Upper Limb Anatomy

Last updated 20.09.12

Index

- Bones

- Joints

- Movements & ROM

- Muscles

- Fascia

- Trigger Points

- Arterial Supply

- Venous Drainage

- Lymphatic Drainage

- Innervation

- Cutaneous Innervation

- Dermatomes

- Reflexes

- Regional Anatomy

- Surface Anatomy

- Acupuncture

Bones of the Upper Limb

<Upper Limb Anatomy>

- Clavicle

- Scapula

- Humerus

- Ulna

- Radius

- Carpals

- Scaphoid

- Lunate

- Triquetral

- Pisiform

- Trapezium

- Trapezoid

- Capitate

- Hamate

- Metacarpals

- Phalanges

- Proximal

- Middle

- Distal

Humerus

- Longest of upper limb bones

- Sole bone of (upper) arm (brachium)

- 2 bones bilaterally, 1 each side

- Head

o Proximal end of humerus

o Ball shaped

o Articulates with glenoid cavity of scapula postereo-medially at an angle of about 10^o postereo-medially

o Covered by fibrocartilage

o Lies within the glenohumeral joint capsule to from the glenohumeral joint

- Anatomical Neck

o Separates the head from the tubercules

o Lies proximal to the surgical neck and to the greater and lesser tubercules

o Attachment site of the glenohumeral joint capsule

§ Coracohumeral Ligament superiorly

§ Glenohumeral Ligaments (3 components) anteriorly

· Superior Glenohumeral Ligament

· Middle Glanohumeral Ligament

· Inferior Glenohumeral Ligament

- Greater Tubercule of the humerus

o Lies on the lateral aspect of the head

o Forms the lateral aspect of the shoulder in the anatomical position

o Attachment site for:

§ Supraspinatus muscle at superior facet

§ Infraspinatus muscle at middle facet

§ Teres minor muscle at inferior facet

o Connected to the lesser tubercule of the humerus by the transverse humeral ligament

o Lies lateral to the lesser tubercule of the humerus

- Lesser Tubercule of the humerus

o Lies on the anterior and slightly medial aspect of the head of the humerus

o Attachment site for the subscapularis muscle

o Connected to the greater tubercule of the humerus by the transverse humeral ligament

- Greater and lesser tubercules form the insertions of the rotator cuff muscles onto the humerus

- Intertubercular Groove (Bicepital Groove)

o Runs vertically between the greater tubercule and lesser tubercule of the humerus on anterior aspect of humerus

o Occupied by the tendon of the long head of biceps brachii

o Traversed at its most superior aspect by the transverse humeral ligament

o Inferior to the transverse humeral ligament the intertubercular groove acts as attachment site of:

§ Pectoralis major muscle on its lateral lip

§ Latissimus dorsi muscle on its floor

§ Teres major muscle on its medial lip

§ Remembered by “A Lady (Latissimus dorsi) lies between two Majors (pectoralis Major and teres Major)”

- Surgical Neck

o Area of the humerus where the anatomical neck tapers to form the body

o Distal to the anatomical neck

o Area most prone to fractures

o Surrounded by axillary nerve, posterior humeral circumflex artery and anterior humeral circumflex artery

- Shaft

o Superior half is cylindrical

o Deltoid Tuberosity

§ On the anterior lateral aspect of the humerus just proximal to the midpoint of the humerus

§ Attachment site for the deltoid muscle

o Radial Groove (Sprial Groove)

§ Shallow groove which runs obliquely from the posterior medial aspect inferiolaterally around to the anterior surface of the humerus

§ Covered by the triceps brachi muscle

§ Contains the radial nerve and profundi brachi artery

o Nutrient Canal

§ Anteriomedial surface of humerus

§ Receives nutrient humeral artery

- Distal End

o Inferiorly expands medially and laterally into the sharp edges of the medial and lateral supracondylar ridges

o Lateral Supracondylar Ridge

§ Distal continuation of the lateral shaft of the humerus

§ Forms the lateral epicondyle of the humerus

§ Attachment site of:

· Brachioradialis muscle proximally

· Extensor carpi radialis longus muscle distally

o Lateral Epicondyle

§ Most lateral aspect of the distal end of the shaft of the humerus

§ Attachment site of:

· Ulnar lateral collateral ligament

· Brachial fascia

· Supinator muscle

· Common tendinous origin of the forearm extensors

o Extensor carpi radialis brevis muscle most lateral

o Extensor digitorum muscle central

o Extensor digiti minimi muscle as a small medial portion of extensor digitorum

o Extensor carpi ulnaris muscle most medial

o Aconeus muscle posteriomedially (short muscle)

§ Projects laterally from the capitulum

o Capitulum (Lateral Condyle) (L. small head)

§ Inferior distal aspect of the humerus

§ Articulates with the head of the radius inferiorly at the radiohumeral joint

§ Ball shaped and lies lateral to the trochlea

o Trochlea (Medial Condyle) (L. spindle)

§ Inferior distal aspect of the humerus

§ Fits into the trochlear notch of the ulna at the radiohumeral joint

§ Lies medial to the capitulum

o Coronoid Fossa

§ Shallow fossa larger and medial to the radial fossa

§ Lies superior to the trochlea on the anterior aspect of the humerus

§ Depression which receives the coronoid process of the ulna in elbow flexion

o Radial Fossa

§ Shallow fossa smaller and lateral to the coronoid fossa

§ Lies superior to the trochlea on the anterior aspect of the humerus

§ Depression which receives the coronoid process of the ulna in elbow flexion

o Medial Epicondyle

§ Most medial aspect of the distal extremity of the humerus

§ Attachment site of:

· Ulnar medial collateral ligament

· Brachial fascia

· Common tendinous origin of the wrist flexors

o Flexor carpi radialis muscle

o Palmaris longus muscle

o Humeral head of felxor carpi ulnaris muscle

o Humeroulnar head of flexor digitourm superficialis muscle

§ Projects medially from the trochlea

§ Larger and more protrusive than the lateral epicondyle

o Retrocondylar Groove

§ Lies posterior to the medial epicondyle

§ Contains the ulnar nerve

§ Site of anastomoses of superior ulnar collateral artery with inferior ulnar collateral artery and posterior ulnar recurrent artery

o Medial Supracondylar Ridge

§ Distal continuation of the medial shaft of the shaft of the humerus

§ Forms the medial epidondyle

§ Attachment site of pronator teres muscle proximal to common flexor origin on medial epicondyle

o Olecranon Fossa

§ Deep fossa

§ Lies superior to the trochlea on the posterior aspect of the humerus

§ Depression which receives the olecranon process of the ulna in elbow extension

Ulnar (L. elbow):

- Longer of the 2 forearm (antebrachium) bones

- Lies medial to the radius in the anatomical position

- 2 bones bilaterally, 1 each side

- Similar in shape to a wrench

o Olecranon as the upper jaw proximally

o Coronoid process the lower jaw

o Trochlea notch as the mouth

o Shaft as the handle distally

- Proximal Extremity (Base)

o Olecranon Process

§ Prominence of the elbow joint

§ Most anterosuperior portion fits into the olecranon fossa of the humerus

§ Is covered superficially by the superficial olecranon bursa

§ Most proximal aspect of ulna

§ Attachment site of:

· Brachial fascia

· Triceps brachi muscle

· Aconeus muscle

· Flexor carpi ulnaris muscle

· ????

o Trochlear Notch

§ Concave surface between the distal aspect of olecranon process and proximal aspect of coronoid process

§ Fits around the trochlea of the humerus at the humeroulnar joint

§ Is covered by cartilage

o Coronoid Process

§ Distal to the trochlea notch on the anterior aspect of the ulna

§ Fits into the coronoid fossa of the humerus

§ Attachment site of:

· Flexor digitorum superficialis muscle on its medial edge

§ Radial Notch

· Lies on lateral aspect of coroind process

· Small shallow depression

· Receives the disc shaped head of the radius at the proximal radioulnar joint

o Ulnar Tuberosity

§ Distal to the coronoid fossa on the anterior aspect of the ulna

§ Attachment site of:

· Brachialis muscle

· Ulnar head of pronator teres muscle medial to brachialis muscle

o Supinator Fossa

§ Lies distal to the radial notch on the lateral aspect of the ulna

§ Triangular depression

§ Attachment site for the supinator muscle

o Supinator Crest

§ Lies on the medial aspect of the ulna distal to the radial notch

§ Sharp posteriomedial border of the supinator fossa

- Shaft

o Decreases in size proximal to distal with a slight lateral convexity

o Attachment site of flexor digitorum profundus muscle proximal three quarters of anterior aspect

o Interosseous Border

§ Sharp lateral edge

§ Attachment of the interosseous membrane between the radius and ulna

- Head

o Distal extremity of ulna

o Rounded and slender

o Lateral surface is convex where it articulates with the ulnar notch of the radius at the distal radioulnar joint

o Pronator Crest

§ Distal quarter of anterior surface

§ Attachment site of pronator quadratus muscle

o Styloid Process

§ Conical in shape

§ Projects distally, not as far distal when compared to the styloid process of the radius

o Inferior distal surface

§ Does not articulate with the carpal bones

§ Articulates with the articular disc of the distal radioulnar joint

Radius (L. spoke of a wheel)

- Shorter of the 2 forearm (antebrachium) bones

- Lies lateral to the ulna in the anatomical position

- 2 bones bilaterally, 1 each side

- Radial Head

o proximal extremity of radius

o disc shaped and articulates medially with the ulna at the proximal radioulnar joint

o Fovea

§ Cup like depression at superior surface

§ Articulates with the capitulum of the humerus at the humeroradial articulation

o Radial Neck

§ Smooth and cylindrical

§ Joins the head of the radius with the body inferiorly

o Attachment site of:

§ Supinator muscle lateral and distal to the radial tuberosity on lateral aspect

- Shaft

o Radial Tuberosity

§ Distal to the neck on the medial aspect of the anterior radius

§ Attachment site of biceps brachii

o Body increases in size proximal to distal with a slight lateral convexity

o Concave anteriorly at its proximal three quarters and flattens in its distal quarter

o Anterior Oblique Line of the radius

§ Runs obliquely across the anterior aspect of the body of the radius from the radial tuberosity to the area of the greatest curvature

§ Attachment site of:

· Flexor digitorum superficialis muscle through most of its length

· Pronator teres muscle at the lateral edge

o Posterior Oblique Line of the radius

§ Runs

o Attachment site of:

§ Flexor pollicis longus muscle middle half of anterior surface distal to anterior oblique line

o Interosseous Border of the radius

§ Lies at the sharp medial edge

§ Attachment of the interosseous membrane between the radius and ulna

o Lateral border of the radius is rounded

- Distal Extremity

o Larger than its proximal head

o Larger than the distal extremity of the ulna

o Attachment site of:

§ Brachioradialis muscle just proximal to the styloid process on the lateral aspect

§ Pronator quadratus muscle proximal to the styloid process on the anteromedial aspect

o Ulnar Notch

§ Shallow depression on medial surface

§ Receives head of ulna at distal radioulnar joint

o Styloid Process of the radius

§ Pyramidal in shape

§ A prolongation of the distal extremity of the radius

§ Projects distally further distal when compared to the styloid process of the radius

o Dorsal Tubercule of the radius (Lister’s Tubercule)

§ Prominent posteriorly on the dorsum of the hand

§ Tendon of extensor pollicis longus muscle runs on its medial side as it travels to the thumb laterally

o Inferior surface of the distal extremity of the radius is smooth and concave where it articulates with the carpal bones of the wrist (scaphoid, lunate)

o Articular disc of the radiocarpal joint extends from its inferior and medial surface

Carpals

- 16 bones bilateral, 8 unilaterally

- Small bones of the wist

- Collectively known as the carpus (L. wrist)

- 2 rows of 4 carpals

o Proximal row consists of:

§ Scaphoid laterally

§ Lunate

§ Triquetral

§ Pisiform medially

o Distal row consists of:

§ Trapezium laterally

§ Trapezoid

§ Capitate

§ Hamate medially

o Pnemonic

§ “Some Lovers Try Positions That They Can’t Handle”

§ Carpal bones from lateral to medial in the proximal row and lateral to medial in the distal row

Proximal Row of Carpals

Scaphoid (G. boat)

- Shaped like a peanut with a thin middle portion which is prone to fracture

- Receives its blood supply from distal to proximal

- Largest carpal of proximal row

- Attachment site of:

o Radial collateral ligament on its lateral surface

- Scaphoid tubercule

o Lies at the inferiolateral aspect of the anterior surface

o Contributes to lateral attachement site of the flexor retinaculum

o Attachment site of:

§ Abductor pollicus brevis muscle on its anterior surface

- Articulates with:

o Radius superiorly

o Lunate medially

o Trapezium inferiolaterally

o Trapezoid inferiormedially

Lunate (L. moon)

- Moon shaped bone

- Articulates with:

o Radius

o Scaphoid

o Triquetral

o Capitate

Triquetral

- the wist

- Articulates with:

o Lunate

o Hamate

Pisiform (L. pea)

- Small rounded bone, shaped like a pea

- Seasamoid bone of the flexor carpi ulnaris muscle

- Contributes to medial attachement site of the flexor retinaculum

- Articulates with:

o Triquetral

Proximal Row of Carpals

Trapezium

- Trapezium tubercule

o Lies at the …

o Attachment site of:

§ Abductor pollicus brevis muscle on its anterior surface

- Articulates with:

o Scaphoid

o Trapezoid

o Base of 1^st metacarpal at 1^st carpometacarpal joint

Trapezoid

- Articulates with:

o Scaphoid

o Trapezium

o Base of 2^nd metacarpal at 2^nd carpometacarpal joint

Capitate (L. head)

- Rounded bone

- Largest carpal

- Articulates with:

o Scaphoid

o Lunate

o Trapezoid

o Hamate

o Base of 3^rd metacarpal at 3^rd carpometacarpal joint

o Base of 4^th metacarpal at 4^th carpometacarpal joint

Hamate

- Hook of the Hamate

o Prominent process which projects anteriorly from inferiolateral aspect of anterior surface

o Attachment site of:

§ Contributes to medial attachement site of the flexor retinaculum

- Articulates with:

o Triquetral

o Lunate

o Base 5^th metacarpal at 5^th carpometacarpal joint

o Base 4^th metacarpal at 4^th carpometacarpal joint

Passage of ulnar nerve under hook of hamate

Metacarpals

- 5 long bones unilaterally, 10 bones bilateral

- Extend from carpals (wrist) to proximal phalanges (digits)

- Makes up the palm and dorsum of the hand with the carpals

- Numbered from lateral side

o 1^st metacarpal is the part of the thumb

o 2^nd metacarpal is the part of the index finger

o 3^rd metacarpal is the part of the middle finger

o 4^th metacarpal is the part of the ring finger

o 5^th metacarpal is the part of the little finger

- Base

o Proximal extremity

o Articulates with the carpals

- Shaft

o Slightly concave on medial and lateral borders where dorsal interossei muscles attach

- Head

o Distal extremity

o Small tubercule on dorsal surface is attachment of collateral ligaments and joint capsule

o Articulates with the proximal phalange of the same digit

1^st Metacarpal

- Forms base of the thumb within the palm

- Base articulates with the trapezium at the 1^st carpometacarpal joint

- Head articulates with 1^st proximal phalange at the 1^st metacarpophallangeal joint

- Medial surface is attachment of

o df

- Lateral surface is attachment of

o df

2^nd Metacarpal

- Forms base of the inex finger within the palm

- Base articulates with the trapezoid at the 2^nd carpometacarpal joint

- Head articulates with 2^nd proximal phalange at the 2^nd metacarpophallangeal joint

- Medial surface is attachment of

o df

- Lateral surface is attachment of

o df

3^rd Metacarpal

- Forms base of the middle finger within the palm

- Base articulates with the capitate at the 3^rd carpometacarpal joint

- Head articulates with 3^rd proximal phalange at the 3^rd metacarpophallangeal joint

- Medial surface is attachment of

o df

- Lateral surface is attachment of

o df

4^th Metacarpal

- Forms base of the ring finger within the palm

- Base articulates with the capitate and hamate at the 4^th carpometacarpal joint

- Head articulates with 4^th proximal phalange at the 4^th metacarpophallangeal joint

- Medial surface is attachment of

o df

- Lateral surface is attachment of

o df

5^th Metacarpal

- Forms base of the little finger within the palm

- Base articulates with the hamate at the 5^th carpometacarpal joint

- Head articulates with 5^th proximal phalange at the 5^th metacarpophallangeal joint

- Medial surface is attachment of

o df

- Lateral surface is attachment of

o df

Phallanges

- 14 long bones unilaterally, 24 bilateral

- Extend from metacarpals inferiorly to distal extent of upper limb

- Makes up the digits of the hand

- Numbered from lateral side

o 1^st phallanges are of the thumb

o 2^nd phallanges are of the index finger

o 3^rd phallanges are of the middle finger

o 4^th phallanges are of the ring finger

o 5^th phallanges are of the little finger

- Classified from proximal to distal

o Proximal phallanges are most proximal

o Middle phallanges lie between proximal and distal phallanges (except in the 1^st digit [thumb])

o Distal phallanges are most distal

- Base

o Proximal extremity

o Articulate proximally

- Shaft

o Slightly concave on medial and lateral borders

- Head

o Distal extremity

o Articulate distally

Proximal Phallanges

- 5 long bones unilaterally, 10 bilateral

- Extend from metacarpals distally to middle phallanges (distal phallanx of 1^st digit [thumb])

- Numbered from lateral to medial

o 1^st proximal phallanx of thumb

o 2^nd proximal phallanx of index finger

o 3^rd proximal phallanx of middle finger

o 4^th proximal phallanx of ring finger

o 5^th proximal phallanx of little finger

- Base

o Proximal extremity

o Articulate proximally with carpals at carpometacarpal joints

- Shaft

o Slightly concave on medial and lateral borders

- Head

o Distal extremity

o Articulate distally with middle phallanges (distal phallanx of 1^st digit [thumb])

1^st Proximal Phalanx

- 1 long bone unilaterally, 2 bilateral

- Base

o Attachment site of:

§ Flexor pollicis brevis muscle on its medial surface

§ Abductor pollicus brevis muscle on its anterior surface

§ Extensor pollicis brevis muscle on its lateral surface

o Articulates with 1^st metacarpal at the 1^st metacarpophalangeal joint

- Head

o Articulates with 1^st distal phalanx at 1^st interphallangeal joint

2^nd Proximal Phalanx

- 1 long bone unilaterally, 2 bilateral

- Base:

o Articulates with 2^nd metacarpal at the 2^nd metacarpophalangeal joint

- Head

o Articulates with 2^nd middle phalanx at the 2^nd proximal interphalangeal joint

3^rd Proximal Phalanx

- 1 long bone unilaterally, 2 bilateral

- Base:

o Articulates with 3^rd metacarpal at the 2^nd metacarpophalangeal joint

- Head

o Articulates with 3^rd middle phalanx at the 2^nd proximal interphalangeal joint

4^th Proximal Phalanx

- 1 long bone unilaterally, 2 bilateral

- Base:

o Articulates with 4^th metacarpal at the 2^nd metacarpophalangeal joint

- Head

o Articulates with 4^th middle phalanx at the 2^nd proximal interphalangeal joint

5^th Proximal Phalanx

- 1 long bone unilaterally, 2 bilateral

- Base:

o Articulates with 5^th metacarpal at the 2^nd metacarpophalangeal joint

- Head

o Articulates with 5^th middle phalanx at the 2^nd proximal interphalangeal joint

Middle Phalanges

- 4 long bones unilaterally, 8 bilateral

- Extend from proximal phalanges distally to distal phalanges (except for 1^st digit [thumb])

- Numbered from lateral to medial

o 2^nd middle phalanx of index finger

o 3^rd middle phalanx of middle finger

o 4^th middle phalanx of ring finger

o 5^th middle phalanx of little finger

- Base

o Proximal extremity

o Articulate proximally with proximal phalanges at proximal interphallangeal joints

- Shaft

o Slightly concave on medial and lateral borders

- Head

o Distal extremity

o Articulate distally with the distal phalanges

2^nd Middle Phalanx

- 1 long bone unilaterally, 2 bilateral

- Articulates with:

o 2^nd distal phalanx distally

o 2^nd proximal phalanx proximally

3^rd Middle Phalanx

- 1 long bone unilaterally, 2 bilateral

- Articulates with:

o 3^rd distal phalanx distally

o 3^rd proximal phalanx proximally

4^th Middle Phalanx

- 1 long bone unilaterally, 2 bilateral

- Articulates with:

o 4^th distal phalanx distally

o 4^th proximal phalanx proximally

5^th Middle Phalanx

- 1 long bone unilaterally, 2 bilateral

- Articulates with:

o 5^th distal phalanx distally

o 5^th proximal phalanx proximally

Distal Phallanges

- 5 long bones unilaterally, 10 bilateral

- Extend from middle phallanges (proximal phallanx of 1^st digit [thumb]) distally to tip of the fingers

- Numbered from lateral to medial

o 1^st distal phallanx of thumb

o 2^nd distal phallanx of index finger

o 3^rd distal phallanx of middle finger

o 4^th distal phallanx of ring finger

o 5^th distal phallanx of little finger

- Base

o Proximal extremity

o Articulate proximally with middle phallanges (proximal phallanx of 1^st digit [thumb]) at distal interphallangeal joints (interphallangeal joint of 1^st digit [thumb])

- Shaft

o Slightly concave on medial and lateral borders

- Head

o Distal extremity

1^st Distal Phallanx

- 1 long bone unilaterally, 2 bilateral

- Articulates with 1^st proximal phalanx proximally

- Base:

o Attachment site of:

§ Flexor pollicis longus muscle anteriorly

§ Extensor pollicis longus muscle posteriorly

2^nd Distal Phallanx

- 1 long bone unilaterally, 2 bilateral

- Articulates with 2^nd middle phalanx proximally

- Base:

o Attachment site of:

§ Flexor digitorum profundus muscle anteriorly

§ Extensor digitorum posteriorly

3^rd Distal Phallanx

- 1 long bone unilaterally, 2 bilateral

- Articulates with 3^rd middle phalanx proximally

- Base:

o Attachment site of:

§ Flexor digitorum profundus muscle anteriorly

§ Extensor digitorum posteriorly

4^th Distal Phallanx

- 1 long bone unilaterally, 2 bilateral

- Articulates with 4^th middle phalanx proximally

- Base:

o Attachment site of:

§ Flexor digitorum profundus muscle anteriorly

§ Extensor digitorum posteriorly

5^th Distal Phallanx

- 1 long bone unilaterally, 2 bilateral

- Articulates with 5^th middle phalanx proximally

- Base:

o Attachment site of:

§ Flexor digitorum profundus muscle anteriorly

§ Extensor digitorum posteriorly

Joints of the Upper Limb

<Upper Limb Anatomy>

- Sternoclavicular Joint

- Acromioclavicular Joint

- Glenohumeral Joint

- Elbow Joint

- Radioulnar Joints

- Proximal Radioulnar Joint

- Middle Radioulnar Joint

- Distal Radioulnar Joint

- Wrist Joint (Radiocarpal Joint)

- Intercarpal Joint

- Carpometacarpal Joint

- Carpometacarpal Joint of Thumb

- Metacarpophalangeal Joint

- Proximal Interphalangeal Joint

- Distal Interphalangeal Joint

Sternoclavicular Joint

Class: Synovial

Subclass: Double Plane or Saddle but acts more like ball and socket

Bony Contact: superiorlateral surface of manubrium with the sternal extremity of the clavicle

Movement: elevation, depression, protraction, retraction, circumduction of the clavicle on the manubrium

ROM: 0-60^o elevation of the clavicle

Stability: ligaments, articular disc

Vasculature: articular arteries of the internal thoracic artery and suprascapular artery

Innervation: articular nerves of the medial supraclavicular nerve and nerve to subclavius

Referred Pain:

- Movements of the scapula occur at this joint

- Amplifies movements of the upper limb

- This is the only bony attachment which joins the upper limb to the axial skeleton

- Fibrous joint capsule

- Articular disc

o Composed of fibrocartilage

o Divides the joint cavity in two compartments; medial and lateral

o Usually descends from the superior aspect of the joint capsule

o Prevents medial displacement of the clavicle

- Sternoclavicular ligaments

o Not clearly distinct from remainder of joint capsule

o Prevents excessive protraction and elevation of the clavicle

o Anterior sternoclavicular ligament

§ Thickened anterior portion of the joint capsule

o Posterior sternoclavicular ligament

§ Thickened posterior portion of the joint capsule

- Costoclavicular ligament

o Attaches to costal tubercule of the clavicle

o Passes inferiormedially to the costal cartilage of the 1^st rib

o Lies posterior to subclavius muscle and intercostal muscles

o Anchors the sternal extremity of the clavicle

- Interclavicular ligament

o Bridges the jugular notch of the sternum

o Attaches the joint capsules of the sternoclavicular joints bilaterally

o Is an extension of the joint capsule

o Limits lateral displacement of the clavicles

- Subclavius muscle

o Attaches to the subclavian groove of the clavicle

o Passes inferioromedially to the costal cartilage of the 1^st rib

o Acts as a contractile ligament to limit the superior displacement of the clavicle

Clinical: rarely dislocated

Acromioclavicular Joint (AC Joint)

Class: Synovial

Subclass: Plane/Gliding

Bony Contact: acromial extremity of clavicle with the acromium process of the scacpula

Movement: rotation and anterior and posterior movement of the acromium on the clavicle

Stability: coracoclavicular ligament

Vasculature: articular arteries of the suprascapular artery and thoracoacromial arteries

Innervation: articular nerves of the supraclavicular nerve, lateral pectoral nerve and axillary nerve,

articular nerves of the suprascapular nerve

Referred Pain:

- Joint capsule which is strongest anteriorly

- Articular surfaces are covered with fibrocartilage

- Coracoclavicular ligament

o Attaches to inferior surface of clavicle

o Strongest support for joint

o Innervated by the suprascapular nerve

o Composed of two separate ligaments

§ Conoid ligament

· Arises from the neck of the coracoid process

· Attaches to the conoid tubercule of the clavicle

· Lies at the posterior aspect of the clavicle, posterior to the trapezoid ligament

§ Trapezoid ligament

· Arises from the neck of the coracoid process

· Attaches to the trapezoid line of the clavicle

· Lies anterior to the conoid ligament

- Articular disc

o Incomplete

o Usually descends from the superior aspect of the joint capsule

Clinical: dislocations are not uncommon, “shoulder separation”

Glenohumeral Joint

Class: Synovial

Subclass: Ball and socket

Bony Contact: glenoid fossa of the scapula with the head of the humerus

Bursae: Subacromial bursa (subdeltoid bursa), subscapular bursa, subcoracoid bursa

Movement: flexion, extension, abduction, adduction, circumduction, rotation of humerus on scapula

Stability: rotator cuff (supraspinatus, infraspinatus, teres minor, subscapularis), coracoacromial arch

Vasculature: articular arteries of anterior & posterior humeral circumflex arteries & suprascapular artery

Innervation: articular nerves of suprascapular nerve, axillary nerve & lateral pectoral nerve

Referred Pain:

- Due to shallow joint space and freedom of movement it is a relatively unstable joint

- Coracoacromial ligament

o Attaches coracoid process of scapula to acromium of scapula

o Forms the coracoacromial arch

- Coracoacromial arch

o Formed from the coracoacromial ligament

o Coracoid process forms the anterioinferior edge

o Acromium process forms the posteriosuperior edge

o The supraspinatus muscle passes inferiorly

- Coracohumeral ligament

o Attaches to base of coracoid process

o Blends with superior portion of joint capsule

o Innervated by suprascapular nerve

- Glenohumeral ligament

o Thickening of the anterior portion of joint capsule

o Three components often difficult to distinguish which form a rough Z like shape

§ Superior glenohumeral ligament

§ Middle glenohumeral ligament

§ Inferior glenohumeral ligament

· Acts like a sling under the head of the humerus

- Transverse humeral ligament

o Joins the greater and lesser tubercules of the humerus

o Is continuous with the joint capsule

o Retains the long head of the biceps brachii within the bicipital groove

- Glenoid labrum (L. lip)

o Covers the glenoid fossa of the scapula

o Fibrocartilage

o Deepens the socket of the joint

o Continuous with the tendons of the long head of biceps brachii and the long head of triceps muscle

- Joint capsule

o Attaches to anatomical neck of the humerus

o Inferior portion displays increased laxity

- Rotator cuff muscles

o Serve to pull the humerus into the glenoid fossa of the scapula

o Tendons blend with the joint capsule

o Consist of:

§ Supraspinatus muscle

§ Infraspinatus muscle

§ Teres minor muscle

§ Subscapularis muscle

Clinical: rotator cuff tear, shoulder (humeral) dislocation

Subacromial Bursa (Subdeltoid Bursa)

- Lies between deltoid muscle, supraspinatus tendon and fibrous capsule of the shoulder joint

- Is not usually continuous with the synovial cavity of the shoulder joint

- Lies inferior to the acromium and to the coracoacromial ligament and superficial to the supraspinatus tendon

- Innervated by suprascapular nerve

Clinical: calcific supraspinatus tendonitis

Subscapular Bursa

- Continuous with the synovial cavity of the shoulder joint through the anterior portion of the joint capsule between the glenohumeral igaments

- Between tendon of subscapularis & neck of scapula

- Protects tendon of subscapularis as it passes inferior root of coracoid process & neck of scapula

Subcoracoid Bursa

Elbow Joint

Class: Synovial

Subclass: Hinge (Ginglymus)

Bony Contact:

- Trochlea of the humerus with the trochelar notch of the ulnar

- Capitulum of the humerus with the fovea of the head of the radius

Bursae: Subcutaneous olecranon bursa, subtendinous olecranon bursa, radioulnar bursa, bicipitoradial bursa

Movement: Flexion and extension of the forearm (ulna and radius) on the humerus

Stability: Trochlea notch, radial and ulnar collateral ligaments

Vasculature: Articular arteries of the collateral branches of the ulnar artery and radial artery

Innervation: Articular nerves of the musculocutaneous nerve and radial nerve

Referred Pain:

- Articular surfaces covered with hyaline cartilage

- Fibrous capsule completely encloses joint

- Sides are strengthened by collateral ligaments

o Radial collateral ligament

§ Triangular band

§ Apex at lateral epicondyle of humerus

§ Base blends with the anular ligament of the radius

o Ulnar collateral ligament

§ Triangular band

§ Anterior band

· Medial epicondyle of humerus

· Tubercule of the coronoid process of the ulna

§ Posterior band

· Medial epicondyle of humerus

· Medial edge of the olecranon process of the ulna

§ Oblique band connects the anterior and posterior bands

- Synovial capsule

o Continuous with the proximal radioulnar joint

o Sacciform recess emerges distal to anular ligament of radius

- Carrying angle (165^o)

Subcutaneous Olecranon Bursa

- lies in the subcutaneous connective tissue overlying the olecranon process of the ulna

Subtendinous Olecranon Bursa

- lies between the olecranon process of the ulna and the triceps brachi tendon proximal to its insertion on the olecranon

Radioulnar Bursa

- lie…

Bicipitoradial Bursa

- lie…

Radioulnar Joints

Proximal Radioulnar Joint

Class: Synovial

Subclass: Pivot (Trochoid)

Bony Contact: head of the radius with the radial notch of the ulna

Movement: pronation, supination of the wrist

Vasculature: articular branches of the radial and ulnar collateral arteries

Innervation: articular nerves of the musculocutaneous nerve, median nerve and radial nerve

Referred Pain:

- Annular ligament

o Strong “U” shaped band

o Hold the head of the radius in position as the forearm pronates and supinates

o Medially attaches to the anterior and posterior margins of the radial notch of the coronoid process of the ulna

o Laterally attaches to the neck of the radius

- Fibrous capsule continuous with the elbow joint

- Sacciform recess

o Distal continuation of the synovial joint of the elbow joint

Middle Radioulnar Joint

Class: Fibrous (Synarthrodial)

Bony Contact: ulnar interosseous border with the radial interosseous border

Movement: pronation and supination of radiocarpal joint

Vasculature: branches of the interosseos arteries

Innervation: anterior and posterior interosseous nerves

Referred Pain:

- Interosseous membrane links the ulnar and radial interosseous borders

o Provides attachment for the deep muscles of the forearm:

§ Asddsf???

o Deficiencies in membrane transmit….???

- Quadrate ligament

o Extends between the radial notch of the ulna and the medial surface of the neck of the radius

o Covers the synovial membrane of the distal radioulnar joint

- Oblique cord

o Passes from the ulnar tuberosity to the radius immediately distal to the radial tuberosity

- Reinforced by muscles:

o Pronator quadratus muscle

o Pronator teres muscle

o Supinator muscle

Distal Radioulnar Joint

Class: Synovial

Subclass: Pivot (Trochoid)

Bony Contact: ulna notch of the distal radius and the lateral surface of the head of the ulna

Movement: pronation, supination of the wrist

Vasculature: articular arteries of the anterior and posterior interosseous arteries

Innervation: articular nerves of the anterior and posterior interosseous nerves

Referred Pain:

- Joint capsule

- Articular disc binds distal ends of radius and ulna together

o Base attaches to medial edge of ulnar notch of radius

o Apex attaches to lateral side of base of ulnar styloid process

o Proximal part articulates with the distal aspect of the head of the ulna

o Seperats the distal radioulnar joint from the wrist joint

Wrist Joint (Radiocarpal Joint)

Class: Synovial

Subclass: Condyloid

Bony Contact: carpal articulating surface of the radius with the scaphoid and lunate carpal bones

Vasculature: articular arteries of the dorsal and palmar carpal arterial arches

Innervation: articular nerves of the anterior and posterior interior interosseos nerves, dorsal and deep branches of the ulnar nerve

Referred Pain:

- Ulna is separated from the wrist joint by articular disc of the distal radioulnar joint

Intercarpal Joint

Class: Synovial

Subclass: Plane/Gliding

Bony Contact: between the articulating surfaces of the carpal bones (scaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate, hamate)

Movement: flexion, extension, abduction, adduction of the hand, amplifies movements of the wrist

Vasculature: articular arteries of the palmar and dorsal carpal arches

Innervation: articular nerves of the anterior and posterior interossous nerves, dorsal and deep branches of the ulnar nerve

Referred Pain:

- Midcarpal joint is between the proximal and distal rows of carpals

o Flexion, extension, abduction, adduction of the hand

- Pisotriquetral joint is between the triquetral and pisiform

- Fibrous capsule helps unite the carpals

- Dorsal ligament

- Palmar ligament

- Ulnar ligament

- Radial ligament

Carpometacarpal Joint

Class: Synovial

Subclass: Plane/Gliding

Bony Contact: distal articulating surfaces of the distal carpals (trapezoid, trapezium, capitate, hamate) with the bases of the metacarpals

Movement:

Vasculature:

Innervation:

Referred Pain:

- Shares the joint capsule with the intercarpal joints

- Dorsal ligament

- Palmar ligament

- Interosseous ligament

Carpometacarpal Joint of the Thumb

Class: Synovial

Subclass: Saddle (Reciprocol Reception)

Bony Contact: articulating surface of the triguetral with the base of the 1^st metacarpal

Movement: angular movements in any plane, flexion, extension, abduction, adduction, opposition

Vasculature: articular arteries of the dorsal and palmar metacarpal arteries, dorsal carpal arterial arch and deep palmar arterial arch

Innervation:

Referred Pain:

- Has a separate joint cavity than the other carpometacarpal joints

Metacarpophallangeal Joint

Class: Synovial

Subclass: Condyloid

Bony Contact: head of the metacarpal with the base of the proximal phallange

Bursae:

Vasculature:

Innervation:

Referred Pain:

- ul joint

Proximal Interphallangeal Joint

Class: Synovial

Subclass: Hinge (Ginglymus)

Bony Contact: head of the proximal phalange with base of the middle phalange (distal phalange of thumb)

Bursae:

Vasculature:

Innervation:

Referred Pain:

- joint

- r

o ligament

§ band

Distal Interphallangeal Joint

Class: Synovial

Subclass: Hinge (Ginglymus)

Bony Contact: head of the meddle phalange with base of the distal phalange (not seen in thumb)

Bursae:

Vasculature:

Innervation:

Referred Pain:

- joint

- r

o ligament

§ band

Movements & ROM of the Upper Limb

<Upper Limb Anatomy>

- Descriptions

- Flexion

- Extension

- Abduction

- Adduction

- Circumduction

- External (Lateral) Rotation

- Internal (Medial) Rotation

- Pronation

- Supination

- Closed packed position

- Neutral position

- Capsular pattern

Pectoral Girdle

Movements of the Scapula

Elevation

Description:

Muscles: trapezius (upper), levator scapulae

Depression

Description:

Muscles: trapezius (lower), serratus anterior, pectoralis minor

Protrusion/Abduction

Description:

Muscles: serratus anterior

Retraction/Adduction

Description:

Muscles: trapezius, rhomboid major, rhomboid minor

Inferior Rotation

Description:

Muscles: rhomboid major, rhomboid minor, levator scapulae

Superior Rotation

Description:

Muscles: serratus anterior, trapezius

Movements of the Clavicle

Elevation

Description:

Muscles: trapezius (upper)

Depression

Description:

Muscles: subclavius

Movements of the Shoulder Joint

Joint Class:

Joint Subcalss:

Adduction

Description:

Muscles: pectoralis major, latissimus dorsi, deltoid (posterior head)

Abduction

Description:

Muscles: deltoid, supraspinatus

Flexion

Description:

Muscles: pectoralis major (clavicular head), deltoid (anterior head), coracobrachialis, biceps brachii

ROM: 0-180o

End Feel:

- Glenohumeral: abrupt and firm (ligamentous)

o Coracoacromial arch

- Shoulder Complex: abrupt and firm (ligamentous)

Extension

Description:

Muscles: latissimus dorsi, deltoid (posterior head), triceps brachii

ROM: 0-60o

End Feel:

- Glenohumeral: abrupt and firm (ligamentous)

- Shoulder Complex: abrupt and firm (ligamentous)

Medial Rotation (Internal Rotation)

Description:

Muscles: subscapularis, pectoralis major, deltoid (anterior head), latissimus dorsi, teres major

ROM: 0-180o

End Feel:

- Glenohumeral: abrupt and firm (ligamentous)

- Shoulder Complex: abrupt and firm (ligamentous)

Lateral Rotation (External Rotation)

Description:

Muscles: infraspinatus, teres minor, deltoid (posterior head)

ROM: 0-90o

End Feel:

- Glenohumeral: abrupt and firm (ligamentous)

- Shoulder Complex: abrupt and firm (ligamentous)

Circumduction

Scapulohumeral Rhythm

Movements of the Elbow Joint

Joint Class:

Joint Subcalss:

Flexion

Description:

Muscles:

ROM:

End Feel:

Extension

Description:

Muscles:

ROM:

End Feel:

Movements of the Proximal Radioulnar Joint

Joint Class:

Joint Subcalss:

Pronation

Description:

Muscles:

ROM:

End Feel:

Supination

Description:

Muscles:

ROM:

End Feel:

Movements of the Middle Radioulnar Joint

Joint Class:

Joint Subcalss:

Proximal Displacement of Radius

Description:

Muscles:

ROM:

End Feel:

Movements of the Distal Radioulnar Joint

Joint Class:

Joint Subcalss:

Pronation

Description:

Muscles:

ROM:

End Feel:

Supination

Description:

Muscles:

ROM:

End Feel:

Movements of the Radiocarpal and Midcarpal Joints

Joint Class:

Joint Subcalss:

Adduction

Description:

Muscles:

ROM:

End Feel:

Abduction

Description:

Muscles:

ROM:

End Feel:

Flexion

Description:

Muscles:

ROM:

End Feel:

Extension

Description:

Muscles:

ROM:

End Feel:

Movements of the Metacarpophallangeal Joints

Joint Class:

Joint Subcalss:

Adduction

Description:

Muscles:

ROM:

End Feel:

Abduction

Description:

Muscles:

ROM:

End Feel:

Flexion

Description:

Muscles:

ROM:

End Feel:

Extension

Description:

Muscles:

ROM:

End Feel:

Movements of the Interphallangeal Joints

Joint Class:

Joint Subcalss:

Flexion

Description:

Muscles:

ROM:

End Feel:

Extension

Description:

Muscles:

ROM:

End Feel:

Fingers

Movements

Axial (median) plane of the hand: passes through the centre of the 3^rd digit (middle finger).

Adduction: movement of the digits towards the axial plane of the hand

Abduction: movement of the digits away from the axial plane of the hand

Non Standard Digits

3^rd Digit (Middle Finger): as it lies in the axial plane of the hand it may be abducted either medially or laterally and adduction returns it to the axial plane.

1^st Digit (Thumb): as its neutral resting position is approximately at right angles to the other digits abduction moves the thumb anteriorly and adduction returns it posteriorly to the 2^nd digit (index finger).

Range of Motion

Muscles of the Upper Limb

<Upper Limb Anatomy>

- Pectoral Girdle

- Posterior Group

-Trapezius

-Rhomboid Major

-Rhomboid Minor

-Levator Scapulae

- Anterior Group

-Pectoralis Minor

-Subclavius

-Serratus Anterior

- Shoulder Joint

- Posterior Group

-Deltoid

-Supraspinatus

-Infraspinatus

-Teres Minor

-Teres Major

-Latissimus Dorsi

- Anterior Group

-Subscapularis

-Pectoralis Major

-Coracobrachialis

- Elbow Joint

- Biceps Brachii

- Brachialis

- Brachioradialis

- Triceps Brachii

- Aconeus

- Flexor Compartment of the Forearm

- Superficial Layer

-Pronator Teres

-Flexor Carpi Radialis

-Palmaris Longus

-Flexor Carpi Ulnaris

- Intermediate Layer

-Flexor Digitorum Superficialis

-Deep Layer

-Flexor Digitorum Profundus

-Flexor Pollcis Longus

- Deepest Layer

-Pronator Quadratus

- Extensor Compartment of the Forearm

- Superficial Layer

-Extensor Carpi Radialis Longus

-Extensor Carpi Radialis Brevis

-Extensor Digitorum

-Extensor Digiti Minimi

-Extensor Carpi Ulnaris

- Deep Layer

-Supinator

-Abductor Pollicis Longus

-Extensor Pollicis Brevis

-Extensor Pollis Longus

-Extensor Indicis

- Hand (Intrinsic Muscles)

- Thenar Muscles

-Flexor Pollicis Brevis

-Abductor Pollicis Brevis

-Oppenens Pollicis

-Adductor Pollicis

- Hypothenar Muscles

-Flexor Digiti Minimi

-Abductor Digiti Minimi

-Oppens Digiti Minimi

-Palmaris Brevis

- Short Muscles of the Hand

-Lumbricals

-Palmar Interossei

-Dorsal Interossei

Rhomboid Major

Origin: spinous processes of T2 to T5

Insertion: on the medial border of the scapula from inferior to scapula spine to the inferior angle

Action: retraction, upward rotation of scapula (as it lies inferior to central axis), fixes scapula to thoracic wall

Innervation: dorsal scapula nerve (C4, C5)

Blood Supply:

Features:

- Lies inferior to rhomboid minor muscle

- Lies immediately deep to trapezius muscle

- Functionally no different than rhomboid minor muscle

Rhomboid Minor

Origin: ligamentum nuchae, spinous process of C7 and T1

Insertion: medial border of scapula at the level of scapula spine

Action: retraction, upward rotation of scapula (as it lies inferior to central axis), fixes scapula to thoracic wall

Innervation: dorsal scapula nerve (C4, C5)

Blood Supply:

Features:

- Lies superior to rhomboid major muscle

- Lies immediately deep to trapezius muscle

- Functionally no different than rhomboid major muscle

Levator Scapulae

Origin: posterior tubercules of transverse processes of C1 to C4

Insertion: medial border of scapula superior to scapula spine

Action: elevation, downward rotation of scapula (as it lies superior to central axis), fixes scapula to thoracic wall

Innervation: dorsal scapula nerve (C5), C3 and C4 spinal nerves

Blood Supply:

Features:

- Fibers most inferiorly on scapula attach most superiorly on the cervical vertebrae creating some rotation of the muscle fibers

- Lies superior to rhomboid minor muscle in the same plane deep to trapezius

- Rotates scapula downward (inferiorly) whereas the rhomboids (major and minor) rotate upward (superiorly) as they attach to different side of the central axis of the scapula

Pectoralis Minor

Origin: 3rd to 5th ribs near costal cartilages

Insertion: medial border and superior surface of coracoid process of scapula

Action: stabiles scapula by drawing it inferior and anterior onto thoracic wall, depression, protraction

Innervation: medial pectoral nerve (C8, T1)

Blood Supply:

Acupoints: LU1, LU2, ST13 to ST17, SP18 to SP20, KI23 to KI27, PC1

Features:

- Most medial tendon to attach to coracoid process of scapula

- Lies deep to pectoralis major muscle

- Is pierced by medial pectoral nerve from posterior through anterior

- Lies anterior to subclavian vessels (subclavian artery, subclavian vein) and brachial plexus

Subcalvius

Origin: junction of 1st rib and its costal cartilage

Insertion: inferior surface of middle third of clavicle

Action: anchors (contractile ligament), depresses clavicle

Innervation: nerve to subclavius (C5, C6)

Blood Supply:

Acupoints:

Features:

- Lies deep to pectoralis major muscle

- Lies anterior to costoclavicular ligament

Serratus Anterior (L. saw like)

Origin: lateral surface of 1st to 8th ribs

Insertion: anterior surface of medial border of scapula

Action: protracts, upward rotates?? scapula, holds scapula to thoracic wall

Innervation: long thoracic nerve (C5, C6, C7)

Blood Supply:

Acupoints:

Features:

- Creates 2 pockets

(1) between its superficial surface and the deep surface of the subscapularis muscle through which many structures pass, this is accessed from the axilla

(2) between its deep surface and the superficial surface of the external intercostal muscles, this is accessed from the posteriomedial aspect of the scapula

Muscles of the Shoulder Joint

Anterior Group

Posterior Group

Posterior Group

Origin: scapula (all) and vertebrae (latissimus dorsi)

Insertion: humerus

Action: movement of the humerus

- Deltoid lies most superficial in same plane as trapezius

- Lattisums dorsi lies in the next plane and is deep to trapezius

- The remainder (supraspinatus, infraspinatus, teres minor and teres major) lie in the same plane immediately deep to deltoid.

o All of these except teres major attach to the posterior surfaces of the humerus consecutively inferior

Muscles of the Posterior Group of the Shoulder Joint.

(1) Deltoid

(2) Supraspinatus

(3) Infraspinatus

(4) Teres Minor

(5) Teres Major

(6) Lattisimus Dorsi

Deltoid (L. triangular)

- Divided into three heads:

o Anterior head

o Middle head

o Posterior head

Origin:

- Anterior head: lateral third of clavicle

- Middle head: acromium process of scapula

- Posterior head: spine of scapula

Insertion: deltoid tuberosity of humerus

Action: stabiles glenohumeral joint

- Anterior head: flexes and medially rotates humerus

- Middle head: abducts humerus

- Posterior head: extends and laterally rotates humerus

Innervation: axillary nerve (C5, C6)

Blood Supply:

Acupoints: SI9-SI10, TE14, LI14-LI15

Features:

- Thick muscle which covers the glenohumeral joint

Teres Minor

Origin: superior aspect of lateral border of scapula

Insertion: inferior facet of greater tubercule of humerus

Action: lateral rotation of humerus, stabilises humeral head in glenohumeral joint

Innervation: axillary nerve (C5, C6)

Blood Supply:

Acupoints:

Features:

- Elongated, triangular muscle

- Often inseperable from infraspinatus muscle superiorly

Teres Major

Origin: posterior surface of inferior angle of scapula

Insertion: medial lip of intertubercular groove of humerus

Action: adducts and medially rotates humerus

Innervation: lower subscapular nerve (C6, C7)

Blood Supply:

Acupoints:

Features:

Latisimus Dorsi (L. widest of posterior)

Origin: spinous processes of T7 to T12, thoracolumbar fascia (spinous processes of lumbar vertebrae), iliac crest, 9th or 10th to 12th ribs

Insertion: floor of interterbucular groove of humerus

Action: extends, adducts and medially rotates humerus, elevates trunk towards humerus with upper limb fixed

Innervation: thoracodorsal nerve (C6, C7, C8)

Blood Supply:

Acupoints:

Features:

- Large fan shaped muscle

Muscles of the Shoulder Joint

Anterior Group

Posterior Group

Anterior Group

Origin: scapula (all) and vertebrae (latissimus dorsi)

Insertion: humerus

Action: movement of the humerus

- Deltoid lies most superficial in same plane as trapezius

- Lattisums dorsi lies in the next plane and is deep to trapezius

- The remainder (supraspinatus, infraspinatus, teres minor and teres major) lie in the same plane immediately deep to deltoid.

o All of these except teres major attach to the posterior surfaces of the humerus consecutively inferior

Muscles of the Anterior Group of the Shoulder Joint.

(1) Deltoid

(2) Supraspinatus

(3) Infraspinatus

(4) Teres Minor

(5) Teres Major

(6) Lattisimus Dorsi

Subscapularis

Origin: subscapular fossa of scapula

Insertion: lesser tubercule of humerus

Action: adducts and medially rotates humerus, stabilises humeral head in glenohumeral joint

Innervation: upper subscapular nerve (C5, C6), lower subscapular nerve (C6, C7)

Blood Supply:

Acupoints:

Features:

- Thick triangular muscle

- Forms posterior wall of axilla

- Crosses anteriorly from scapula medial to humerus

Pectoralis Major

- Divided into two heads:

o Clavicular head

o Sternocostal head

Origin:

- Clavicular head: anterior surface of medial half of clavicle

- Sternocostal head: anterior surface of sternum, costal cartilages 1 to 6, aponeurosis of external oblique muscle

Insertion: two heads join common tendon and attach to the lateral lip of interbercular groove of humerus

Action: in combination adducts, medially rotates humerus

- Clavicular head: flexes humerus

- Sternocostal head: extends humerus

Innervation: lateral and medial pectoral nerves

- Clavicular head: lateral and medial pectoral nerves (C5, C6)

- Sternocostal head: lateral and medial pectoral nerves (C7, C8, T1)

Blood Supply:

Features:

- Forms bulk of anterior chest musculature

- Creates the anterior wall of the axillary fossa

- Receives the medial pectoral nerve from the pectoralis minor deeply

Trigger Points:

- May develop from stress overload or in conjunction with myocardial infarction

- Right sided trigger point (KI22) may be the source of cardiac arthymias

Acupoints: LU1, LU2, ST13, ST14, ST15, ST16, ST17, ST18, SP18, SP19, SP20, KI22, KI23, KI24, KI25, KI26, KI27, PC1, CV18

Coracobrachialis

Origin: tip of coracoid process of scapula, lateral to tendon of pectoralis minor and medial to short head of biceps brachii

Insertion: middle third of medial aspect of humerus, between insertions of triceps brachi and brachialis

Action: flexes and adducts humerus

Innervation: musculocutaneous nerve (C5, C6, C7)

Blood Supply:

Acupoints: LU2

Features:

- Elongated narrow muscle

- Is pierced from medial to lateral by the musculocutaneous nerve

- Lies between the pecotralis minor and short head of biceps brachii

Muscles of the Elbow Joint

Brachialis (L. arm)

Origin: distal half of anterior aspect of humerus, inferior to the deltoid tuberosity

Insertion: coronoid process and ulnar tuberosity of ulna

Action: elbow flexion

Innervation: musculocutaneous nerve (C5, C6, C7), may be contributed by radial nerve

Blood Supply:

Acupoints:

Features:

- Flattened fusiform muscle

- Shares some attachement with the lateral and medial intermuscular spetum, more extensively from medial

- Stongest flexor of forearm

- Lies posterior and deep to biceps brachii

- Covers the anterior aspect of the elbow joint (ulnohumeral joint and radiohumeral joint)

- If biceps brachii is lifted anteriorly the inferior surface of its belly can be seen to lie on top of brachialis

Brachioradialis

Origin: proximal 2/3rds of lateral supracondylar ridge of humerus

Insertion: lateral aspect of distal extremity of radius

Action: elbow flexion, assists pronation and supination of wrist

Innervation: radial nerve (C5, C6, C7)

Blood Supply:

Acupoints:

Features:

- Fusiform muscle

- Forms lateral boundary of cubital fossa

- Most superficial muscle of lateral forearm

- Is at a mechanical advantage at mid prone (neutral) position of forearm

- The radial nerve passes deep to brachioradialis until mid forearm where it emerges from its lateral border

Triceps Brachi (L. three heads of the arm)

- Divided into three heads:

o Long head

o Lateral head

o Medial head

Origin:

- Long head: infraglenoid tubercule of glenoid fossa of scapula, blends with superior portion of glenohumeral joint capsule

- Lateral head: posterior aspect of humerus between attachment of teres minor and radial groove, superior to radial groove

- Medial head: posterior aspect of humerus inferior to radial groove, extends posteriorly from attachment of teres major

Insertion: proximal aspect of olecranon process of ulna, deep fascia of forearm

Action: elbow extension

- Long head: steadies humeral head

Innervation: radial nerve (C6, C7, C8)

Blood Supply:

Acupoints:

Features:

- Large fusiform muscle

- Closely assoctiated with aconeus muscle

- Distal attachment originates from about midmuscle

- Long head passes posterior to teres major and anterior to teres minor separating the bellies creating the triangular space medially and quadrangular spaces laterally

- Main extensor of elbow

- Olecranon bursa

o Lies between distal attachment of triceps and olecranon process of ulna

Aconeus

Origin: lateral epicondyle of humerus

Insertion: lateral surface of olecranon process of ulna, superior portion of posterior aspect of ulna

Action: elbow extension (assists triceps brachii), stabilises elbow joint, abducts ulna during pronation, draws up synovial membrane of elbow joint during elbow extension

Innervation: radial nerve (C7, C8, T1)

Blood Supply:

Acupoints:

Features:

- Closely assoctiated with triceps brachii muscle

- Small triangular muscle

- Lies at posterior aspect of elbow on lateral side

- Someteimes considered part of medial head of triceps brachi muscle

Muscles of the Flexor (Anterior) Compartment of the Forearm

Divided into 4 layers

- Superficial

- Intermediate

- Deep

- Deepest

Lie on the medial aspect of the forearm

Innervation: median & ulnar nerve & their branches

Superficial Layer

- Contains 4 muscles, from lateral and proximal to medial are:

o Pronator Teres

o Flexor Carpi Radialis

o Palmaris Longus

o Flexor Carpi Ulnaris

- All have proximal attachments (origins) on the medial epicondyle of the humerus

Pronator Teres

Origin: medial epicondyle of humerus and coronoid process of ulna

Insertion: middle lateral aspect of humerus

Action: pronation of wrist, flexion of elbow

Innervation: median nerve (C6, C7)

Blood Supply:

Acupoints:

Features:

- Fusiform muscle

- Medial boundary of cubital fossa

Flexor Carpi Radialis (L. wrist flexor on radial side)

Origin: medial epicondyle of humerus

Insertion: base of 2^nd metacarpal

Action: flexion of wrist, abduction (radial deviation) of wrist

Innervation: median nerve (C6, C7)

Blood Supply:

Acupoints:

Features:

- Long fusiform muscle

- Located medial to pronator teres

- At midpoint of forearm becomes tendon

- Passes through canal in lateral part of flexor retinaculum?

- Passes through vertical groove of trapezium

- Lies medial to radial artery

Palmaris Longus (L. long muscle of the palm)

Origin: medial epicondyle of humerus

Insertion: distal half of flexor retinaculum and palmar aponeurosis

Action: flexion of wrist, tightens palmar aponeurosis

Innervation: median nerve (C7, C8)

Blood Supply:

Acupoints:

Features:

- Small thin fusiform muscle

- Absent in around 14% of people (usually on left)

- Often used as a replacement tendon for muscular injuries

- May have two bellies and/or two tendons

- Tendon passes superficial to flexor retinaculum

- Lies medial to median nerve at wrist

Flexor Carpi Ulnaris (L. wrist flexor on ulnar side)

- Divided into two heads:

o Humeral head

o Ulnar head

Origin:

- Humeral head: medial epicondyle of humerus

- Ulnar head: olecranon process of ulna and posterior border of ulna

Insertion: pisiform, hook of hamate and 5^th metacarpal

Action: flexion of wrist, adduction (ulnar deviation) of wrist, stabilies pisiform during action of hyothenar muscles

Innervation: ulnar nerve (C7, C8)

Blood Supply:

Acupoints:

Features:

- Most medial of superficial anterior forearm mucles

- Ulnar nerve passes between the fibrous arch between the humeral and ulnar heads of flexor carpi ulnaris proximally

- Lies medial to ulnar nerve and ulnar artery at wrist

Intermediate Layer

- Contains 1 muscle:

o Flexor digitorum superficialis

- Attachmes proximally (originates) from the medial epicondyle of the humerus and the radius and ulna

Flexor Digitorum Superficialis (L. superficial flexor of fingers)

- Divided into two heads:

o Humeroulnar head

o Radial head

Origin:

- Humeroulnar head: medial epicondyle of humerus, ulnar collateral ligament, coronoid process of ulna

- Radial head: superior ½ of anterior border of radius

Insertion: bodies of 2^nd to 5^th middle phalanges

Action: flexion of 2^nd to 5^th proximal interphalangeal joints, assists flexion of 2^nd to 5^th metacarpophalangeal joints

Innervation: median nerve (C7, C8, T1)

Blood Supply:

Acupoints:

Features:

- Largest muscle in anterior compartment of forearm

- Seperates the superficial from the deep muscles of the anterior compartment of the forearm

- Median nerve & ulnar artery pass deeply between humeroulnar and radial heads

- Gives rise to 4 tendons proximal to wrist which pass deep to flexor retinaculum within the carpal tunnel and are surrounded by a common flexor synovial sheath

- Tendons pass superficial to flexor digitorum profundus tendons in forearm

- Tendons to each digit are pierced by the tendon of flexor digitorum profundus as they split to pass either side of each digit

Clinical: Golfer’s elbow (medial humeral epicondylitis) is inflammation of the common flexor tendon on the medial epicondyle of the humerus

Deep Layer

- Contains 2 muscles, from medial to lateral are:

o Flexor digitorum profundus

o Flexor pollicis longus

- Do not attach to the humerus

- All have proximal attachments (origins) from the radius and/or ulna

Flexor Digitorum Profundus (L. large flexor of fingers)

Origin: proximal ¾ of medial and anterior aspects of ulna and interosseous membrane

Insertion: base of 2^nd to 5^th distal phalanges

Action: flexion of 2^nd to 5^th distal interphalangeal joints, flexion of 2^nd to 5^th proximal interphalangeal joints, flexion of wrist

Innervation:

- Medial half: ulnar nerve (C8, T1)

- Lateral half: median nerve (C8, T1)

Blood Supply:

Acupoints:

Features:

- Long thick muscle

- Medial to flexor pollicic longus

- Gives rise to 4 tendons proximal to wrist which pass deep to flexor retinaculum within the carpal tunnel

- Tendons pass deep to flexor digitorum superficialis tendons in forearm

- Passes through split in flexor digitorum superficialis tendons at proximal interphalangeal joints

- Tendon passing to 2^nd digit often is quite separate from the rest of the muscle belly

- Each tendon enters the fibrous sheath of its corresponding digit deep to flexor digitorum superficialis tendon

Flexor Pollcis Longus (L. long flexor of thumb)

Origin: anterior aspect of radius and interosseous membrane

Insertion: base of 1^st distal phalanx

Action: flexion of interphalangeal joint of thumb, assists in flexion of 1^st metacarpophalangeal joint, flexion of carpometacarpal joints of thumb, assists flexion of wrist

Innervation: anterior interosseous nerve from median nerve (C8, T1)

Blood Supply:

Acupoints:

Features:

- Long muscle

- Lateral to flexor pollicis longus

- Tendon passes deep to flexor retinaculum within the carpal tunnel

- Is covered by own synovial sheath lateral to common synovial sheath of flexor digitorum superficialis

Deepest Layer

- Contains 1 muscles:

o Pronator quadratus

- Does not attach to the humerus

Pronator Quadratus (L. four sided muscle of pronation)

Origin: distal ¼ of anterior aspect of ulna

Insertion: distal ¼ of anterior aspect of radius

Action: pronation of wrist, binds radius and ulna

Innervation: anterior interosseous nerve from median nerve (C8, T1)

Blood Supply:

Acupoints:

Features:

- Small quadrangular muscle

- Deepest muscle of flexor compartment of forearm

- Helps transmit forces from radius to ulna

Muscles of the Extensor (Posterior) Compartment of the Forearm

Divided into 2 layers

- Superficial

- Deep

Lie on the lateral aspect of the forearm

Innervation: radial nerve and its branches

Superficial Layer

- Contains 5 muscles, from anterolateral to postereomedial are:

o Extensor carpi radialis longus

o Extensor carpi radialis brevis

o Extensor digitorum

o Extensor digiti minimi

o Extensor carpi ulnaris

- All have proximal attachments (origins) on the latearl epicondyle or lateral supracondylar ridge of the humerus

Extensor Carpi Radialis Longus (L. long wrist extensor of the radial side)

Origin: lateral supracondylar ridge of humerus

Insertion: posterior aspect of base of 2^nd metacarpal

Action: extension of wrist, abduction (radial deviation) of wrist

Innervation: radial nerve (C6, C7)

Blood Supply:

Acupoints:

Features:

- Fusiform muscle

- Lies deep to brachioradialis muscle and is sometimes blended with

- Lies superficial distally to extensor carpi radialis brevis muscle

Extensor Carpi Radialis Brevis (L. short wrist extensor of the radial side)

Origin: lateral epicondyle of humerus

Insertion: posterior aspect of base of 3^rd metacarpal

Action: extension of wrist, abduction (radial deviation) of wrist

Innervation: deep radial nerve (C7, C8)

Blood Supply:

Acupoints:

Features:

- Lies deep distally to extensor carpi radialis longus muscle

Extensor Digitorum

Origin: lateral epicondyle of humerus

Insertion: extensor expansions of 2^nd to 5^th digits

Action: extension of 2^nd to 5^th proximal and distal interphalangeal joints, extension of 2^nd to 5^th metacarpophalangeal joints, extension of wrist

Innervation: posterior interosseous nerve from radial nerve (C7, C8)

Blood Supply:

Acupoints:

Features:

- Main extensor of the 2^nd to 4^th digits

- Most of the bulk of the posterior forearm

- Gives rise to 4 tendons proximal to wrist which pass deep to extensor retinaculum and are surrounded by a common extensor synovial sheath alongside the tendon of extensor digiti minimi

Extensor Digiti Minimi

Origin: lateral epicondyle of humerus

Insertion: extensor expansion of 5^th digit

Action: extension of 5^th interphalangeal joint, extension of 5^th metacarpophalangeal joint, extension of wrist

Innervation: posterior interosseous nerve from radial nerve (C7, C8)

Blood Supply:

Acupoints:

Features:

- Long thin fusiform muscle