Anterior Forearm (Second and Third Layers) AOIs

Flexor Digitorum Superficialis: Origin

• Humero-ulnar head: medial epicondyle, cornoid process of ulna

• Radial head: oblique line of radius

Flexor Digitorum Superficialis: Insertion

• passes through carpal tunnel

• sides of middle phalanx of medial four fingers

Flexor Digitorum Superficialis: Innervation

• median nerve (C7, C8, T1)

Flexor Digitorum Superficialis: Action

• flexes wrist

• flexes MCP

• flexes PIP

Flexor Pollicis Longus: Origin

• mid half of anterior radial shaft and adjacent interosseous membrane

Flexor Pollicis Longus: Insertion

• passes through carpal tunnel

• base of distal phalanx of thumb

Flexor Pollicis Longus: Innervation

• anterior interosseous nerve (from median nerve) C8, T1

Flexor Pollicis Longus: Action

• flexes wrist

• flexes 1st MCP

• flexes 1st PIP

Flexor Digitorum Profundus: Origin

• proximal ¾ of medial and anterior ulna and adjacent interosseous membrane

Flexor Digitorum Profundus: Insertion

• passes through carpal tunnel

• bases of distal phalanges of 2nd, 3rd, 4th, 5th digits

Flexor Digitorum Profundus: Innervation

• digits 2 and 3: median nerve, anterior interosseous branch (C8, T1)

• digits 4 and 5: ulnar nerve (C8, T1)

Flexor Digitorum Profundus: Action

• flexes wrist

• flexes DIP of 2nd, 2rd, 4th, and 5th digits

Pronator Quadratus: Origin

• distal 1/4 , anterior surface of ulna

Pronator Quadratus: Insertion

• distal 1/4, anterior surface of radius

Pronator Quadratus: Innervation

• anterior interosseous nerve from median nerve (C8, T1)

Pronator Quadratus: Action

• pronates forearm