The shoulder and arms Flashcards
what does the radial nerve innervate?
posterior arm muscles
what does the musculocutaneous nerve innervate?
anterior arm muscles
what does the axillary nerve innervate?
deltoid, teres minor
what does the thoracodorsal nerve innervate?
latissimus dorsi
what does the long thoracic nerve innervate?
serratus anterior
what do the lateral and medial pectoral nerves innervate
pectoralis major/minor
what do the suprascapualr and subscapular nerves innervate?
rotator cuff
what does the subclavian artery become?
subclavian –> axillary –> brachial artery
what are the branches of the brachial artery?
- circumflexhumoral arteries
- deep branch (profunda brachii artery)
what are the 3 branches off the axillary artery?
- superior thoracic artery
- thoraco-acromial, lateral thoracic artery
- subscapular, anterior and posterior humoral circumflex arteries
what is the venae comitantes of the brachial artery?
these are a pair of veins that closely accompany an artery in such a way hat pulsations of the artery aid venous return
what is the delto-pectoral groove?
triangle:
- clavicle superiorly
- deltoid laterally
- pectoralis major medially
what are the 3 articulations of the scapula?
glenohumoral joint
acromio-clavicular joint
scapulo-thoracic joint
describe the scapulo-thoracic joint
gliding phsiological joint with chest wall (via serratus anterior)
what are the spinal landmarks of the scapula?
superior angle - T2
medial end of scapula spine - T3
inferior angle - T7
describe the ossification of the clavicle
- first long bone to ossify (5th week)
- intamembranous ossificiation not endochondral
describe the 2 ends of the clavicle
flat lateral end at acromion of scapula
circular sternal end at sternum/1st CC
what can be found on the distal end of the humerus?
laterally = capitulum medially = trochlea
what can be found on the posterior aspect of the humerus?
olecranon
what are the points of articulations on the humerus?
glenoid cavity of scapula
capitulum (radius)
trochlea (ulnar)
describe the axillary nerve in relation to the humerus
winds around surgical neck of humerus
when can the axillary nerve be damaged?
in shoulder dislocation
describe the radial nerve in relation to humerus
runs in radial groove
what can damage the radial nerve?
humoral shaft fractures
describe the relation of the ulnar nerve to the humerus?
runs posterior to medial epicondyle
what can damage the ulnar nerve?
dislocations of elbow joint
describe the relation of the median nerve to the humerus
runs anterior to distal humerus
what can damage the median nerve?
supracondylar fractures of humerus
dislocations of elbow joint
what does the SCM do? Innervation?
turn head left/right against resistance
CN 11, C3, C4
what does the trapezius do? innervation?
raise both shoulders against resistance
CN 11, C3, C4
what does the pec major do? innervation?
adduct and abduct arm against resistance
lateral/medial pectoral nerve (C5-T1)
what does the serratus anterior do? innervation?
both arms outstretched with arms against wall and press firm
long thoracic nerve, C5, C6
what does the teres major do? innervation?
adduct arm against resistance
lower subscapular nerve, C5, C6
what does the latissimus dorsi do? innervation?
abduct arm to 90 degreees
adduct against resistance
thoraco-dorsal nerve, C6, C7, C8
what does the deltoid do? innervation?
abduct upper arm against resistance
axillary nerve, C5, C6
what movements does the scapulo-thoracic joint allow?
- elevation
- depression
- protraction
- retraction
- rotation up
- rotation down
which muscles are responsible for elevation at the scapulo-thoracic joint?
- superior trapezius
- levator scapulae
- rhomboids
which muscles are responsible for depression at the scapulo-thoracic joint?
- inferior trapezius
- pectoralis minor
- serratus anterior
which muscles are responsible for protraction at the scapulo-thoracic joint?
- pec minor
- serratus anterior
which muscles are responsible for retraction at the scapulo-thoracic joint?
- rhomboids
- middle trapezius
- latissimus dorsi
which muscles are responsible for rotation up at the scapulo-thoracic joint?
- superior trapezius
- inferior trapezius
- serratus anterior
what movements does the shoulder joint allow?
- flexion
- extension
- abduction
- adduction
- internal rotation
- external rotation
which muscles are responsible for flexion at the shoulder joint?
- pec major
- deltoid
which muscles are responsible for extension at the shoulder joint?
deltoid
which muscles are responsible for abduction at the shoulder joint?
supraspinatus (inital 15 degrees)
deltoid after
which muscles are responsible for adduction at the shoulder joint?
pec major
latissimus dorsi
which muscles are responsible for internal rotation at the shoulder joint?
subscapularis
which muscles are responsible for external rotation at the shoulder joint?
infraspinatus
which movements does the elbow joint allow?
- flexion
- extension
which muscles are responsible for flexion at the elbow joint?
- biceps
- brachialis
- brachioradialis
which muscles are responsible for extension at the elbow joint?
triceps
where can you palpate the trunks of the brachial plexus?
supraclavicular fossa
where can you palpate the median nerve?
cubital fossa
medial to brachial artery
where can you palpate the radial nerve?
cubital fossa
lateral to biceps tendon
where can you palpate the ulnar nerve?
elbow
medial epicondyle
where can you palpate the median nerve?
wrist
palmaris longus, FCR
where can you palpate the ulnar nerve?
wrist
medial to ulnar pulse
which nerves supply the anterior and posterior compartments of the arm?
radial nerve - post
median/ulnar - ant
what nerve innervates the flexor-pronator compartment?
posterior interosseous nerve
what nerves innervates the extensor-supinator compartment?
- posterior interosseous nerve
- radial artery
- median nerve
- ulnar nerve
what is compartment syndrome?
inc. in pressure in facial compartment due to inflammatory response that can impinge vessels and nerves
what is healing in compartment syndrome?
by fibrosis and contracture
what are the signs and symptoms?
pain, pallor, cold, absent pulse and limited movement
what is the treatment of compartment syndrome?
fasciotomy
what is the cause of Erb’s palsy?
damage to C5, C6 during birth or motorcycle falls (abduction of head and neck)
what are the muscles affected in Erb’s palsy?
supra/infraspinatus deltoid biceps brachialis brachioradialis supinator wrist extensors
what is the presentation of Erb’s palsy?
arm adducted, medially rotated, pronated forearm with flexed wrist
(Waiter’s tip position)
what are the causes of Klumpke’s palsy?
damage to C8, t1 when arm pulled superior
birth trauma, breaking a fall by hanging on branch, violent abduction
how do you locate the site of the lesion in Klumpke’s palsy?
test for elevation of scapula. if nerves to Levator scapulae and rhomboids are inracr, lesion is distal = GOOD prognosis
if pt has Horner’s syndrome (T1 symp damage), BAD. sympathetic component is proximal
what are the muscles affected in Klumpke’s palsy?
FC ulnaris
FD profundus
lumbricals
all interossei
what are the 3 types of Klumpke’s palsy?
- ulnar claw hand
- median nerve claw hand (Hand of Benediction)
- true claw hand
describe ulnar claw hand
- clawing of 4th and 5th fingers at rest
- thumb inability to adduct
- difficulty in making a fist (MCP joints hyperextended, unopposed action of extensor digitorum)
- sensory loss to ulnar side of forearm and hand
describe median nerve claw hand
when trying to make a fist, 2nd and 3rd fingers fail to flex completely, thumb unable to oppose
what muscles are involved in median nerve claw hand?
FC profundus (radial) lumbricals (radial)
describe why people with median nerve claw hand struggle to make a fist
flexion of 2nd and 3rd digits incomplete at distal interphalangeal joints
MCP joints hyperextended due to unopposed action of extensor digitorum
thumb can’t oppose due to paralysis of opponens pollicis, FP brevis
describe the fingers in the true claw hand
clawing present in all 4 fingers
thumb assuming abducted position
what nerve damage is seen in true claw hand?
ulnar and median nerve damage
what do the lumbrcials and interossei do?
cause flexion of MCP joints
what do the extensor digitorum tendons cause?
extension of IP joints
what would be seen with a radial nerve lesion?
- UPPER ARM: triceps affected –> impaired extension
- FOREARM: supinator and wrist extensors –> wrist drop
- CUTANEOUS: dorsum of hand and lateral digits
what would be seen with a musculocutaneous nerve lesion?
- ELBOW JOINT: flexors affected
- CUTANEOUS: lateral side of forearm up to wrist
what would be seen with a median nerve lesion?
FOREARM: wrist flexors –> wrist adducted
FOREARM: pronators affected –> forearm supine
DIGITS: flexion –> hand of benediction
THENAR muscles: paralysed
CUTANEOUS: sensory loss
what would be seen with a ulnar nerve lesion?
FOREARM: carpi ulnaris, medial FD profundus paralysed
SMALL MUSCLES OF HAND: paralysed –> claw hand
CUTANEOUS: medial half palm and arm/forearm
describe the generic pathway in reflex testing
tendon is tapped by hammer
muscle spindle stretches
stimulation to motor neuron
conveys impulse round and back to muscle to flex in response
what nerve are you testing in the biceps reflex response?
musculocutaneous nerve (C5, C6)
what nerve are you testing with the tricpes and brachioradialis supinator response?
radial nerve
what is frozen shoulder? Cause?
- pain and stiffness in shoulder, esp during external rotation
- unknown cause, may be autoimmune
what is the treatment of frozen shoulder?
- pain (anti-inflammatories, systemic steroids)
- stiffness (physiotherapy)
- recovery (physiotherapy and arthroscopic surgery)
what is shoulder impingement syndrome?
pain and weakness when abducting arm
what are the causes of shoulder impingement syndrome?
- bone spurs under acromion at top of sub-acromial space (catches tendon)
- swelling or thickening of rotator cuff tendon
- bursitis
- Ca deposits in rotator cuff tendon
what is tennis elbow?
injury to insertion of extensor tendons on lateral epicondyle of humerus
what is the cause of tennis elbow?
sharp flexion of wrist whilst extensors are contracted
backhand of tennis ball
what is the treatment of tennis elbow?
rest and steroids
what is golfer’s elbow?
injury to insertion of flexor attachment on medial epicondyle of humerus
what is the cause of golfer’s elbow?
sharp flexion of elbow
golfer hitting ground instead of ball
what is the treatment of golfer’s elbow?
rest and steroids
what is mallet finger?
avulsion of extensor digitorum longus tendon at base of distal phalanx
what is Poacher’s thumb?
damage to medial collateral ligament of first MCP joint by violent abduction
what causes trigger finger?
flexor profundus longus tendon causes friction to tendon sheath
gets swelling of tendon which irritates sheath and narrows sheath
when finger is flexed, it gets stuck in flexed position
what causes Colle’s fracture?
falling on outstretched hand leading to fracture of distal radius and ulnar styloid
what would you see with Colle’s fracture?
dorsal displacement and dorsal angulation on x-ray
proximal impaction and radial deviation
what is osteoarthritis?
degenerative changes in cartilage affecting articular cartilage and periarticular bone
what causes the pain, stiffness and discomfort?
narrowing of joint space in inter-phalangeal joint
what is rheumatoid arthritis?
chronic inflammatory condition resulting in synovitis of peripheral joints
