Download 09-Front_of_Forearm

Dr. Ahmed Fathalla Ibrahim
MUSCLES OF FRONT OF
FOREARM
•
SUPERFICIAL GROUP (5)
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)
1. Flexor pollicis longus (FPL)
2. Flexor digitorum profundus (FDP
3. Pronator quadratus (PQ)
SUPERFICIAL GROUP
•
ORIGINS:
•
All 5 muscles have a HUMERAL HEAD (arising
from the front of medial epicondyle of humerus:
(common flexor origin). IN ADDITION:
3 out of 5 muscles have an ULNAR HEAD:
PT & FDS: arise from medial border of coronoid
process of ulna
FCU: arises from medial surface of olecranon
process & posterior border of shaft of ulna
One muscle has a RADIAL HEAD:
FDS: arises from oblique line & anterior border of
shaft of radius
•
1.
2.
•
•
SUPERFICIAL GROUP
• ACTIONS & INSERTIONS:
• One pronator of radioulnar joints (PT):
produces powerful pronation
• Any muscle acting on radioulnar joint
must be inserted into radius
• Insertion: middle of lateral surface of
shaft of radius (point of maximum
curvature)
SUPERFICIAL GROUP
• ACTIONS & INSERTIONS:
• 3 flexors of wrist joint (FCR, FCU, PL)
• Any “carpi” is inserted into metacarpal bone
• FCR (flexion + abduction of wrist joint):
inserted into 2nd & 3rd metacarpal bones
• FCU (flexion + adduction of wrist joint):
inserted into 5th metacarpal bone (+ pisiform
& hamate)
• PL (flexion of wrist joint): inserted into
palmar aponeurosis
SUPERFICIAL GROUP
• ACTIONS & INSERTIONS:
• One flexor of medial 4 fingers (FDS):
produces flexion of proximal
interphalangeal & metacarpophalangeal
joints of medial 4 fingers
• Insertion: by 4 tendons into the middle
phalanges of medial 4 fingers
SUPERFICIAL GROUP
SUPERFICIAL GROUP
DEEP GROUP
• ALL MUSCLES ARE ATTACHED TO
ANTERIOR SURFACE OF SHAFT
OF RADIUS AND/OR ULNA
DEEP GROUP
Flexor pollicis longus
• ORIGIN: Middle of anterior surface of
shaft of radius (+ interosseous
membrane)
• INSERTION: distal phalanx of thumb
• ACTION: flexion of interphalangeal &
metacarpophalangeal joints of thumb
FLEXOR DIGITORUM
PROFUNDUS
• ORIGIN: Upper ¾ of anterior surface of
shaft 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
shaft of ulna
• INSERTION: Lower ¼ of anterior
surface 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 NERVE EXCEPT:
1. FCU
ULNAR
2. MEDIAL HALF OF FDP
NERVE
FRONT OF FOREARM
FRONT OF FOREARM
MEDIAN NERVE IN FOREARM
•
1.
2.
3.
•
1.
2.
COURSE: The nerve descends
BETWEEN:
The 2 heads of pronator teres
FDS and FDP
Tendons of FDS and FCR
BRANCHES:
Muscular branches to 6 ½ muscles
Cutaneous branch to lateral 2/3 of
palm
ULNAR NERVE IN FOREARM
•
1.
•
1.
2.
3.
COURSE: The nerve descends
BETWEEN:
FCU and FDP
BRANCHES:
Muscular branches to 1 ½ muscles
Cutaneous branch to medial 1/3 of
palm
Cutaneous branch to medial 1/3 of
dorsum and dorsal aspect of medial
1 ½ fingers.