Gross Anatomy: MUSCLE (UPPER LIMB)

[O] Origin, [I] Insertion, [A] Action, [NS] Nerve Supply, [NR} Nerve root

Pectoralis Major

O: Clavicular head, Sternocostal Head

I: Bicipital groove

A: Adduction, medial rotation and flexion
NS: Medial pectoral nerve (sternocostal head) and lateral pectoral nerve (clavicular head)
NR: C5-C8-T1

Pectoralis Minor

O:3rd-5th ribs
I: Coracoid process

A: Scapular movement:

● Protraction (pull forward)

● Depression (pull down)

● Stabilization

When the scapula is stabilized, it can

elevate the 3rd–5th ribs, which expands

the chest cavity and assists with deep

breathing.

NS: Medial Pectoral Nerve

NR: C6,C7,C8

Subclavius

O: 1st Rib

I: Inferior border of the clavicle

A: Depression and stabilization of the clavicle

● elevation of the 1st rib

NS: Nerve to subclavius

NR: C5,C6

Serratus Anterior

O: Lateral Ribs

I: Vertebral border

A: Scapular Movement:

● Protraction and upward rotation

● Stabilization (anchoring to ribs)

NS: Long thoracic Nerve

NR: C5-C7

Trapezoid- Descending Fiber

O: Medial 1/3 of the superior nuchal line, occipital bone

I: Lateral 1/3 of the Clavicle

A: Scapular elevation

NS: Accessory Nerve

NR: Cranial Nerve XI

Trapezoid-Transverse Fiber

O: C7-T3

I: Acromion Process

A: Scapular retraction

NS: Accessory Nerve

NR: CN XI

Trapezoid- Ascending FIber

O:T4-T12

I: Medial Scapular Spine

A: Scapular depression

NS: Accessory nerve

NR: CN XI

Latissimus Dorsi

O:

● Vertebrae: Spinous processes of the

7th thoracic to 5th lumbar vertebrae.

● Thoracolumbar fascia

● Iliac crest: Posterior portion of the hip

bone

● Ribs: Lower 3-4 ribs

● Scapula: Inferior angle

I: Bicipital groove

A: Extension, adduction and medial rotation of arm

NS: Thoracodorsal Nerve

NR: C6-C8

Levator Scapulae

O: Transverse processes of the

first four cervical vertebrae

I: Superior Medial border of scapula

A:

● Elevate the scapula (e.g., shrugging)

● Contributes to lateral flexion and

extension of the neck

● Aids in stabilization of scapula

NS: C3 and C4

Dorsal scapular nerve (C5)

NR: C3-C5

Rhomboid Major

O: 2nd–5th thoracic spines

I: Medial border of scapula

A: Retract and elevate the scapula

(stabilizing it against the ribcage)

NS: Dorsal scapular nerve (C5)

NR: C4 AND C5

Rhomboid Minor

O: Nuchal ligament

Spinous processes of the C7 and T1

vertebrae

I: Medial Border of Scapula

A: Retract and elevate the scapula

NS: Dorsal Scapular nerve

NR: C4 and C5

Deltoid—Anterior Fiber

O: Lateral 1/3 of the Clavicle

I: Deltoid Tuberosity

A: Flexion and medial rotation of the shoulder

NS: Axillary nerve, Lower half is supplied by the upper and lateral cutaneous nerve of arm

NR: C5,C6

Deltoid—Middle Fiber

O: Acromion Process

I: Deltoid Tuberosity of the humerus

A: Shoulder abduction

NS: Axillary nerve, Lower half is supplied by the upper and lateral cutaneous nerve of arm

NR: C5,C6

Deltoid—Posterior Fiber

O: Spine of the Scapula

I: Deltoid tuberosity of the humerus

A: Extension and lateral rotation

NS: Axillary nerve, Lower half is supplied by the upper and lateral cutaneous nerve of arm

NR: C5,C6

Supraspinatus

O: Supraspinous Fossa of the Scapula

I: Greater tuberosity of humerus

Shoulder joint capsule

A: Initiates abduction of the shoulder joint

Externally rotates the humerus

NS: Suprascapular nerve

NR: C4-C6

Infraspinatus

O: Infraspinous fossa of the scapula

I: Greater tuberosity of humerus; Shoulder

joint capsule

A: External rotation of the humerus

Stabilizes the shoulder joint

NS: Suprascapular nerve

NR: C4, C5, C6

Teres Minor

O: Upper two thirds of the lateral border of the scapula

I: Greater tuberosity of the humerus, Shoulder joint capsule

A: External rotation of the humerus, Stabilizes the shoulder joint

NS: Axillary Nerve

NR: C4-C6

Subscapularis

O: Subscapular fossa

I: Lesser Tuberosity of humerus

A: Internal rotation of the humerus, Stabilizes the shoulder joint

NS: Upper and Lower subscapular nerves

NR: C5-C7

Teres Major

O: Lower third of lateral border of scapula

I: Medial lip of bicipital groove of humerus

A: Adduction, medial rotation, and extension of the humerus, Stabilizes shoulder joint

NS: Lower subscapular nerve

NR: C6,C7

Biceps Brachii

O: [Long Head] lateral Tendon, [Short Head] Medial Tendon

I: Radial Tuberosity( Bicipital tuberosity) of the radius

A: Strong flexor of the elbow joint(at supinated position), Weak flexor of the shoulder joint

NS:

NR:

Coracobrachialis

O: Coracoid Process of Scapula

I: Medial Aspect of humeral shaft

A: Shoulder flexion, adduction of the arm

Brachialis

O: Distal, anterior surface of humerus

I: Coronoid Process of Ulna

A: Elbow Flexion

Triceps Brachii—Long Head

O: Infraglenoid Tubercle of Scapula

I: Olecranon Process of Ulna

A: Primary extensor of elbow joint

Triceps Brachii—Lateral Head

O: Upper Hald of Posterior, surface of shaft of humerus

I: Olecranon Process of Ulna

A: Primary extensor of elbow joint

Triceps Brachii—Medial Head

O: Lower half of posterior surface of shaft of humerus

I: Olecranon Process of Ulna

A: Primary Extensor of elbow joint

Pronator Teres

O:

• Humeral Head — Medial supracondylar ridge of the humerus

• Ulnar Head — Coronoid Process of the Ulna

I: Lateral Surface of the radius

A: Pronation, Elbow Flexion

Palmaris Longus

O: Medial Epicondyle of the humerus

I: Flexor retinaculum and Palmar aponeurosis

A: Wrist flexion, Tenses Palmar aponeurosis

Flexor Carpi Ulnaris

O:

• Humeral Head— Medial epicondyle of Humerus

• Ulnar Head— Medial aspect

I: Pisiform, Hook of Hamate, Base of the 5th Metacarpal

A: Wrist flexion and adduction

Flexor Carpi Radialis

O: Medial epicondyle of humerus

I: Base of the 2nd and 3rd Metacarpal

A: Flexes and abducts hand at the wrist

Flexor Digitorum Superficialis

O:

• Humeroulnar Head: Medial epicondyle of humerus, medial border of the coronoid process of the ulna

• Radial Head: Oblique line on anterior surface of shaft of radius

I: Middle phalanges of medial four fingers

A: Flexion of middle phalanx, Assist in Flexion of proximal phalanx and hand

Flexor Digitorum Profundus

O:Anteromedial surface of ulnar shaft

I: Distal phalanges of medial four fingers

A: Flexion of distal phalanx, Assist in flexion of middle and proximal phalanges and wrist

Flexor Pollicis Longus

O: Anterior Surface of Radius Shaft

I: Distal Phalanx of Thumb

A: Flexion of distal phalanx of thumb

Pronator Quadratus

O: Anterior Surface of Ulnar Shaft

I: Anterior surface of radial shaft

A: Pronation of the radioulnar joint, Stabilization of the radioulnar connection

Brachioradialis

O: Lateral supracondylar ridge of humerus

I: Base of styloid process of radius

A: Forearm flexion at elbow joint, Rotation of forearm to the midprone

position

Extensor Carpi Radialis Longus(ECRL)

O: Lateral supracondylar ridge of humerus

I: Posterior surface of base of 2nd metacarpal bone

A: Wrist extension and abduction, Capable of radial deviation

Extensor Carpi Radialis Brevis(ECRB)

O: Lateral Epicondyle of Humerus

I: Posterior surface of base of 3rd metacarpal bone

A: Extends and abducts hand at wrist joint

Extensor Digitorum

O: Lateral epicondyle of Humerus

I: Middle and distal phalanges of medial four fingers

A: Extension of fingers and hand

Extensor Digiti Minimi

O:Lateral epicondyle of humerus

I: Extensor expansion of little finger

A: Extends metacarpophalangeal joint of little finger

Extensor Carpi Ulnaris Muscle

O: Lateral epicondyle of Humerus

I: Base of 5th Metacarpal bone

A: Wrist Extension and adduction, Capable of ulnar deviation

Anconeus

O: Lateral epicondyle of humerus

I: Lateral surface of olecranon process of ulna

A: Extends elbow joint

Suppinator

O: Lateral Epicondyle of humerus

I: Nech and shaft of the radius

A: Supinates the forearm

Extensor Indicis

O: Posterior surface of ulnar shaft

I: Extensor expansion of index finger

A: Extension of metacarpophalangeal(MCP) joint of index finger

Anatomical Snuffbox

Comprised of the:

Abductor Pollicis Longus
Extensor Pollicis Brevis(EPB)
Extensor Pollicis Longus(EPL)

Abductor Pollicis Longus(APL)

O: Posterior surface of radial and ulnar shafts
I: Base of 1st metacarpal
A: Abduction and extension of thumb

Extensor Pollicis Brevis

O: Posterior surface of radial shaft

I: Base of proximal phalanx of thumb

A: Extends MCP joint of thumb

Extensor Pollicis Longus

O: Posterior surface of ulnar shaft

I: Base of Distal phalanx of thumb

A: Extension of distal phalanx of thumb

Antecubital Fossa

Inverted, triangle-shaped depression anterior to the

elbow

Lateral Border—brachioradialis
Medial Border— pronator teres
Apex is formed by Pronator teres and brachioradialis
Base—imaginary line cross epicondyles of humerus

Thenar Eminence

O: Scaphoid, Trapezium and Flexor retinaculum

I: Base of proximal phalanx of thumb

A: Abduction of thumb

NS: Median Nerve

NR: C8-C11

Flexor Pollicis Brevis

O: Flexor retinaculum

I: Base of proximal phalanx of thumb

A: Flexion of the MCP joint of thumb

NS: Median Nerve

NR: C8,T1

Opponens Pollicis

O: Flexor retinaculum

I: Distal shaft of the 1st metacrapal(thumb)

A: Opposition

NS: Median Nerve

NR: C8, T1

Adductor Pollicis

O:

• Oblique Head: 2nd and 3rd Metacarpals

• Transverse Head: 3rd metacarpal

I: Base of the proximal phalanx of thumb

A: adduction of thumb

NS: Deep branch of ulnar nerve

NR: C8, T1

Abductor Digiti Minimi

O: Pisiform

I: Base of proximal phalanx of little finger

A: Abduction of the little finger

NS: Deep branch of ulnar nerve

NR: C8 and T1

Flexor Digiti Minimi

O: Flexor Retinaculum

I: Base of promximal MCP of little finger

A: Flexion of the little finger

NS: Deep branch of ulnar nerve

NR: C8, T1

Opponens Digiti Minimi

O: Flexor Retinaculum

I: Medial border of 5th metacarpal bone

A: Pulls 5th metacarpal forward as in

cupping the palm

NS: Deep branch of ulnar nerve

NR: C8, T1

Lumbricals

O: Tendons of flexor digitorum profundus

I: Extensor expansion of medial four fingers

A: Flexion of MCP joints, Extend IP joints of fingers except thumb

NS:

• 1st and 2nd (lateral): Median nerve

  3rd and 4th (medial): Deep branch of

  ulnar nerve

NR: C8, T1

Interosseus Compartment

FORMED: palmar and dorsal interosseous muscles.

RESPONSIBLE: finger adduction and abduction.

Palmar Interossei

O: 1st – base of 1st metacarpal

Remaining three – anterior surface of shafts of 2nd, 4th, and 5th metacarpals

I: Proximal phalanges of thumb, index ring, and little fingers Dorsal extensor expansion of each finger

A:

• Adduction (towards the third finger)

  Both dorsal and palmar interossei flex

  MCP joints and extend IP joints

NS: Deep branch of ulnar nerve

NR: C8, T1

Dorsal Interossei

O: Continuous sides of shafts of metacarpals

I: Proximal phalanges of index, middle, and ring fingers,Dorsal extensor expansion

A:

• Finger abduction (from middle finger)

• Both dorsal and palmar interossei

• flex MCP joints and extend IP joints

NS: Deep Branch of ulnar nerve

NR: C8, T1

Central Compartment

Composed of 4 Lumbrical Muscles

Interosseus Compartment

Formed by palmar and dorsal interosseus muscles
Responsible for finger adduction and abduction

Hypothenar Eminence

3 short muscles located at the ulnar side of the hand

AFO + digiti minimi

Thenar Eminence

Fleshy mound at the base of the thumb

AFO + pollicis

Antecubital Fossa

Inverted, triangle shaped depression anterior to the elbow

Lateral Border—brachioradialis

Medial Border—Pronator Teres

Base—Imaginary line crossing the epicondyles of the humerus
Floor— Brachialis(Proximally), Supinator(Distally)
Contents—Biceps Brachii

Anterior Palmar Ligament

Covers all the tendons in the wrist area

Flexor Retinaculum

The ligament which forms the root of that cavity— forming the carpal bone configuration forming a concavity

Extensor retinaculum

Holds the tendons of the posterior fascial compartment

Axilla

Known as the armpit

Pyramind-shaped space between the upper arm and the side of the chest

Pectoralis Major, Pectoralis Minor and Subclavius

Anterior border of the axilla

Latissimus dorsi, Subscapularis and Teres Major

Posterior border of the axillary inlet

Serratus anterior and upper 4 or 5 ribs

Medial Border of the axilla inlet

biceps brachii and coracobrachialis

Lateral border of the axillary inlet