Extensor Indicis

Authors
Affiliations

Nate Yomogida, PT, DPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, PT, DPT

Doctor of Physical Therapy

B.A. in Neuroscience

Figure 1: Muscles that move the Forearm1

Mucous sheaths of the dorsal hand2

Mucous sheaths of the dorsal hand2

Transverse section of distal forearm2

Transverse section of distal forearm2

Transverse cut of the Hand2

Transverse cut of the Hand2
Reading list
  • Extensor digitorum and Extensor indicis Muscles3
  • 4
Muscle Origin Insertion Innervation Action
Extensor indicis Posterior Ulna
IO membrane		 2nd Dorsal digital expansion Radial n.
C7 - C8		 Wrist: Extension
2nd MCP, PIP, DIP: Extension

Origin

  • Ulna (posterior surface)5
  • IO membrane5

Insertion

  • Posterior digital extension of 2nd digit5

Innervation

Posterior Interosseous N. (C7, C8)5

Action

  • Wrist: Extension5
  • 2nd MCP, PIP, DIP: Extension5

Notes

1.
Betts JG, Blaker W. Openstax Anatomy and Physiology. 2nd ed. OpenStax; 2022. https://openstax.org/details/books/anatomy-and-physiology-2e/?Book%20details
2.
Gray H. Anatomy of the Human Body. 20th ed. (Lewis WH, ed.). Lea & Febiger; 1918. https://www.bartleby.com/107/
3.
Donnelly JM, Simons DG, eds. Travell, Simons & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual. Third edition. Wolters Kluwer Health; 2019.
4.
Neumann DA, Kelly ER, Kiefer CL, Martens K, Grosz CM. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 3rd ed. Elsevier; 2017.
5.
Gilroy AM, MacPherson BR, Wikenheiser JC, Voll MM, Wesker K, Schünke M, eds. Atlas of Anatomy. 4th ed. Thieme; 2020.

Citation

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