Also called: FDS
The flexor digitorum superficialis is the middle-layer flexor of the fingers. It arises from the medial epicondyle, ulna and radius and splits into four tendons that insert on the middle phalanges of digits two to five. The median nerve supplies it, and it flexes the proximal interphalangeal joints.
| Origin | Humeroulnar head: medial epicondyle and coronoid process. Radial head: anterior oblique line of the radius. |
|---|---|
| Insertion | Sides of the shafts of the middle phalanges of the four fingers. |
| Innervation | Median nerve (C7-T1). |
| Blood supply | Ulnar artery and radial artery. |
| Action | Flexes the proximal interphalangeal joints; assists flexion at the metacarpophalangeal joints and the wrist. |
3D model: BodyParts3D (CC BY 4.0), adult male reference anatomy. Highlighted structure shown with nearby bones for context.
Its tendons split around the tendons of flexor digitorum profundus, which pass through them to reach the distal phalanges.
On the middle phalanges of the index, middle, ring and little fingers.
The superficialis flexes the middle phalanx, whereas the profundus continues to flex the distal phalanx.
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