Hey this is Vedika Agrawal and my presentation explains about anatomy of forearm which covers almost every diagram and key point required to understand this topic.
This topic is usually mixed with antaomy of hand and so I separated to keep it easy for you.
reference: BD Chaurasia
1. FOREARM
PREPARED BY – VEDIKA AGRAWAL
(BATCH 2019-20)
ROLL NUMBER – 98
GUIDED AND MOTIVATED BY – Dr. Priya Mehta
MGM ALLIED HEALTH SCIENCE
INSTITUTE
2. INTRODUCTION
Forearm extends between elbow and wrist joints.
Radius and ulna forms its skeleton.
These two bones articulate at both their ends to form superior
and inferior radioulnar joints.
In the upper part radius and ulna articulates with humerus to
form elbow joint.
In lower part radius and ulna articulate with carpel bones to
form wrist joint.
To understand forearm we study it in two sections:
1. Anterior compartment/ Front of forearm
2. Posterior compartment/ Back of forearm
3. FRONT OF FOREARM
SURFACE LANDMARKS
Medial epicondyle of humerus is more prominent than the lateral.
Ulnar nerve can be rolled on posterior surface of medial
epicondyle.
Head of radius can be palpated on posterolateral aspect of
extended elbow, distal to lateral epicondyle.
Styloid process of radius is 1cm below ulna and can be palpated
in the upper part of anatomical snuff box.
Head of ulna forms surface elevation on posteromedial side when
hand is pronated.
Pisiform bone can be felt at base of the hypothenar eminence
and can me palpated when wrist is fully extended.
Tubercle of scaphoid lies beneath lateral part of distal transverse
crease of extended wrist.
4. MUSCLES
It is divided into superficial and deep groups.
superficial group has five muscles
Deep group has three muscles.
There are 2 arteries that and three nerves that accompany the
muscles in the front of forearm.
5. SUPERFICIAL GROUP
MUSCLES ORIGIN INSERSION NERVE
SUPPLY
ACTIONS
Pronator
Teres
Medial epicondyle of
humerus
Middle of lateral aspect
of shaft of radius
Median
nerve
Pronation of
forearm
Flexor Carpi
Radialis
Medial epicondyle of
humerus
Bases of second and
third metacarpal bones
Median
nerve
Flexes and abducts
hand at wrist joint
Palmaris
Longus
Medial epicondyle of
humerus
Flexor retinaculum and
palmar aponeurosis
Median
nerve
Flexes wrist joint
Flexor
digitorum
Superficialis
Medial epicondyle of
humerus; medial
border of coronoid
process of ulna
Anterior oblique line
of shaft of radius
Muscle divides into 4
tendons. Each tendon
divides into 2 slips which
are inserted on sides of
middle phalanx of 2nd to
5th digits
Median
nerve
Flexes middle
phalanx of fingers
and assists in
flexing proximal
phalanx and wrist
joint
Flexor Carpi
Ulnaris
Medial epicondyle of
humerus Medial
aspect of olecranon
process and
posterior border of
ulna
Pisiform bone; insertion
prolonged to hook of
the hamate and base of
fifth metacarpal bone
Median
nerve
Flexes and adducts
the hand at the
wrist ioint
6. DEEP GROUP
MUSCLES ORIGIN INSERSION NERVE
SUPPLY
ACTION
FIexor
digitorum
profundus
• Upper three-fourths of the
anterior and medial surface
of the shaft of ulna .
• Upper three-fourths of the
posterior border of ulna .
• Medial surface of the
olecranon and coronoid
processes of ulna.
• Adjoining part of the
anterior surface of the
interosseous membrane
• The muscle forms 4 tendons
for the medial 4 digits which
enter the palm by passing
deep to the flexor
retinaculum.
• Each tendon is inserted on
the palmar surface of the
base of the distal phalanx.
Median
half by
Ulnar
nerve
Lateral
half by
Anterior
interosse
ous nerve
• Flexor of distal
phalanges
• flexes the other
joints of the
digits, fingers, a
and the wrist.
• chief gripping
muscle
Flexor
pollicis
longus
• Upper three-fourths of the
anterior surface of the shaft
of radius,
• Adjoining part of the
interosseous membrane.
• The tendon enters the palm
by passing deep to the flexor
retinaculum
• It is inserted into the palmar
surface of the distal phalanx
of the thumb
Anterior
interosse
ous nerve
• Flexes the distal
phalanx of the
thumb
Pronator
quadratus
Oblique ridge on the lower one-
fourth of anterior surface of the
shaft of ulna, and the area
medial to it.
• Superficial fibres into the
lower one-fourth of the
anterior surface and the
anterior border of the radius.
• Deep fibres into the
triangular area above the
ulnar notch
Anterior
interosse
ous nerve
• Supeficial fibres
pronate the
forearm
• Deep fibres bind
the lower ends of
radius and ulna
7. RADIAL ARTERY
Radial artery is the smaller terminal branch of the
brachial artery in the cubital fossa.
As compared to the ulnar artery, it is quite superficial
throughout its whole course.
Relations
1. Anteriorly – brachioradialis
2. Posteriorly – biceps brachii, flexor pollicis longus,
flexor digitorum superficialis and pronator
quadratus.
3. Medially – pronator teres, flexor carpi radialis
4. Laterally – brachioradialis, radial nerve
Branches
1. Radial recurrent artery
2. Muscular branches
3. Palmar carpal branch
4. Dorsal carpal branch
5. Superficial palmar branch
8. ULNAR ARTERY
Ulnar artery is the larger terminal branch of the brachial artery, and
begins in the cubital fossa.
The artery runs obliquely downwards and medially in the upper one-
third of the forearm; but in the lower two-thirds of the forearm its
course is vertical.
It enters the palm by passing superficial to the flexor retinaculum.
Relations
1. Anteriorly; muscles arising from common flexor origin and
median nerve.
2. Posteriorly; flexor digitorum profundus.
3. Medially: ulnar nerve, flexor carpi ulnaris.
4. Laterally: flexor digitorum superficialis.
Branches
1. Anterior and posterior ulnar recurrent arteries
2. Common interosseous artery
3. Muscular branches
4. Palmar and dorsal carpal branches
9. MEDIAN NERVE
Course
1. Median nerve lies medial to brachial artery and enters the
cubital fossa.
2. Then it enters the forearm to lie between flexor digitorum
superficialis and flexor digitorum profundus.
3. Then it reaches down the region of wrist where it lies deep and
lateral to palmaris longus tendon.
4. Lastly it passes deep to flexor retinaculum to enter the palm.
Branches
• Muscular branches
• Anterior interosseous branch
• Palmar cutaneous branch
• Articular branches
• Vascular branches
• Communicating branch
10. RADIAL NERVE
Course
• The radial nerve divides into its two terminal
branches in the cubital fossa just below the level of
the lateral epicondyle of the humerus.
Branches
• The deep terminal branch (posterior interosseous)
• The superficial terminal branch
11. ULNAR NERVE
Course
• Ulnar nerve is palpable as it lies behind medial
epicondyle of humerus and is nof a content of cubital
fossa
• It enters the forearm by passing between two heads
of flexor carpi ulnaris, to lie along the lateral border
of flexor carpi ulnaris.
• In the last phase, it courses superficial to the flexor
retinaculum, covered by its superficial slip or volar
carpal ligament to enter the region of palm.
Branches
• Muscular branches
• Palmar cutaneous branch
• Dorsal cutaneous branch
• Articular branches