eng. 2025 Jul;41(7):e70068. doi: 10.1002/cnm.70068.
The extensor mechanism is a tendinous structure that plays an important role in finger function. It transmits forces from several intrinsic and extrinsic muscles to multiple bony attachments along the finger via sheets of collagen fibers. The most important attachments are located at the base of the middle and distal phalanges. How the forces from the muscles contribute to the forces at the attachment points, however, is not fully known. In addition to the well-accepted extensor medial and interosseous lateral bands of the extensor mechanism, there exist two layers of intercrossing fiber bundles (superficial interosseous medial fiber layer and deeper extensor lateral fiber layer), connecting them. In contrast to its common idealization as a minimal network of distinct strings, we built a numerical model consisting of fiber bundles to evaluate the role of multiple intercrossing fiber bundles in the production of static finger forces. We compared this more detailed model of the extensor mechanism to the idealized minimal network that only includes the extensor medial and interosseous lateral bands. We find that including bundles of intercrossing fiber bundles significantly affects force transmission, which itself depends on finger posture. We conclude that the intercrossing fiber bundles-traditionally left out in prior models since Zancolli's simplification-play an important role in force transmission and variation of the latter with posture.
伸肌机制是一种腱性结构，在手指功能中起重要作用。它通过胶原纤维片将来自几块内在肌和外在肌的力量传递到手指上的多个骨附着点。最重要的附着点位于中节和远节指骨的基部。然而，肌肉产生的力量如何作用于附着点的力量，目前尚不完全清楚。除了伸肌机制中公认的内侧伸肌束和骨间外侧束外，还存在两层相互交叉的纤维束（浅骨间内侧纤维层和深伸肌外侧纤维层）将它们连接起来。与其通常被理想化地视为由不同弦线组成的最小网络不同，我们构建了一个由纤维束组成的数值模型，以评估多个相互交叉的纤维束在静态手指力量产生中的作用。我们将这个更详细的伸肌机制模型与仅包括内侧伸肌束和骨间外侧束的理想化最小网络进行了比较。我们发现，包括相互交叉的纤维束会显著影响力的传递，而力的传递本身又取决于手指的姿势。我们得出结论，自赞科利简化以来，传统上在先前模型中被忽略的相互交叉的纤维束在力的传递以及力随姿势的变化中起着重要作用。
