The
upper limb
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Introduction
The upper limb
▪Is the organ of the body, responsible for
manual activities.
▪It is freely movable, especially its distal
segment - the hand, which is adapted for
grasping and manipulating the objects.
▪The upper limbs are connected to the trunk by a
pectoral girdle.
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Relationship to other regions
Neck
▪The major nerves, arteries and veins of the
upper limb pass between the thorax and the
limb by passing over rib I and through the
axillary inlet.
Back and thoracic wall
▪Muscles that attach the bones of the shoulder
to the trunk are associated with the back and
the thoracic wall.
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Parts of the upper limb
▪For descriptive purposes, the
upper limb is divided into:
The shoulder region
Axilla or armpit,
Scapular region
Pectoral or breast region
The arm
The part between shoulder
and elbow (or cubitus).
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The forearm
The part between the elbow and the wrist.
The hand (or manus)
Consists of:
−Wrist or carpus,
−Hand proper (or metacarpus), and
−Digits (thumb and fingers)
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Parts of the upper limb
Part
Subdivisions
Bones
Joints
▪ Pectoral region
▪Clavicle
Shoulde
▪ Axilla
r region
▪Scapula
▪ Scapular región
▪Sternoclavicular
▪Acromioclavicular
Arm
▪Humerus
▪Shoulder
▪Radius
▪Ulna
▪Elbow
▪Radio-ulnar
▪Carpal
▪Metacarpal
▪Phalanges
▪Wrist/radio-carpal
▪Intercarpal
▪Carpometacarpal
▪Intermetacarpal
▪Metacarpophalangeal
▪Proximal and distal
interphalangeal
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—
Forearm —
Hand
▪Wrist (carpus)
▪Hand proper
(metacarpus)
▪Digits
Comparison between the upper and lower limbs
Homologous parts of the upper and lower limbs
Upper limb
▪Shoulder/pectoral girdle
▪Shoulder joint
Lower limb
▪Hip girdle/pelvic girdle
▪Hip joint
▪Arm
▪Thigh
▪Elbow joint
▪Forearm
▪Knee joint
▪Leg
▪Wrist joint
▪Hand
(A) Carpus
(B) Metacarpus
(C) Fingers
▪Ankle joint
▪Foot
(A) Tarsus
(B) Metatarsus
(C) Toes
Development of the limbs.
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Differences between the upper and lower limbs
Upper limb
Lower limb
Function
▪Prehension (i.e., manipulation of
objects by grasping)
▪Locomotion and transmission of
weight
Bones
▪Smaller and weaker
▪Larger and stronger
Joints
▪Smaller and less stable
▪Larger and more stable
Muscles
▪Smaller and attached to smaller bony
areas.
▪Antigravity muscles less developed
▪Larger and attached to larger bony
areas
▪Antigravity muscles more
developed
Girdle
▪Pectoral girdle
(a) Made up of two bones, clavicle
and scapula
(b) No articulation with vertebral
column
(c) Articulation with axial skeleton is
very small through SC joint
▪Pelvic girdle
(a) Made up of single bone, the hip
bone
(b) Articulates with vertebral column
(c) Articulation with axial skeleton is
large, through sacroiliac joint
Preaxial
border
▪Faces laterally
▪Faces medially
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Bones
of the upper limb
▪Each upper limb consists of 32
bones:
 Scapula, shoulder blade (1)
 Clavicle, collar bone (1)
 Humerus, bone of arm (1)
 Radius and ulna, bones of
forearm (2)
 Carpal bones, bones of wrist
(8)
 Metacarpals, bones of hand (5)
 Phalanges, bones of digits
(fingers) (14)
The Clavicle (collar bone)
▪A long, slender bone that lies horizontally across
the root of the neck just beneath the skin.
▪Is the only long bone without a medullary
cavity.
 Consists of spongy (trabeculae) bone with a
shell of compact bone.
▪It is subcutaneous throughout its extent.
▪The clavicle ossifies in a membrane and it is the
first bone to start ossification at around the 5th
week of development.
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▪It articulates with the sternum and first costal
cartilage medially and with the acromion process
of the scapula laterally.
▪The medial two thirds of the clavicle is convex
anteriorly and its lateral third is concave
anteriorly.
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Parts of clavicle
Sternal end
▪Enlarged and triangular where it articulates
with the manubrium of the sternum at the
sternoclavicular (SC) joint.
Acromial end
▪Is flat where it articulates with the acromion of
the scapula at the acromioclavicular (AC) joint.
▪Nearer to the acromial end on the anterior
border of the clavicle there is a small thickening
called deltoid tubercle.
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The superior surface:
▪Smoother than the inferior surface.
The inferior surface:
▪Rough
Strong ligaments bind it to the 1st rib near its
sternal end and suspend the scapula from its
acromial end.
▪The lateral 1/3 possesses:
▪The conoid tubercle
Gives attachment to the conoid ligament
(medial part of the coracoclavicular lig.).
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▪Trapezoid line
 For attachment of the trapezoid ligament
(the lateral part of coracoclavicular
ligament).
▪In the meddle third of the shaft of the clavicle :
▪The subclavian groove
Site of attachment of the subclavius muscle.
▪More medially is the impression for the
costoclavicular ligament, that gives attachment
to the ligament binding the 1st rib to the clavicle,
limiting elevation of the shoulder.
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Right clavicle showing attachments of the muscles and ligaments:
A, superior surface; B, inferior surface.
▪Forces of the upper limb are
transmitted to the axial skeleton by
clavicle through costoclavicular
ligament and sternoclavicular joint.
Transmission of force in the upper limb.
Clinical correlations
▪The fracture at the
junction of lateral one-third
and medial two-third occurs
because:
This is the weakest site.
Two curvatures of clavicle
meet at this site.
The transmission of forces
(due to impact) from the
clavicle to scapula occur
at this site through
coracoclavicular ligament.
Clavicle fracture:
A, medial fragment;
B, lateral fragment.
The Scapula
▪Is a large triangular bone in the dorso-lateral
aspect of the thorax at the level of the 2nd - 7th
ribs.
▪Articulates with the humerus and the clavicle.
▪The scapula has body and three processes:
▪The body is triangular, thin, and transparent.
▪It presents:
Two surfaces: costal and dorsal.
Three borders: superior, lateral, and medial.
Three angles: inferior, superior, and lateral.
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B. Posterior aspect
▪The dorsal surface presents a shelf-like projection
on its upper part called spinous process.
▪The superolateral angle of the scapula forms the
glenoid cavity, or fossa.
Glenoid cavity is enlarged by a glenoidal
labrum (fibrocartilaginous rim) to
accommodate the large head of the humerus.
✓Above and below the glenoid cavity there are
supraglenoid and infraglenoid tubercles that
provide attachment sites for the long heads of
biceps and triceps muscles respectively.
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Scapula
Lateral view
The lateral angle is thickened and called
head of the scapula, which is connected
to the plate-like body by an
inconspicuous neck.
▪There are three processes
✓Coracoid process: projects above the glenoid
cavity and provides attachment for muscles and
ligaments.
Medial to the base of the coracoid process is
the suprascapular (scapular) notch.
▪Bridged over by the suprascapular (superior
transverse scapular) ligament forming a foramen that
transmits the suprascapular nerve to the supraspinous
fossa, while the suprascapular vessels ride over the
ligament.
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✓Spinous process: is a shelf-like bony projection
on the dorsal aspect of the body.
✓Acromion process: projects forwards almost at
right angle from the lateral end of the spine.
▪The dorsal surface of the scapula is divided by
the spine into the supraspinous fossa above and
an infraspinous fossa below.
The two fossae communicate laterally via
the spinoglenoidal notch.
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▪The anterior surface (costal surface) of the
scapula:
Is concave and forms the shallow subscapular
fossa.
 Together with its related muscle (subscapularis),
move freely over the underlying thoracic wall.
▪The lateral border of the scapula is strong and
thick for muscle attachment, whereas the medial
border and much of the superior border is thin
and sharp.
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A. Anterior aspect
The humerus
Upper end (proximal end)
Head
 Directed medially, backwards and upwards
 Articulates with the glenoid cavity to form
shoulder joint.
 Covered by a hyaline cartilage.
Neck
Anatomical:
▪Formed by the groove circumscribing the head
and separating it from the greater and lesser
tubercles.
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It indicates the line of attachment of the
glenohumeral joint capsule.
Surgical neck:
▪A short constriction in the upper end of the
shaft below the greater and lesser tubercles/
below the epiphyseal line.
 It is related to axillary nerve and posterior
and anterior circumflex humeral vessels.
Lesser tubercle:
▪Is an elevation on the anterior aspect of the
upper end just above the surgical neck.
Provides attachment to subscapularis muscle.
Right humerus: A, anterior view; B, posterior view.
Greater tubercle:
▪An elevation that forms the
lateral part of the upper
end.
▪Its superior surface and
posterior surface are marked
by three large smooth facets
for muscle tendon
attachment: (supraspinatus,
infraspinatus, and teres
minor muscles, respectively)
SIT
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Right humerus showing attachments of the muscles and ligaments:
A, anterior aspect; B, posterior aspect.
Intertubercular sulcus (Bicipital groove)
 It is a vertical groove between lesser and
greater tubercles.
 Contains long head of biceps, enclosed in the
synovial sheath and ascending branch of
anterior circumflex humeral artery.
 Roughenings on the lateral and medial lips
and on the floor of the intertubercular sulcus
mark sites for the attachment of the pectoralis
major, teres major, and latissimus dorsi
muscles, respectively.
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Shaft
▪Is rounded in the upper half and triangular in
the lower half.
▪Has three borders and three surfaces:
 Borders: Anterior, Lateral, and Medial.
 Surfaces: Anterolateral, Anteromedial, and
Posterior.
▪The posterior surface of the humerus is marked
on its superior aspect by a linear roughening for
the attachment of the lateral head of the triceps
brachii muscle.
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▪Has
Deltoid tuberosity: laterally, for attachment
of the deltoid muscle.
Behind and below the tuberosity is radial
sulcus (radial groove, radial fossa or spiral
groove through which the radial nerve pass.
▪Approximately in the middle of the shaft, the
medial border is marked by thin elongate
roughening for the attachment of the
coracobrachialis muscle.
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▪Intermuscular septa, which
separate the anterior
compartment from the
posterior compartment,
attach to the medial and
lateral borders of the shaft
of the humerus.
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▪Distally, the bone becomes flattened, and these
borders expand as the lateral supraepicondylar
ridge (lateral supracondylar ridge) and the
medial supraepicondylar ridge (medial
supracondylar ridge).
 The lateral supraepicondylar ridge is more
pronounced than the medial and is
roughened for the attachment of muscles
found in the posterior compartment of the
forearm.
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Lower End
▪Has condyles, epicondyles, and fossae:
The Condyle
▪Has two articular parts, the capitulum and the
trochlea, articulate with the two bones of the
forearm.
The capitulum
▪Articulates with the radius of the forearm.
▪Not visible when the humerus is viewed from
the posterior aspect.
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The trochlea
▪Medial to the capitulum.
▪Articulates with the ulna of
the forearm.
▪Its medial edge is more
pronounced than its lateral
edge and, unlike the
capitulum, it extends onto
the posterior surface of the
bone.
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The two epicondyles
The medial epicondyle
 A large bony protuberance, projects medially
from the distal end of the humerus.
 On its surface, it bears a large oval impression
for the attachment of muscles in the anterior
compartment of the forearm.
 The ulnar nerve passes from the arm into the
forearm around the posterior surface of the
medial epicondyle.
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The lateral epicondyle
Is much less pronounced
than the medial
epicondyle.
It is lateral to the
capitulum and has a large
irregular impression for
the attachment of muscles
in the posterior
compartment of the
forearm.
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The three fossae
▪Accommodate projections from the bones in the
forearm during movements of the elbow joint.
▪The radial fossa:
 Immediately superior to the capitulum on
the anterior surface of the humerus.
 Accommodates the edge of the head of the
radius when the forearm is fully flexed.
▪The coronoid fossa:
 Adjacent to the radial fossa and is superior
to the trochlea.
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 Receives the coronoid process of the ulna
during full flexion of the elbow
▪The olecranon fossa:
▪Immediately superior to the trochlea on the
posterior surface of the distal end of the
humerus.
▪Accommodates the olecranon process of the
ulna during full extension of the elbow.
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Clinical correlates
The three nerves related to the
back of the humerus.
These nerves are involved in the
fracture of the humerus at these
sites.
▪Common sites of fractures of the humerus:
Surgical neck.
Shaft.
Supracondylar region.
The Forearm
The Radius
▪Lateral bone of the forearm & is homologous
with the tibia of lower limb.
▪Thinner proximally & progressively thickens
distally.
▪Consists of three parts: upper end, shaft, and
lower end.
Proximal end
•Consists of the head, neck & radial tuberosity.
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Right radius and ulna:
A, Anterior view;
B, Posterior view
The Head
 Disc shaped & is covered with hyaline
cartilage.
 Has superior concave surface which articulates
with capitulum of humerus at the elbow joint.
 Has articular circumference that rotates in the
radial notch of the ulna, covered by hyaline
cartilage & surrounded by annular ligament.
The Neck
 Is a short and narrow cylinder of bone
between the expanded head and the radial
tuberosity on the shaft.
The radial tuberosity
 A large blunt projection on the medial surface
of the radius immediately inferior to the neck.
 Much of its surface is roughened for the
attachment of the biceps brachii tendon.
 The oblique line of the radius continues
diagonally across the shaft of the bone from
the inferior margin of the radial tuberosity.
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The shaft
▪Is triangular in cross-section,
with:
Three borders (anterior,
posterior, and
interosseous).
Three surfaces (anterior,
posterior, and lateral).
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The anterior border
▪Begins as a continuation of the radial
tuberosity.
▪In the superior third of the bone, it crosses the
shaft diagonally, from medial to lateral, as the
oblique line of the radius.
The posterior border
▪Is distinct only in the middle third of the bone.
The interosseous border
▪Is sharp and is the attachment site for the
interosseous membrane, which links the radius
to the ulna.
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The posterior surface
▪Is characterized by the presence of a large dorsal
tubercle, which acts as a pulley for the tendon of
one of the extensor muscles of the thumb
(extensor pollicis longus).
The medial surface
▪Is marked by a prominent facet for articulation
with the distal end of the ulna.
The lateral surface
▪Is diamond shaped and extends distally as a
styloid process.
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▪The distal end of the bone is marked by two
facets for articulation with two carpal bones (the
scaphoid and lunate).
The Ulna
▪Is the medial and longer bone of the forearm
and is homologous to fibula of lower limb.
▪Its thickness decreases in a distal direction.
Proximal/Upper End.
▪Presents the olecranon, coronoid process, the
trochlear and radial notches and the tuberosity
of ulna.
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The olecranon
 A large projection of bone that extends
proximally from the ulna.
 Its anterolateral part contributes to the
formation of the trochlear notch, which
articulates with the trochlea of the humerus.
 The superior surface is marked by a large
roughened impression for the attachment of
the triceps brachii muscle.
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Is the attachment site for the
brachialis muscle.
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The coronoid process
 Projects anteriorly from the proximal end of
the ulna.
 Its superolateral surface is articular and
participates, with the olecranon, in forming
the trochlear notch.
 The lateral surface is marked by the radial
notch for articulation with the head of the
radius.
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The shaft of the ulna
Tapers from above down.
It has a sharp interosseous border laterally for
the attachment of the interosseous membrane.
The posterior border is rounded and
subcutaneous and can be easily palpated
throughout its length.
Below the radial notch is the supinator crest
that gives origin to the supinator muscle.
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The distal end
▪It presents a convex articular surface on its
lateral side for articulation with the ulnar notch
of radius to form the inferior radio-ulnar joint.
▪ Its inferior surface is smooth and separated
from wrist joint by an articular disc of inferior
radio-ulnar joint.
▪Has projecting from its medial aspect the styloid
process.
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Bones of the Hand
▪Three groups of bones in the hand:
 The eight carpal bones are the bones of the
wrist.
 The five metacarpals (I to V) are the bones
of the metacarpus.
 The phalanges are the bones of the digits-the
thumb has only two, the rest of the digits
have three.
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Carpal Bones (G. Corpus = wrist)
▪Arranged in two rows.
1. Proximal row contains (from lateral to medial)
 Scaphoid
 Lunate
 Triquetral
 Pisiform
2. Distal row contains in the same order
 Trapezium
 Trapezoid
 Capitate
 Hamate
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Carpal bone Identifying features
▪Boat-shaped
1. Scaphoid ▪Has constriction (neck)
▪Has tubercle on distal part of its palmar surface
2. Lunate
▪Moon-shaped/crescentic
▪Pyramidal in shape
3.Triquetral ▪Oval facet on the distal part of its palmar surface for
articulation with pisiform
▪Pea-shaped/pea-like
4. Pisiform
▪Oval facet on the proximal part of its dorsal surface
▪Quadrilateral in shape
5.Trapezium
▪Has groove and crest (tubercle) on its palmar surface
6. Trapezoid ▪Shoe-shaped
▪Largest carpal bone
7. Capitate
▪Has rounded head on its proximal surface
▪Wedge-shaped
8. Hamate
▪Hook-like process projects from distal part of its palmar
surface
▪The carpal bones do not lie in a flat coronal
plane; rather, they form an arch, whose base is
directed anteriorly.
 The lateral side of this base is formed by the
tubercles of the scaphoid and trapezium.
 The medial side is formed by the pisiform
and the hook of hamate.
▪The flexor retinaculum attaches to, and spans the
distance between, the medial and lateral sides of
the base to form the anterior wall of the so-called
carpal tunnel.
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Palmar aspect of the carpal and metacarpal bones of the left hand
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Dorsal aspect of the carpal and metacarpal bones of the
left hand.
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The sides and roof of the carpal tunnel are
formed by the arch of the carpal bones.
Metacarpals
▪These are 5 miniature long bones, which are
numbered from lateral to medial side.
 Metacarpal I is related to the thumb.
 Metacarpals II to V are related to the index,
middle, ring, and little fingers, respectively.
 Each bone has a head (placed distally), a shaft
and a base (at the proximal end).
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Phalanges
▪There are 14 phalanges in each hand, 3 for each
finger and 2 for the thumb.
▪Each phalanx has a base, a shaft and a head.
▪The base of each proximal phalanx articulates
with the head of the related metacarpal bone.
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