Flexor Digitorum Longus (FDL)

Authors
Affiliations

Nate Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Figure 1: Muscles of the lower leg
Figure 2: Superficial posterior leg muscles

Deep posterior leg muscles2

Deep posterior leg muscles

The Mucous sheaths of the tendons around the ankle (medial view)2

The Mucous sheaths of the tendons around the ankle (medial view)

1st layer of the plantar foot2

1st layer of the plantar foot

2nd layer of the plantar foot2

2nd layer of the plantar foot

3rd layer of the plantar foot2

3rd layer of the plantar foot
Reading list
  • Ch69 Long toe flexor muscles of the foot
  • Neuman

Origin

Tibia (middle third of posterior surface)

Insertion

Bases of 2-5 distal phalanges

Innervation

Tibial N. (L5, S1, S2)

Action

  • TCJ: PF
  • STJ: INV
  • MTP & IP 2-5: Flexion

MMT

“The FDL and brevis muscles produce IP joint flexion. The motion is tested with the foot in the anatomic position. If the gastrocnemius muscle is shortened, preventing the ankle from assuming the anatomic position, the knee is flexed. The toes may be tested simultaneously. The foot is held in the midposition, and the metatarsals are stabilized. Resistance is applied beneath the distal and proximal phalanges”

Pails & Rails

Read more about [P.A.I.L.’s and R.A.I.L.’s here]

P.A.I.L.’s

  • Plantarflexion
  • Inversion
  • 2-5 MTP/IP Flexion

R.A.I.L.’s

  • Dorsiflexion
  • Eversion
  • 2-5 MTP/IP Extension

Stretch

References

1.
Betts JG, Blaker W. 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.
6.
Dutton M. Dutton’s Orthopaedic Examination, Evaluation, and Intervention. 5th ed. McGraw Hill Education; 2020.

Citation

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