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Functional anatomy of the Achilles tendon

Knee Surgery, Sports Traumatology, Arthroscopy volume 18, pages 638–643 (2010)Cite this article

Abstract

The Achilles tendon is the strongest and thickest tendon in the human body. It is also the commonest tendon to rupture. It begins near the middle of the calf and is the conjoint tendon of the gastrocnemius and soleus muscles. The relative contribution of the two muscles to the tendon varies. Spiralisation of the fibres of the tendon produces an area of concentrated stress and confers a mechanical advantage. The calcaneal insertion is specialised and designed to aid the dissipation of stress from the tendon to the calcaneum. The insertion is crescent shaped and has significant medial and lateral projections. The blood supply of the tendon is from the musculotendinous junction, vessels in surrounding connective tissue and the osteotendinous junction. The vascular territories can be classified simply in three, with the midsection supplied by the peroneal artery, and the proximal and distal sections supplied by the posterior tibial artery. This leaves a relatively hypovascular area in the mid-portion of the tendon where most problems occur. The Achilles tendon derives its innervation from the sural nerve with a smaller supply from the tibial nerve. Tenocytes produce type I collagen and form 90% of the cellular component of the normal tendon. Evidence suggests ruptured or pathological tendon produce more type III collagen, which may affect the tensile strength of the tendon. Direct measurements of forces reveal loading in the Achilles tendon as high as 9 KN during running, which is up to 12.5 times body weight.

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Acknowledgments

We thank Dr. Nihal Apaydın from Ankara University Dept. of Anatomy for her rigorous anatomic dissections of Achilles tendon on cadavers and Dr. Uğur Diliçıkık, Dr. Defne Kaya PT, Dr. Ali Öçgüder for their scientific support.

Conflict of interest statement

The authors declare that they have no conflict of interest. No benefits in any form have been received or will be received from any party, commercial or otherwise, related directly or indirectly to the subject of this article.

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Authors and Affiliations

  1. Faculty of Medicine, Department of Orthopedics and Traumatology, Hacettepe University, Ankara, Turkey

    Mahmut Nedim Doral & Ozgür Ahmet Atay

  2. Sports Medicine Department, Hacettepe University, Ankara, Turkey

    Mahmut Nedim Doral & Gürhan Dönmez

  3. Department of Orthopaedic Surgery, Newham University Hospital NHS Trust, London, UK

    Mahbub Alam

  4. Department of Orthopedics and Traumatology, Ankara Etlik İhtisas Training and Research Hospital, Ankara, Turkey

    Murat Bozkurt

  5. Faculty of Medicine, Department of Orthopedics and Traumatology, Karaelmas University, Zonguldak, Turkey

    Egemen Turhan

  6. Barts and The London School of Medicine and Dentistry, Centre for Sports and Exercise Medicine, Queen Mary University of London, Mile End Hospital, 275 Bancroft Road, London, E1 4DG, UK

    Nicola Maffulli

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  1. Mahmut Nedim Doral
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  2. Mahbub Alam
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  3. Murat Bozkurt
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  7. Nicola Maffulli
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Correspondence to Nicola Maffulli.

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Doral, M.N., Alam, M., Bozkurt, M. et al. Functional anatomy of the Achilles tendon. Knee Surg Sports Traumatol Arthrosc 18, 638–643 (2010). https://doi.org/10.1007/s00167-010-1083-7

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  • DOI: https://doi.org/10.1007/s00167-010-1083-7

Keywords

  • Achilles tendon
  • Anatomy
  • Vascular supply
  • Sensory innervation
  • Biomechanics