MSK Flashcards
What are the causes of Klumpke palsy? What nerves, muscles, motor and sensory functions are affected and what are the signs?
Excessive abduction of arm - falling from a tree and catching a branch/pulling baby out by arm T1: ulna and median nerve Small muscles in hand don't work Medial side of arm loses sensation Clawed hand
What are the causes of Erb’s palsy? What nerves, muscles, motor and sensory functions are affected and what are the signs?
Difficult birth/blow to shoulder
C5-C6 root: musculocutaneous, axillary, suprascapular, nerve to subclavius
Supraspinatus, infraspinatus, subclavius, biceps brachii, brachialis, coracobrachialis, deltoid, teres minor
Abduction and flexion of shoulder, lateral rotation of arm and supination affected
Lateral side of arm loss of sensation
Waiters tip: medially rotated and pronated
What are the likely causes of damage to the axillary nerve? What muscles, motor and sensory functions are affected and what are the signs?
Anterior dislocation of humerus at glenohumeral joint, fracture of humerus at surgical neck
Deltoid, teres minor - can’t abduct shoulder
Regimental badge area
Deltoid atrophy so deltoid tuberosity can be palpated
What are the likely causes of damage to the radial nerve?
Damaged in axilla - dislocate humerus at glenohumeral joint, fracture proximal humerus or excess pressure on axilla
Damaged in radial groove - mid shaft fracture
Deep branch - radial head fracture or posterior radial dislocation at elbow
Superficial - stabbing or lacerations
What are the motor and sensory functions affected if the radial nerve was damaged in the axilla, radial groove, deep branch or superficial?
Can’t extend at elbow and wrist drop / back or arm and some of hand
Wrist drop / hand
No wrist drop as extensor carpi radialis works / none
None / hand
What is the likely cause of damage to the musculocutaneous nerve? What muscles, motor and sensory functions are affected and what are the signs?
Stabbed in axilla
Coracobrachialis, brachialis and biceps brachii so weakened flexion at shoulder (pec major) and elbow (brachioradialis) and weakened supination (supinator)
Lateral forearm
What are the likely cause of damage to the median nerve? What muscles, motor and sensory functions are affected and what are the signs?
Suprancondylar fracture of humerus
Flexors and pronators paralysed (except FCU and FDP) so constant supination, weak flexion with adduction, no thumb flexion and can’t flex and MCP joint
Hand
Atrophy of thenar muscles and hand of benediction when attempting to make fist
If caused at wrist (lacerations) only affects thenar/lumbricals
What is the likely cause of damage to the ulnar nerve? What muscles, motor and sensory functions are affected and what are the signs?
Medial epicondyle fracture
Flexor carpi ulnaris and medial half of flexor digitorum profundus so wrist flexion is accompanied by abduction. Interossei so no ab/adduction of fingers. Lateral lumbricals (little and ring finger)
Medial half of hand
Can’t grip paper
If at wrist (lacerations) just interossei and lumbricals affected and only palmar, medial one and a half fingers lose sensation.
Prolonged get ulnar claw
What innervates the trapezius and what is its function?
Accessory nerve
Upper - elevate and rotate scapula during abduction
Middle - retract scapula
Lower - pull scapula inferiorly
What innervates the latissimus dorsi and what is its function?
Thoracodorsal nerve
Extension and adduction of arm at shoulder. Medially rotate arm
What innervates the levator scapulae and what is its function?
Dorsal scapula nerve
Elevate scapula and rotate to tilt glenohumeral joint inferiorly
What innervates the rhomboids (major/minor) and what is its function?
Dorsal scapula nerve
Retract scapula and rotate it so tilt glenohumeral joint inferiorly
What innervates the deltoid and what is its function?
Axillary nerve
Anterior - flex arm at shoulder
Posterior - extend arm at shoulder
Middle - abduct arm after 15 degrees
What innervates the teres major and what is its function?
Lower subscapular nerve
Adduction of arm at shoulder and medially rotate
What innervates the Supraspinatus and what is its function?
Suprascapular nerve
First 15 degrees of abduction
What innervates the infraspinatus and what is its function?
Supra scapular nerve
Lateral rotation
What innervates the subscapularis and what is its function?
Upper and lower subscapular nerves
Medial rotation
What innervates the teres minor and what is its function?
Axillary nerve
Laterally rotate arm
Explain rotator cuff tendonitis
Sub acromial bursa supraspinatus tendon degenerate and causes pain in middle of abduction “painful arc”
Irritating the coraco-acromial arch inflames rotator cuffs
What innervates pectoralis major and what is its function?
Medial and lateral pectoral nerve
Adduct, medially rotate and flex arm at shoulder
What innervates pectoralis minor and what is its function?
Medial pectoral nerve
Depress shoulder
What innervates serratus anterior and what is its function?
Long thoracic nerve
Rotate scapula to allow abduction over 90 degrees. Hold scapula against ribcage
Explain the winging of scapula
Scapula protrudes out of back due to trauma or repetitive movements of the shoulder or inflammation damaging the long thoracic nerve
What is a Colles’ fracture?
Fall on outstretched hand
Fracture distal radius and the distal fragment is displaced posteriorly (dinner fork)
What is a Smith’s fracture?
Fall on back of hand. Distal segment to fracture is displaced anteriorly
How can the radial head be fractured?
Forced into capitulum and shatters
What is a Monteggia’s fracture?
Blow behind the ulna causing the ulna to fracture and radial head to dislocate at elbow
What is a Galeazzi’s fracture?
Radius fractures and ulnar head dislocates at the distal radial ulnar joint
How can the ulna fracture and what happens to the fragments?
Blow to ulna. Proximal section pulled posteriorly
Fall on flexed elbow. Triceps displace proximal posteriorly
What is a Boxer’s fracture
Fracture of the 5th metacarpal neck usually from punching something
Distal portion displaced posteriorly
What is a Bennett’s fracture?
Fracture of first metacarpal base caused by hyperabduction of thumb
What innervates the gastrocnemius and what is its function?
Tibial nerve
Plantarflexion of foot and flex knee
What innervates the plantaris and what is its function?
Tibial nerve
Plantarflex ankle and flex knee. Not vital
What innervates the soleus and what is its function?
Tibial nerve
Plantarflexes ankle
What innervates the popliteus and what is its function?
Tibial nerve
Laterally rotate femur unlocking the joint so flexion can occur