Flexor Pollicis Brevis (FPB)

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: Intrinsic Muscles of the Hand¹

Palmar muscles of the hand (left)²

Reading list

• MMT³

Muscle	Origin	Insertion	Innervation	Action
Flexor pollicis brevis	Flexor retinaculum Capitate Trapezium	1st proximal phalanx via radial sesamoid	Median n. Ulnar n. C8 - T1	CMC: Flexion

Origin

• Superficial head: Flexor retinaculum⁴
• Deep head: Capitate, Trapezium⁴

Insertion

Lateral side of base of 1st proximal phalan (via the radial sesamoid)⁴

Innervation

• Superficial head: Recurrent Br. of Median N.⁴
• Deep head: Deep Br. of Ulnar N.⁴
• (C8, T1)⁴

Action

1st CMC: Flexion⁴

Notes

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.

Weinstock D. NeuroKinetic Therapy: An Innovative Approach to Manual Muscle Testing. North Atlantic Books; 2010.

4.

Gilroy AM, MacPherson BR, Wikenheiser JC, Voll MM, Wesker K, Schünke M, eds. Atlas of Anatomy. 4th ed. Thieme; 2020.