Flexor Digitorum Superficialis Muscle Anatomy

Overview
Origin Humeroulnar head: Medial epicondyle of humerus and coronoid process of ulna
Radial head: Proximal half of anterior border of radius
Insertion Bases of middle phalanges of digits two to five
Action Flexion of fingers at proximal interphalangeal joints and at metacarpophalangeal joints
Can also provide assistance during flexion of wrist
Nerve Median nerve (C7, C8, T1)
Artery Ulnar artery

Location & Overview

The flexor digitorum superficialis is a muscle of the forearm and is often considered to be a superficial muscle. The flexor digitorum superficialis also crosses the elbow joint via the common flexor tendon. The flexor digitorum profundus passed deep to the digitorum superficialis. Distally, at the wrist, the flexor digitorum superficialis splits into four tendons. These four tendons pass deep to the flexor retinaculum through the carpal tunnel. Once the flexor digitorum superficialis reaches the distal part of the proximal phalanx of the finger, it then has an opening/split in the muscle tendon, where the tendon of the flexor digitorum profundus is able to pass through [1]Okafor L, Varacallo M. Anatomy, Shoulder and Upper Limb, Hand Flexor Digitorum Superficialis Muscle. [Updated 2021 Oct 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; … Continue reading [2]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

Origin & Insertion

There are two points of origin for the flexor digitorum superficialis muscle. The first is the humeroulnar head of the muscle, which originates from the medial epicondyle of the humerus and the coronoid process of the ulna. The second is the radial head, originating from the proximal half of the anterior border of the radius. The flexor digitorum superficialis then continues distally, where it crosses the wrist joint and reaches the fingers. It the inserts onto the bases of the middle phalanges of digits two to five [3]Okafor L, Varacallo M. Anatomy, Shoulder and Upper Limb, Hand Flexor Digitorum Superficialis Muscle. [Updated 2021 Oct 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; … Continue reading [4]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

Actions

The flexor digitorum superficialis flexes the proximal interphalangeal joints and metacarpophalangeal joints of digits 2-5. It is also able to provide assistance during flexion of the wrist. The primary flexors of the wrist are the flexor carpi radialis and the flexor carpi ulnaris. The flexor digitorum superficialis is able to flex each of the fingers it connects to independently [5]Okafor L, Varacallo M. Anatomy, Shoulder and Upper Limb, Hand Flexor Digitorum Superficialis Muscle. [Updated 2021 Oct 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; … Continue reading [6]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

Innervation

The median nerve and ulnar artery pass between the humeroulnar and radial heads of the flexor digitorum superficialis muscle. The flexor digitorum superficialis muscle is innervated by the median nerve (C7, C8, T1) [7]Okafor L, Varacallo M. Anatomy, Shoulder and Upper Limb, Hand Flexor Digitorum Superficialis Muscle. [Updated 2021 Oct 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; … Continue reading [8]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

Blood Supply

Blood is supplied to the flexor digitorum superficialis muscle primarily from the ulnar artery [9]Okafor L, Varacallo M. Anatomy, Shoulder and Upper Limb, Hand Flexor Digitorum Superficialis Muscle. [Updated 2021 Oct 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; … Continue reading.

Images

flexor digitorum superficialis superficial view

Highlighted in green, we can the flexor digitorum superficialis from a superficial view.

flexor digitorum superficialis muscle

Here we can see the flexor digitorum superficialis muscle by itself.

flexor digitorum superficialis muscle

Here we can see a labelled diagram of the bones and the joints of the phalanges of the hand.

origins of the flexor digitorum superficialis muscle highlighted in red

Here we can see the origin points of the flexor digitorum superficialis muscle highlighted in red. The humeroulnar head originates on the medial epicondyle of humerus and coronoid process of the ulna. The radial head originates on the proximal half of the anterior border of the radius.

insertions of the flexor digitorum superficialis muscle highlighted in blue

Here we can see the insertion points of the flexor digitorum superficialis muscle highlighted in blue. The insertions are on the bases of the middle phalanges of digits two to five.

Want some flashcards to help you remember this information? Then click the link below:
Flexor Digitorum Superficialis Flashcards

References

References
1, 3, 5, 7, 9 Okafor L, Varacallo M. Anatomy, Shoulder and Upper Limb, Hand Flexor Digitorum Superficialis Muscle. [Updated 2021 Oct 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK539723/
2, 4, 6, 8 Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017