Muscles - Upper Limb
MSK 01 - Pectoral Region & Back
1. Anterior Thoracoappendicular Muscles
Muscle
Proximal Attachment
(Origin)
Distal Attachment
(Insertion)
Action
Nerves
Pectoralis Major
- Clavicular head
- Sternocostal head
Bicipital groove of
Humeras
- Adduction of arm
- Medial rotation arm
- Clavicular head
helps flex extended
arm
- Sternocostal helps
extend flexed arm
- Medial pectoral
nerves
- Lateral pectoral
nerves
Pectoralis Minor
3rd – 5th ribs close to
CC
Coracoid process of
scapula
- Depresses shoulder
- Stabilises scapula
by withdrawing it
against thoracic wall
Medial pectoral
nerve (C8, T1)
Subclavius
1st rib at junction with
1st CC
Subclavian groove
Fixes clavicle during
movement of
shoulder
Nerve to
subclavius
(upper trunk of
brachial plexus)
Serratus Anterior
Lateral parts of upper
8-9 of upper ribs
Anterior aspect of
medial border and
inferior angle of
scapula
- Draws scapula
Long thoracic
forward (protrusion in nerve
boxing)
- Fixes scapula
against thoracic wall
- Rotates scapula
outwards in abduction
the arm above 90o
2. Posterior Thoracoappendicular Muscles
Muscle
Proximal Attachment
(Origin)
Distal Attachment
(Insertion)
Action
- Medial 3rd of superior
nuchal line
- External occipital
protuberance
- Spinous processes
C1 – T12
- Upper fibres:
lateral 1/3rd of
clavicle
- Middle fibres:
upper border of
spine of scapula,
acromion
- Lower fibres:
medial end of spine
of scapula
Elevating, Depressing,
Rotating, Retracting
Latissimus Dorsi
(Superficial)
- Vertebral spines of
T7 – T12
- Inferior 3-4 ribs
- Thoracolumbar fascia
- Iliac crest
Has broad
aponeurosis which
inserts on floor of
bicipital groove of
humerus
- Extension, adduction
and medial rotation of
arm
- Elevates trunk when
climbing along with
pectoralis major
- “climbing muscle”
-“swimmer’s muscle”:
backstroke swimming
Thoracodorsal
nerve (C6 - C8)
Levator Scapulae
(Deep)
Transverse processes
of C1 – C4
Medial border of
scapula (superior to
root of scapular
spine)
Elevates the scapula
- Dorsal scapular
nerve
- Cervical nerves
C3 – C4
Rhomboideus Major
(Deep)
Spines of vertebrae T2
– T5
Medial border of
scapula (inferior to
root of spine)
Retracts and fixes
scapula to thoracic
wall
Dorsal scapular
nerve
Rhomboideus Minor
(Deep)
Inferior end of
ligamentum nuchae
(C7) and T1
Medial end of spine
of scapula
Retracts and fixes
scapula to thoracic
wall
Dorsal scapular
nerve
Trapezius
(Superficial)
Nerves
Motor –
accessory nerve
(CN XI)
Sensory – ventral
rami of C3, C4
(proprioception)
3. Scapulohumeral Muscles
Muscle
Proximal Attachment
(Origin)
Distal Attachment
(Insertion)
Action
Nerves
Deltoid
(Responsible for
rounded contour of
shoulder)
- Anterior fibres: lateral Deltoid tuberosity of
3rd of clavicle
humerus
- Middle fibres:
multipennate fibres
from acromion of
scapula
- Posterior fibres: lower
margin of spine of
scapula
- Anterior F: flexion
and medial
rotation of arm
- Middle F:
abduction of arm
- Posterior F:
extension and
lateral rotation of
arm
Axillary Nerve
Teres Major
Posterior surface of
inferior angle of
scapula
Bicipital groove of
humerus
Adduction and
medial rotation of
arm
Lower
subscapular
nerve
Teres Minor (RC)
Superior 2/3rd of
lateral border of
scapula
- Greater tuberosity
of humerus
- Capsule shoulder
jt
Lateral rotation of
arm
Axillary nerve
Supraspinatus (RC)
Supraspinous fossa of
scapula
- Greater tuberosity
of humerus
- Capsule shoulder
jt
Rotation of arm
Suprascapular
nerve
Infraspinatus (RC)
Infraspinous fossa of
scapula
- Greater tuberosity
of humerus
- Capsule shoulder
jt
Lateral rotation of
arm
Suprascapular
nerve
Subscapularis (RC)
Subscapular fossa of
scapula
Lesser tuberosity of
humerus
Medially rotates
arm
Upper and
lower
subscapular
nerve
MSK 03 - Arm & Cubital Fossa
1. Rotator Cuff Muscles
Muscle
Proximal Attachment
(Origin)
Distal Attachment
(Insertion)
Action
(Humerus)
Nerves
Supraspinatus
Supraspinous fossa
Superior facet of
greater tubercle
Abduction
Suprascapular
nerve
Infraspinatus
Infraspinous fossa
Middle facet of
greater tubercle
External rotation
Suprascapular
nerve
Teres Minor
Middle half of lateral
border
Inferior facet of
greater tubercle
External rotation
Axillary nerve
Subscapularis
Subscapular fossa
Lesser tubercle
Inferior facet of
greater tubercle
Upper and lower
subscapular nerve
2. Anterior Compartment of The Arm
Muscle
Proximal Attachment
(Origin)
Distal Attachment
(Insertion)
Action
(Humerus)
Nerves
Biceps Brachii
(Short head)
Tip of coracoid process Tuberosity of radius
of scapula
and fascia of
forearm via bicipital
aponeurosis
- Flexes forearm
- Supinates
forearm
- Resists
dislocation of the
shoulder
Musculocutaneous
nerve
Biceps Brachii
(Long head)
Supraglenoid tubercle
of scapula
Tuberosity of radius
and fascia of
forearm via bicipital
aponeurosis
- Helps flex and
adduct the arm
- Resists
dislocation of the
shoulder
Musculocutaneous
nerve
Brachialis
(Main flexor of the
forearm, workhorse
of the elbow flexors)
Distal hald of anterior
surface of humerus
Coronoid process
of ulna
Flexes forearm in
all positions
Musculocutaneous
& Radial nerve
Coracobrachialis
Tip of coracoid proces
of scapula
Middle third of
medial surface of
humerus
- Helps flex and
adduct the arm
- Resists
dislocation of
shoulder
Musculocutaneous
nerce
3. Posterior Compartment of The Arm
Muscle
Proximal Attachment
(Origin)
Distal Attachment
(Insertion)
Action
(Humerus)
Nerves
Triceps Brachii
(Long head)
Infraglenoid tubercle
(3 heads converge
into one tendon) →
olecranon of the
ulna
Extension of elbow
joint
Radial nerve
(axillary nerve in
some individuals)
Triceps Brachii
(Lateral head)
Humerus (Superior to
the radial groove)
(3 heads converge
into one tendon) →
olecranon of the
ulna
Extension of elbow
joint
Radial nerve
Triceps Brachii
(Medial head - deep
to the other two)
Humerus (inferior to
the radial groove)
(3 heads converge
into one tendon) →
olecranon of the
ulna
Extension of elbow
joint
Radial nerve
Anconeus
Lateral epicondyle of
humerus
Lateral surface of
olecranon and
superior part of
posterior surface of
ulna
- Assists in elbow
extension
- Stabilises the
elbow joint
Radial nerve
MSK 04 - Forearm
1. Anterior Compartment (Flexor-Pronator) of The Forearm - Superficial &
Intermediate
Muscle
Proximal Attachment
(Origin)
Distal Attachment
(Insertion)
Action
Nerves
Pronator teres
Medial epicondyle of
the humerus
Lateral midshaft of
radius
Pronates and
flexes the elbow
Median nerve
Flexor Carpi
Radialis (FCR)
Medial epicondyle of
the humerus
2nd metacarpal
Flexes and
abducts the wrist
Median nerve
Palmaris Longus
Medial epicondyle of
the humerus
Flexor retinaculum
and the palmar
aponeurosis
Flexes the wrist
and tightens the
palmar
aponeurosis
Median nerve
Flexor Carpi Ulnaris
(FCU)
Medial epicondyle of
the humerus
Pisiform, and 5th
metacarpal
Flexes and
adducts the wrist
Ulnar nerve
Flexor Digitorum
Superficialis (FDS) Inermediate layer
Medial epicondyle,
coronoid process of
the ulna and anterior
border of the radius
Lateral surfaces of
the middle phalanx
of digits 2-5
Flexes the wrist,
metacarpophalang
eal and proximal
interphalangeal
joints
Median nerve
2. Anterior Compartment (Flexor-Pronator) of The Forearm - Deep
Muscle
Proximal Attachment
(Origin)
Distal Attachment
(Insertion)
Action
Nerves
Flexor Digitorum
Profundus (FDP)
Medial surfaces of the
proximal ulna and
interosseous
membrane
Distal phalanx of
digits 2-5
Flexes joints from
the wrist to the
distal
interphalangeal
joints
- Medial part:
ulnar nerve
(C8-T1) Lateral part:
median nerve
(C8-T1)
Flexor Pollicis
Longus (FPL)
Radius
Distal phalanx of
digit one
Flexes the thumb
Median nerve
Pronator Quadratus
Distal anterior ulna
Distal anterior
radius
Pronates the
elbow
Median nerve
3. Posterior Compartment (Extensor-Supinator) of The Forearm - Superficial
Muscle
Proximal Attachment
(Origin)
Distal Attachment
(Insertion)
Action
Nerves
Brachioradialis
Lateral supracondylar
ridge of the humerus
Styloid process of
the radius
Flexes the elbow
Radial nerve
Extensor carpi
radialis longus
(ECRL)
Lateral supracondylar
ridge of the humerus
2nd metacarpal
Extends and
abducts the wrist
Radial nerve
Extensor carpi
radialis brecis
(ECRB)
Lateral epicondyle of
the humerus
3rd metacarpal
Extends the wrist
Posterior
interosseous
nerve, the
continuation of
the deep
branch of the
radial nerve
Extensor digitorum
Lateral epicondyle of
the humerus
Extensor expansion
of digits 2-5
Extends the wrist
and fi ngers
Extensor digiti
minimi (EDM)
Lateral epicondyle of
the humerus
Extensor expansion
of digit 5
Extends digit 5
Extensor Carpi
Ulnaris (ECU)
Lateral epicondyle of
the humerus
5th metacarpal
Extends and
adducts the wrist
4. Posterior Compartment (Extensor-Supinator) of The Forearm - Deep
Muscle
Proximal Attachment
(Origin)
Distal Attachment
(Insertion)
Action
Nerves
Supinator
Lateral epicondyle
and supinator crest of
the ulna
Distal to the radial
tuberosity
Supinates the
forearm
Deep branch of
the radial nerve
Extensor indicis
Ulna, radius and
interosseous
membrane
1st metacarpal
Abducts and
extends the thumb
Posterior
interosseous
nerve, the
continuation of
the deep
branch of the
radial nerve
Abductor Pollicis
Longus
Radius and
interosseous
membrane
Proximal phalanx of
digit 1
Extends the thumb
at the
carpometacarpal
joint
Extensor pollicis
longus (EPL)
Ulna and interosseous
membrane Lateral
epicondyle of the
humerus
Distal phalanx of
digit 1
Extends the thumb
Extensor polliicis
brevis (EPB)
Extensor
expansion of digit 2
Extends digit 2
Anconeus
Olecranon process
of the ulna
Extends the elbow
Radial nerve
MSK 05 - Hand
Clinical Correlates - Upper Limb
Clinical Correlates
1. Fracture Clavicle
Explanations
• Due to fall with an outstretched hand
• Medial fragment is pulled upward due to Sternocleidomastoid Muscle (SCM)
• The lateral fragment is pulled downward by weight of arm, medial and forward by the
adductors of the shoulder.
• Most vulnerable to fracture in all age groups. Most common fractured bone.
• The weakest point is the junction of the medial 2/3rd and lateral 1/3rd where the
fracture occurs.
2. Dislocation of AC &
SC Joint (+
Ankylosis of SC
joint)
●
●
●
3. Winging of Scapula
Dislocation of sternoclavicular joint
■ Age <25yo
■ # of medial end of clavicle through epiphyseal plate
Ankylosis of SC joint
■ Stiffening or fixation
Dislocation of AC joint
■ Contact sports / hard fall on shoulder / fall on outstretched limb
■ Tearing of coracoclavicular ligament
■ Acromion falls under clavicle
■ “shoulder separation”
• Lesion of long thoracic nerve
• Medial border positioned outward
• Inferior angle protrudes out
• Appearance of a wing
• Difficulty in raising arm above shoulder
Clinical Correlates
Explanations
4. Dropped Shoulder
• Paralysis of trapezius
• Lesion to spinal accessory nerve
5. Lesion to Dorsal
Scapular Nerve
• Affected muscles: Rhomboids major and minor
• On side that is affected, scapula located further from midline
6. Triangle of
Auscultation
• Scapula drawn anteriorly with arms brought forward and chest flexed
• Bounded by: Superior horizontal border of latissimus dorsi, Medial border of scapula,
Inferolateral border of trapezius
Clinical Correlates
7. Upper trunk injury (C5 &
C6)
Explanations
• Causes:
- a) In the young age, it is usually due to birth injuries when there is marked
traction on the head during delivery or shoulder dystocia
- b) In the adult, it is due to sudden and excessive lateral flexion of the head as
occurs when a person falls on the shoulder in a way that widely separates the
neck & shoulder.
• Motor Loss: Paralysis of deltoid, subscapularis, supraspinatus, infraspinatus, teres
minor, teres major, biceps, brachialis, brachioradialis & supinator.
• Deformity: Erb’s paralysis / waiter’s tip position
- a)The arm is adducted & medially rotated
- b) The forearm is extended and pronated
- c) The hand is flexed at the wrist
8. Lower trunk injury Klumpke’s Paralysis (C8 &
T1)
• Causes:
- a) Sudden & excessive hyper-abduction of the shoulder joint as occurs when a
person grasps something to prevent falling on the ground.
- b) Cervical rib which is an extra rib ‘abnormal rib’ which extends between the
seventh cervical vertebra to the 1st rib and may compress the lower trunk of the
brachial plexus.
- c) Direct trauma (cut wounds) to the floor of the axilla.
• Motor loss:
- a) Paralysis of the flexors of the wrist and fingers.
- b) Paralysis of the small muscles of the hand.
• Sensory loss: Loss of cutaneous sensation over the medial side of the arm and
forearm.
• Deformity: Complete claw hand
- a) Extension of the metacarpophalangeal joints
- b) Flexion of the interphalangeal joints
9. Medial Epicondylitis
• Golfer’s elbow, baseball elbow, suitcase elbow, forehand tennis elbow.
• Characterised by the pain from the elbow to the wrist on the inside (medial side) of the
elbow
• Caused by damage to the tendons that bend the wrist toward the palm
10. Lateral Epicondylitis
• Tennis elbow
• Swelling of the tendons (Extensor carpi radialis brevis) that bend your wrist backward
away from the palm.
Clinical Correlates
Explanations
11. Surgical neck fracture
(Humerus Fracture)
• Frequent site
• Usually by a direct blow to the area, or falling on an outstretched hand
• Axillary nerve and posterior circumflex artery are at risk.
12. Mid-shaft fracture
(Humerus Fracture)
• Mid-shaft fracture → Direct blow to the arm or fall on the outstretched hand
• Radial nerve and profunda brachii artery are at risk.
• Radial nerve injury
- Wrist drop
- Some sensory loss over the dorsal (posterior) surface of the hand, and the
proximal ends of the lateral 3 and a half fingers dorsally
13. Supracondylar fracture
(Humerus Fracture)
• Usually due to fall on an outstretched hand
• More common in children
• Brachial artery injury (direct or due to swelling) → ischemia → Volkmann’s ischemic
contracture (uncontrolled flexion due to fibrotic and short flexor muscles)
• Anterior interosseous nerve (branch of the median nerve), ulnar nerve or radial nerve
can also be damaged.
• Contents of the cubital fossa can be damaged in supracondylar fracture of humerus
(directly or by soft tissue swelling).
• Intercondylar fracture (due to a severe fall on the flexed elbow)
14. Biceps Brachii
• Dislocation of tendon of long head of biceps brachii
• Prolonged tendinitis or forceful flexion of the arm against excessive resistance (weight
lifters) -> Rupture of tendon of long head of biceps brachii
• Biceps tendinitis
- Usually due to repetitive microtrauma
- Sports involving throwing and use of a racquet
- Pain, tenderness, and crepitus
Clinical Correlates
Explanations
15. Fractures of the radius
and/or ulna
• Fractures of the radius and/or ulna are often incomplete in young children—they are
greenstick fractures.
• Fractures of both the radius and the ulna in adults are usually the result of severe
injury. A direct injury usually produces transverse fractures at the same level, usually in
the middle third of the bones.
• Isolated fractures of the radius or ulna also occur, a fracture of one bone is likely to be
associated with dislocation of the nearest joint.
16. Colles fracture &
Dinner fork deformity of
hand
• A complete transverse fracture of the distal 2 cm of the radius.
• This fracture at distal end of radius is a common in adults above 50 years of age.
• It occurs more frequently in women secondary to osteoporosis.
• The distal fragment is displaced dorsally (dinner fork deformity) and is often
comminuted (broken in pieces).
• The fracture results from forced extension of the hand, usually as the result of trying to
ease a fall by outstretching the upper limb.
17. Colles fracture
• Normally the tip of radial styloid process lies distal to that of the ulna, but in this
fracture the position of styloid-tips are reversed.
Clinical Correlates
Explanations
18.
•
19.
•
20.
•
Pharmacology
1. Skeletal Muscle Relaxant
2. NSAID