ANTERIOR, POSTERIOR COMPARTMENTS & CUBITAL

FOSSA

Dr. Kumar K. V.

Associate Professor

26.10.2009

Biceps brachii• Origin: long head,

supraglenoid tubercle; short head, coracoid process

• Insertion: radial tuberosity• Action: supinator of forearm,

flexor of elbow joint, weak flexor of should joint

Pronator teres• Origin: medical epicondyle of

humerus and deep fascia of forearm

• Insertion: middle of lateral surface of radius

• Action: pronation of forearm and flexion of elbow

Muscles of arm• Antererior

group– Biceps brachii

Coracobrachialis

– Brachialis

• Posterior group – triceps brachii

Musculocutaneous n.

Median n.Medial brachial cutaneous n.

Medial antebrachial cutaneous n.

Superior ulnar coleteral a.

Deep brachial a.

Ulnar n.

Ulnar n.

Biceps

Median n.

Musculocutaneous n.

Median n.

Axillary a.

Brachial a.

Medial antebrachial cutaneous n.

Medial brachial cutaneous n.

Deep brachial a.

Superior ulnar coleteral a.& Ulnar n.

Inferior ulnar coleteral a.

• Musculocutaneous

Distribution: Biceps brachii, brachalis and coracobrachialis ‘BBC nerve’; skin on anterior aspect of forearm

Brachial artery• Continuation of axillary

artery• Divides into radial and

ulnar arteries at level of neck of radius

• Branches – Deep brachial a. －

accompanies with radial nerve

– Superior ulnar collaeral a.

– － accompanies with ulnar nerve

– Inferior ulnar collateral a.

Radial artery and branches • Radial recurrent a. • Superfical palmar branch• Principal artery of thumb

Ulnar artery and branches• Ulnar recurrent a. • Common interosseous artery

– Anterior interossous a. – Posterior interosseous a.

Deep palmar branch

Supraspinatus

Axillary nerve in the quadrangular space

Triceps muscles

Tendon of Triceps

Ulnar n.

Teres Major

Deltoid

Unconeus

POSTERIOR COMPARTMENT

OF ARM

Triceps brachii• Origin: long head,

infraglenoid tubercle; lateral head, above groove for radial n., medial head, below groove for radial n.

• Insertion: olecranon of ulna

• Action: extends elbow joint), long head can extend and adduct shoulder joint

• Radial Nerve in the Arm & Forearm– Distribution:

Extensor muscles of arm and forearm, brachioradialis; skin on back of arm, forearm, and radial side of dorsum of hand and radial two and one-half fingers

– Injury: Wristdrop

Joints of the Upper Extremity

• Elbow Joint– Synovial – hinge– Diarthrosis

• Articulations– Humerus & Ulna– Humerus & Radius

• Many Ligaments

Cubital fossaBoundaries • Base － line drawn

through epicondyles of humerus

• Apex － brachioradialis laterally and pronator teres medially

• Roof － skin, superficial fascia, deep fascia and aponeurosis of biceps

• Floor － brachialis, supinator and capsule of elbow joint

Contents from lateral to medial

• Biceps brachii tendon

• Brachial a.divides into radial and ulnar a.usually at apex of fossa

• Median n.

Lateral to the biceps brachii tendon,radial n. and lateral antebrachial cutaneous n.

• Basilic vein– Arises from the medial side

of the dorsal venous arch of hand

– Ascends on the ulnar side of forearm to the elbow and then in the medial bicepital brachii furrow to middle of the arm where it pierces the deep fascia and joins the brachial vein or axillary vein

• Median cubital vein links cephalic vein and basilic vein in the cubital fossa. It is a frequent site for venipuncture to remove a sample of blood or add fluid to the blood

Anterior Compartment Forearm

Flexor Carpi Radialis

Flexor Retinaculum

Medial Epicondyle

Flexor Digitorum Superficialis is deep to other flexors

Flexor Carpi Ulnaris

BrachioradialisPronator Teres

Anterior View

Muscles of forearm

• Superficial layer– Brachioradialis– Pronator teres– Flexor carpi radialis– Palmaris longus– Flexor carpi ulnaris

Muscolocutaneous n.

Brachial a.

Radial n.

Radial a.

Median n.

Common interosseous a.

Ulnar a., v. & n.

FOREARM VESSELS &NERVES

Radial recurrent a.

Radial a.

Radial n.

Median n.

Ulnar n.

Ulnar a.

Ulnar recurrent a.

Ulnar n.

Brachial a.

CUBITAL NERVES &ARTERIES

Superficial Layer:

(1) Pronator teres, (2) flexor carpi radialis, (3) palmaris longus, (4) flexor digitorum superficialis and (5) flexor carpi ulnaris.

Deep Layer:

(1) Flexor pollicis longus, (2) flexor digitorum profundus and (3) pronator quadratus.

Muscles of the Anterior Compartment of Muscles of the Anterior Compartment of the forearmthe forearm

Pronators of thePronators of theforearmforearm

Pronator teresOrigin:Origin:

Humeral head:Humeral head: from the medial epicondyle of the humerus from the medial epicondyle of the humerus (common flexor origin).(common flexor origin).Ulnar head:Ulnar head: from the medial border of the coronoid from the medial border of the coronoid process of the ulna.process of the ulna.

Insertion:Insertion:Into the pronator tuberosity on the lateral surface of the Into the pronator tuberosity on the lateral surface of the middle part of the shaft of the radius.middle part of the shaft of the radius.

Nerve Supply:Nerve Supply:From the median nerve.From the median nerve.

Action:Action:Pronation of the forearm at the radio-ulnar joints.Pronation of the forearm at the radio-ulnar joints.

Flexion of the forearm at the elbow jointFlexion of the forearm at the elbow joint..

Flexor carpi

radialis

Flexor digitorum superficialisFlexor digitorum superficialis Origin:Origin:

1.1. Humero-ulnar head:Humero-ulnar head: from the medial epicondyle of the from the medial epicondyle of the humerus (common flexor origin) and from the medial humerus (common flexor origin) and from the medial border of the coronoid process of the ulna.border of the coronoid process of the ulna.

2.2. Radial head:Radial head: from the oblique line on the anterior surface from the oblique line on the anterior surface of the shaft of the radius.of the shaft of the radius.

Insertion:Insertion:• Its tendon divides into 4 tendons which are inserted into Its tendon divides into 4 tendons which are inserted into

the sides of the middle phalanges of the medial 4 fingers.the sides of the middle phalanges of the medial 4 fingers. Nerve Supply:Nerve Supply:

• From the median nerve.From the median nerve. Action:Action:

1.1. Flexion of the proximal interphalageal joints and Flexion of the proximal interphalageal joints and metacarpophalangeal joints of the medial 4 fingers.metacarpophalangeal joints of the medial 4 fingers.

2.2. Helps of flexion of the hand at the wrist joint.Helps of flexion of the hand at the wrist joint.

Flexor digitorum profundusFlexor digitorum profundus Origin:Origin:

• From the upper ¾ of the anterior surface of the shaft of the ulna From the upper ¾ of the anterior surface of the shaft of the ulna and adjoining part of the interosseus membrane.and adjoining part of the interosseus membrane.

Insertion:Insertion:• The muscle divides into 4 tendons which pierce the tendons of The muscle divides into 4 tendons which pierce the tendons of

the flexor digitorum superficialis and are inserted into the bases the flexor digitorum superficialis and are inserted into the bases of the distal phalanges of the medial 4 fingers.of the distal phalanges of the medial 4 fingers.

Nerve Supply:Nerve Supply:• Its lateral half:Its lateral half: from the anterior interosseus nerve (branch of from the anterior interosseus nerve (branch of

the median nerve).the median nerve).• It medial half:It medial half: from the ulnar nerve. from the ulnar nerve.

Action:Action:1.1. Flexion of the distal interphalangeal joints of the medial 4 Flexion of the distal interphalangeal joints of the medial 4

fingers.fingers.2.2. Helps in flexion of the proximal interphalangeal joints and Helps in flexion of the proximal interphalangeal joints and

metacarpophalangeal joints of the medial 4 fingers.metacarpophalangeal joints of the medial 4 fingers.3.3. Helps of flexion of the hand at the wrist joint.Helps of flexion of the hand at the wrist joint.

BrachioradialisOrigin:

from the upper 2/3 of the lateral supracondylar ridge of the humerus.

Insertion:Into the base of the styloid process of the radius.

Nerve Supply:From the radial nerve.

Action:Flexion of the forearm (specially in midprone

position).Restoration of the forearm into the midprone

position.

Extensor Extensor CompartmentsCompartments

Of the Forearm &Of the Forearm &The HandThe Hand

Extensor digitorumOrigin:

from the lateral epicondyle of the humerus (common extensor origin).

Insertion:Into the extensor expansion of the medial 4

fingers.Nerve Supply:

From the deep branch of radial nerve.Action:

Extension of metacarpophalangeal and interphalangeal joints of the medial 4 fingers.

Extension of the hand at wrist joint.

SupinatorOrigin:Origin:

from (1) the lateral epicondyle of the humerus, (2) from (1) the lateral epicondyle of the humerus, (2) lateral collateral ligament of the elbow joint, (3) lateral collateral ligament of the elbow joint, (3) annular ligament of the superior radio-ulnar joint, annular ligament of the superior radio-ulnar joint, and (4) supinator fossa and crest of the ulna.and (4) supinator fossa and crest of the ulna.

Insertion:Insertion:

Into the upper 1/3 of the lateral surface of the shaft of Into the upper 1/3 of the lateral surface of the shaft of the radius.the radius.

Nerve Supply:Nerve Supply:

From the deep branch of the radial nerve.From the deep branch of the radial nerve.

Action:Action:

It helps the biceps in supination of the forearm at the It helps the biceps in supination of the forearm at the radio-ulnar joints.radio-ulnar joints.

Deep palmar fascia

Superficial layer• Thenar fascia• Hypothenar fascia• Palmar aponeurosis thick

triangular membrane

Deep layer palmar interosseous fascia

Palmar aponeurosis

Carpal TunnelFlexor retinaculum• Thickening of deep fascia in the

hand• Attached laterally to scaphoid and

trapeziun and medially to pisiform and hamate

Carpal tunnel Formed by flexor retinaculum and carpal groove

• Transmits– Median n.– Flexor digitorum superficialis and

flexor digitorum profundus enclosed by common flexor sheath

– Flexor pollicus longus enclosed by tendinous sheath of flexor pollicus longus

Flexar Retinaculum & related structures

Common flexor sheath

Tendinous sheath of flexor pollicis longus

Muscles of hand• Lateral group － thenar (4)

– Abductor pollicis brevis– Flexor pollicis brevis– Opponens pollicis– Adductor pollicis

• Action: flex, abduct, adduct and oppose thumb

• Medial group － hypothenar (3)– Abductor digiti minimi– Flexor digiti minimi

brevisOpponens digiti minimi– Action: flex, abduct , and

oppose little finger

Superficial palmar arch• Formed by ulnar artery

and superficial palmar branch of radial artery

• Curve of arch lies across the palm, level with the distal border of fully extended thumb

• Gives rise to three common palmar digital arteries each then divides into two proper palmar digital arteries

Superficial palmar a.

recurrent n.

Ulnar a.

Superficial Palmar Arterial Arch

Nerves, Vessels & Hand Muscles

Deep palmar arch• Formed by radial artery

and deep palmar branch of ulnar artery

• Curve of arch lies across upper part of palmar at level with proximal border of extended thumb

• Gives rise to three palmar metacarpal arteries

Intermedial group• Lumbricales (4) － flex

fingers at MP joints; extend fingers at IP joints

• Palmar interossei (3) － adduct fingers towards middle finger at MP joints

• Dorsal interossei (3) －abduct fingers away from middle finger at MP joints

Intrinsic Muscles of Hand

ABduction

Palmar Interossei

Lumbricals

ADDuction

1st

2nd

3rd

4th

Dorsal Interossei

Interossei help the lumbricals to extend IP joints and flex MC-P joints

Lumbricals & Nerves

Anatomical snuff box

• When the thumb is abducted and extended, a triangular hollow appears between the tendon of the extensor pollicis longs medially and the tendons of the extensor pollicis brevis and abductor pollicis longus laterally.

• The floor of the snuff box is the scaphoid and trapezium bones and crossed by the radial a..

Extensor Retinaculum & Dorsum of Hand

Dorsum of handExtensor retinaculum• Thickening of deep faxcia of

forearm a wrist

• Attached laterally to radius and medially to styloid process of ulna and triquetrum

• Forms six fibrous compartments for extensor tendons passing from forearm into hand:

• tendons of abductor pollicis longus and extensor pollicis brevis and their synovial sheaths;

• tendons of extensor carpi radialis longus and brevis and their synovial sheaths;

• tendon of pollicis longus and its synovial sheath;

• tendons of extensor digitorum, extensor indicis and their synovial sheaths;

• tendon of extensor digiti minimi and its synovial sheaths;

• tendon of extensor carpi ulnaris and its synovial sheaths

Fascia of the dorsal hand

• The superficial fascia• Deep fascia － the

dorsal fascia of hand– Superficial layer (dorsal

aponeurosis) – Deep layer (dorsal

interosseous fascia)

Two spaces• The dorsal subcutaneous space• The dorsal subaponeurotic space

Superficial fascia

Dorsal aponeurosis

Dorsal interosseous fascia

Dorsal subcutaneous space

Dorsal subaponeurotic space

Nerves of hand • Median n. － thenar except adductor pollicis, first two

lumbricals; skin of thenar, central part of palm, palmar aspect of radial three and one-half fingers, including middle and distal fingers on dorsum

• Ulnar n. － hypothenar muscles, interossei, 3rd and 4th lumbricals and adductor pollicis; skin of hypothenar, palmar surface of ulnar one and one-half fingers

• Radial n. skin of radial side of dorsum of hand and radial two and one-half fingers

Intrinsic Muscles of Hand

• Little finger– All digiti minimi Ulnar

(Flexor, Abductor, Opponens)

• Thumb– Abductor pollicis brevis Median– Flexor pollicis brevis Median– Opponens pollicis Median– Adductor pollicis Ulnar

• Other Intrinsic Muscles– Palmar + Dorsal Interossei Ulnar– Lumbricals Median, Ulnar

Muscle Nerve