Dr. Ahmed Fathalla Ibrahim

MUSCLES OF FRONT OF FOREARM

• SUPERFICIAL GROUP (5)SUPERFICIAL GROUP (5)From lateral to medial:From lateral to medial:1. Pronator teres (PT)2. Flexor carpi radialis (FCR)3. Palmaris longus (PL) (may be absent)4. Flexor digitorum superficialis FDS)5. Flexor carpi ulnaris (FCU)• DEEP GROUP (3)DEEP GROUP (3)1. Flexor pollicis longus (FPL)2. Flexor digitorum profundus (FDP3. Pronator quadratus (PQ)

SUPERFICIAL GROUP

• ORIGINS:ORIGINS:• All 5 muscles have a HUMERAL HEAD (arising

from the front of medial epicondyle of humerus: (common flexor origincommon flexor origin). IN ADDITION:

• 3 out of 5 muscles have an ULNAR HEADULNAR HEAD:1. PT & FDS: arise from medial border of coronoid

process of ulna2. FCU: arises from medial surface of olecranon

process & posterior border of shaft of ulna• One muscle has a RADIAL HEADRADIAL HEAD:• FDS: arises from oblique line & anterior border of

shaft of radius

SUPERFICIAL GROUP

• ACTIONS & INSERTIONS:ACTIONS & INSERTIONS:

• One pronator of radioulnar joints (PT): produces powerful pronation

• Any muscle acting on radioulnar joint Any muscle acting on radioulnar joint must be inserted into radiusmust be inserted into radius

• Insertion:Insertion: middle of lateral surface of shaft of radiusradius (point of maximum curvature)

SUPERFICIAL GROUP

• ACTIONS & INSERTIONS:ACTIONS & INSERTIONS:• 3 flexors of wrist joint (FCR, FCU, PL)• Any “carpi” is inserted into metacarpal bone• FCR (flexion + abduction of wrist joint):

insertedinserted into 22ndnd & 3 & 3rdrd metacarpal bones metacarpal bones• FCU (flexion + adduction of wrist joint):

insertedinserted into 55thth metacarpal bone metacarpal bone (+ pisiform & hamate)

• PL (flexion of wrist joint): insertedinserted into palmar aponeurosis

SUPERFICIAL GROUP

• ACTIONS & INSERTIONS:ACTIONS & INSERTIONS:• One flexor of medial 4 fingers (FDS):

produces flexion of proximal interphalangeal & metacarpophalangeal joints of medial 4 fingers

• Insertion:Insertion: by 4 tendons4 tendons into the middlemiddle phalanges of medial 4 fingersmedial 4 fingers

SUPERFICIAL GROUP

SUPERFICIAL GROUP

DEEP GROUP

• ALL MUSCLES ARE ATTACHED ALL MUSCLES ARE ATTACHED TO TO ANTERIOR SURFACE OF ANTERIOR SURFACE OF SHAFT OF RADIUS AND/OR ULNASHAFT OF RADIUS AND/OR ULNA

DEEP GROUP

Flexor pollicis longus

• ORIGIN: Middle of anterior surface of anterior surface of shaft of radiusshaft of radius (+ interosseous membrane)

• INSERTION: distal phalanx of thumb

• ACTION: flexion of interphalangeal & metacarpophalangeal joints of thumbthumb

FLEXOR DIGITORUM PROFUNDUS

• ORIGIN: Upper ¾ of anterior surface of anterior surface of shaft of ulnashaft of ulna (+ interosseous membrane)

• INSERTION: by 4 tendons into the distal phalanges of medial 4 fingers

• ACTION: flexion of distal & proximal interphalangeal + metacarpophalangeal joints of medial 4 fingers

PRONATOR QUADRATUS

• ORIGIN: Lower ¼ of anterior surface of anterior surface of shaft of ulna shaft of ulna

• INSERTION: Lower ¼ of anterior anterior surface of shaft of radiussurface of shaft of radius

• ACTION: main pronator of radioulnar joints

DEEP GROUP

DEEP GROUP

NERVE SUPPLY

• ALL MUSCLES OF FRONT OF FOREARM ARE SUPPLIED BY MEDIAN NERVEMEDIAN NERVE EXCEPT:

1. FCU ULNAR

2. MEDIAL HALF OF FDP NERVE