Upper Limb Regional and Functional Anatomy

Week 2 Wednesday, Week 3 Monday girll you do not have to know individual origins and insertions do not study those (only need to know attachment sites which are common to multiple muscles)

latissimus dorsi

Origins: T7 to L5 spinous processes + iliac crest to intertubercular groove of humerus

Prime Actions:

• Extends

• ADDucts arm

• medially rotates arm

(important for swimming and climbing)

levator scapulae

Attachments: Supero-medial border of scapula to transverse processes of C1-C4 vertebrae

Prime action: Elevates scapula & downward rotation

rhomboid major

Attachments: C7-T5 spinous processes of vertebrae to medial border of scapula

(same as rhomboid minor)

Prime Actions:

• Retracts scapula

• downward rotation

• (same as rhomboid minor)

pectoralis major

Attachments: Medial clavicle and sternum to intertubercular sulcus of humerus

Prime actions:

• ADDuction (+horizontal & diagonal)

• Medial Rotation of humerus

• Flexion to 60 degrees

rhomboid minor

Attachments: C7-T5 spinous processes of vertebrae to medial border of scapula

(same as rhomboid major)

Prime Actions:

• Retracts scapula (opposite of hugging)

• downward rotation

• (same as rhomboid major)

pectoralis minor

Attachments: Ribs 3-5 to Coracoid process of scapula

Prime Actions:

• Stabilisation

• Scapula protraction (hugging motion)

• Scapula depression

• Scapula downward rotation

• (same as serratus anterior)

trapezius

Origin:

• Nuchal line (skull)

• External occipital protuberance (skull)

• C7-T12 spinous processes

Insertion: spine of scapula + lateral third of clavicle + acromion

Prime Actions:

• Elevates & depress scapula

• retracts

• upward rotation of scapula

Origin:

• Nuchal line (skull)

• External occipital protuberance (skull)

• C7-T12 spinous processes

Insertion: spine of scapula + lateral third of clavicle + acromion

Prime Actions:

• Elevates & depress scapula

• retracts

• upward rotation of scapula

serratus anterior

Attachments: Ribs 1-8 to medial border of scapula

Prime Actions:

• scapula protraction (hugging motion)

• scapula depression

• scapula upward rotation

deltoid

teres major

muscles responsible for scapula elevation

• Trapezius

• Levator Scapulae

• Rhomboid major and minor

muscles responsible for scapula depression

• Trapezius

• Pectoralis minor

muscles responsible for scapula retraction

• Trapezius

• Rhomboid major and minor

muscles responsible for scapula protraction

• Serratus anterior

• Pectoralis minor

muscles responsible for scapula downward rotation

• Rhomboid major and minor

• Levator scapulae

• Pectoralis minor

muscles responsible for scapula upward rotation

• Trapezius

• Serratus anterior

deltoid origin and insertion

Origins:

• lateral 1/3 clavicle

• acromion

• scapular spine

insertion:

• deltoid tuberosity

deltoid actions

shoulder abduction (flexion & extension)

deltoid nerve supply

axillary nerve (C5)

dynamic ligaments

• required to stabilise the shoulder (restrain it to prevent a shoulder joint subluxing when deltoid muscle contracts)

• muscles of the rotator cuff perform this role

supraspinatus

supraspinatus origins and insertions

origin:

• medial ¾ supraspinous fossa and spine

insertion:

• smooth facet on upper part of GT

supraspinatus nerve supply

suprascapular nerve (C5)

supraspinatus actions

• stabilises head of humerus

• initiates abduction

infraspinatus (posterior)

infraspinatus origin and insertion

origin: infraspinous fossa

insertion: greater tuberosity (central facet)

infraspinatus nerve supply

suprascapular nerve (C5)

infraspinatus action

• stabilises head of humerus

• GH external rotation

teres minor

teres minor origin and insertion

origin: lateral scapular border

insertion: greater tuberosity (lowest facet)

teres minor nerve supply

axillary nerve (C5)

teres minor action

• stabilises head of humerus

• external/lateral rotation

• (weak adduction)

subscapularis (anterior)

subscapularis origin and insertion

origin: scapula costal surface

insertion: lesser tuberosity

subscapularis nerve supply

upper and lower subscapular nerves (C6, C7)

subscapularis action

• stabilises head of humerus

• internal/medial rotation

four muscles (rotator cuff muscles) sitting on the head of the humerus and function

function: stability and motility of the should (GH) joint during abduction and rotation

muscles:

S: Supraspinatus

I: Infraspinatus

T: Teres Minor

S: Subscapularis

teres major

teres major origin and insertion

origin: lateral, inferior scapular angle

insertion: medial bicipital groove (below subscapularis)

teres major nerve supply

lower subscapular nerve

teres major action

• stabilises upper humerus (against action of deltoid)

• adductor

• medial humerus rotation

humerus posterior compartment

• triceps brachii

• anconeus

humerus anterior compartment

• biceps brachii

• coracobrachialis

• brachialis

coracobrachialis

coracobrachialis action

• shoulder flexion

• shoulder adduction

coracobrachialis origin and insertion

origin:

• humerus (anterior shaft)

insertion:

• coracoid process

brachialis

brachialis origin and insertion

origin:

• humerus (anterior shaft)

insertions:

• coronoid process

• ulna tuberosity

brachialis action

elbow flexion

biceps brachii

biceps brachii action

• elbow flexion

• elbow supination

• GH flexion (weak)

biceps brachii origin and insertion

origin:

• short: coracoid process

• long: supraglenoid tub

insertion:

• radial tuberosity

slap lesion

• Muscle involved: long head of the biceps tendon (primarily)

• Mechanism: A tear in the labrum cartilage at the point where the biceps tendon attaches. 

popeye’s sign

a bulge in the upper arm that occurs when the biceps tendon ruptures

triceps brachii

triceps brachii origin and insertion

origin:

• long: infraglenoid tubercle

• lateral: humerus (posterior shaft)

• medial: posterior humerus (inferior to radial groove)

insertion:

• olecranon of ulna

triceps brachii action

• chief extensor of elbow

• GH extension (long head)

anconeus

(posterior humerus + posterior superficial antebrachium)

anconeus origin and insertion

origin:

• lateral epicondyle of humerus

insertion:

• lateral olecranon

• posterior ulna shaft

anconeus action

assists triceps in elbow extension

annular ligament

• stabiliser of the proximal radioulnar joint

• allows for smooth and unrestricted rotation of the forearm during pronation and supination

elbow flexion muscles

• brachialis (slow)

• biceps brachii (slow)

• brachioradialis (fast)

elbow extension muscles

• triceps brachii

• anconeus (minor assistance)

arm supination muscles

• supinator

• biceps brachii (assists only when movements are fast/forceful)

(sup high five)

arm pronation muscles

• pronator quadratus

• pronator teres

  

(i’m kind of a pro)

anterior forearm/antebrachium muscles

• flexors of the wrist and hand

• three layers (deep, middle, superficial)

• superficial: common attachment to medial epicondyle

anterior antebrachium signs of weakness

when lifting heavy objects, patient is not able to sufficiently stabilize wrist with supinated forearm; tilting dorsally

deep anterior antebrachium signs of weakness

When lifting heavy objects, the affected patient is not able to sufficiently stabilize the wrist with supinated forearm; thus wrist tilts in a dorsal direction

• supinator

• flexor digitorum profundus

• flexor pollicis longus

• pronator quadratus

• (sffp - median nerve)

golfer’s elbow

epicondylitis medialis

inflammation of tendons attached to muscles of the anterior antebrachium

posterior forearm muscles

• extensors of the wrist and hand

• two layers (deep and superficial)

• superficial: common attachment to lateral epicondyle

flexor carpi radialis (anterior superficial antebrachium)

→pointer finger

flexes and abducts wrist

flexor carpi ulnaris (anterior superficial antebrachium)

→ring finger (professional frogs partake (in) fun)

pronator teres (anterior superficial antebrachium)

→thumb (professional frogs partake (in) fun)

palmaris longus (anterior superficial antebrachium)

→middle finger (professional frogs partake (in) fun)

flexor digitorum superficialis (anterior intermediate antebrachium)

insertion on the middle phalanges

flexor digitorum superficialis actions

primary flexor of PIPJ (proximal interphalangeal joints) and secondary flexor of MCPJ (metacarpophalangeal joints)

carpal tunnel

• The carpal tunnel is a narrow passageway in the wrist that's made up of the carpal bones and the transverse carpal ligament. 

• The median nerve and nine tendons run through the carpal tunnel

• Carpal tunnel syndrome (CTS) is a condition that occurs when the median nerve in the wrist is compressed → shooting pain

  • chronic = thenar atrophy (muscles in the base of the thumb to waste away)

flexor pollicis longus (anterior deep antebrachium)

flexor digitorum profundus (anterior deep antebrachium (sffp))

pronator quadratus (anterior deep antebrachium)

supinator (anterior deep antebrachium)

‘outcropping muscles’/muscles making up the ‘anatomical snuffbox’

think ‘brevis sandwich’:

• abductor pollicis longus

• extensor pollicis brevis

• extensor pollicis longus

• extensor indicis (sometimes excluded)

(posterior deep antebrachium)

extensor indicis (posterior deep antebrachium)

extensor pollicis longus (posterior deep antebrachium)

extensor pollicis brevis (posterior deep antebrachium)

abductor pollicis longus (posterior deep antebrachium)

abductor pollicis longus (posterior deep antebrachium) (bottom of the thumb)

(part of anatomical snuffbox)

anatomical snuffbox

branch of the radial nerve + radial comes through this region

scaphoid fractures (common) can lead to laceration of artery and damage to nerve

extensor pollicis brevis (posterior deep antebrachium) (attaches to the thumb, shorter than longus)

(part of anatomical snuffbox)

extensor pollicis longus (posterior deep antebrachium)

scaphoid

posterior superficial antebrachium muscles

• anconeus

• extensor carpi ulnaris

• extensor digiti minimi

• extensor digitorum

arise from the lateral humeral epicondyle, via the common extensor tendon

extensor digiti minimi (insertion: 5th digit) (posterior superficial antebrachium)

extensor digitorum (insertion: medial four digits) (posterior superficial antebrachium)

extensor carpi ulnaris (insertion: base of 5th metacarpal) (posterior superficial antebrachium)

tennis elbow

epicondylitis lateralis: inflammation of lateral epicondyle

• attachment point for the four posterior superficial antebrachial muscles (extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, and anconeus)

  + extensor carpi radialis brevis

pain on extension of the wrist

mobile wad of three

three muscles forming the lateral bulge at the elbow:

• brachioradialis

  • (flexes elbow)

• extensor carpi radialis longus

  • (base 3rd metacarpal)

• extensor carpi radialis brevis

  • (base 2nd metacarpal)

nerve supply: radial nerve

posterior antebrachium

brachioradialis (“beer drinking muscle”)

extensor carpi radialis longus