Related Experiment Video
Updated: Feb 16, 2026

Author Spotlight: Isolation of Long Muscle Fibers from Mouse Hindlimb Muscles for Studying Excitation-Contraction Coupling Across Fiber Types
Published on: December 1, 2023
Flexor Pollicis Brevis Muscle. Anatomical Study and Clinical Implications
Edie Benedito Caetano1, Yuri da Cunha Nakamichi1, Renato Alves de Andrade1
1Department of Orthopedics of the Pontifical Catholic University of São Paulo, Paulo, Brazil.
Introduction:
This paper reports anatomical study of nature, incidence, innervation and clinical implications of Flexor Pollicis Brevis muscle (FPB).
Material And Methods:
The anatomical dissection of 60 limbs from 30 cadavers were performed in the Department of Anatomy of Medical School of Catholic University of São Paulo.
Results:
The superficial head of FPB has been innervated by the median nerve in 70% and in 30% it had double innervation. The deep head of FPB were absent in 14%, in 65%, occurred a double innervation. In 17.5% by deep branch of ulnar nerve and in 3.6% by recurrent branch of median nerve.
Conclusion:
The pattern of innervation more frequent in relationship to the flexor pollicis brevis muscle and should be considered as a normal pattern is that superficial head receives innervation of branches of median nerve and the deep head receives innervation of ulnar and median nerve.
Related Concept Videos
Anatomical Positions
The body is upright, facing forward, and standing erect.
The feet are parallel and flat on the floor.
The arms are hanging by the...
Aneurysm II: Clinical Manifestations and Diagnostic Studies
Anatomical Terminology
Anatomical Movements
Here are some common anatomical movements:
Flexion and extension motions are in the sagittal (anterior–posterior) plane of motion. These movements take place at the shoulder, hip, elbow, knee, wrist,...
Hypertension III: Clinical Manifestations and Diagnostic Studies
Venous Thrombosis II: Clinical Manifestations and Diagnostic Studies

