Foot Lumbrical Muscles

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: Intrinsic foot muscles¹

1st layer of the plantar foot²

2nd layer of the plantar foot²

3rd layer of the plantar foot²

Reading list

• Ch70 Intrinsic muscles of the foot³
• Neuman⁴

Overview

Muscle	Origin	Insertion	Innervation	Action
Lumbricals (Foot)	FDL tendons (medial borders)	2-5th toes at dorsal aponeurosis	Medial Plantar n. Lateral Plantar n. S2 - S3	2nd-5th Toes: MTP Flexion, PIP Extension, DIP Extension

Origin

Medial borders of tendons of FDL⁵

Insertion

Dorsal aponeurosis of toes 2-5⁵

Innervation

• 1st lumbrical (2nd toe): Medial Plantar N. (S2, S3)⁵
• 2-4 Lumbricals (3rd-5th toes): Lateral Plantar N. (S2, S3)⁵

Action

• MTP 2-5: Flexion⁵
• IP 2-5: Extension⁵
• Toes 2-5: Adducts toes 2-5 towards big toe⁵

MMT

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.