Upper Limb Flashcards
Where does scapula extend from?
Ribs 2-7 when arm by side
Why is rotation of the scapula required
For full abduction
Describe osteology of clavicle
Medial 2/3 convex anteriorly and circular cross-section
Lateral 1/3 convex posteriorly and flat cross-section
Costoclavicular ligament?
Attaches clavicle to 1st costal cartilage
First bone to ossify in foetus?
Clavicle - only long bone which develops in a membrane
Function of clavicle?
Transmit force from upper limb to axial skeleton
Acts as a strut to hold arm free from trunk
What may pierce the clavicle?
Supraclavicular nerves
Most commonly frac bone?
Clavicle - usually at junction between middle and lateral 1/3
Describe the humeral head
1/3 of a sphere facing upwards and backwards
What separates greater and lesser tubercle of humerus?
Bicipital groove - containing long head of biceps tendon
What passes medially and wraps round surgical neck of humerus?
Axillary nerve
Posterior circumflex humeral artery and vein
Radial nerve path around humerus?
Sits in spiral groove which lies posteriorly on the shaft and winds around - between the medial and lateral heads of triceps
Osteology of distal humerus
Rounded capitulum laterally - for articulation with radial head
Trochlea medially - for articulation with trochlear notch of ulna
Medial and lateral epicondyles - these are extracapsular
Where does the ulnar nerve lie relative to the distal humerus?
In the groove on the posterior aspect of the medial epicondyle
Osteology of radius and ulna
Radius consists of head, neck, radial tuberosity shaft and expanded distal end
Ulna contains olecranon, trochlear fossa, coronoid process with its radial notch for articulation with radial head, shaft and small distal head
Both have a distal styloid process
Carpal bones?
Lateral to medial:
Scaphoid lunate triquetral pisiform
Trapezium trapezoid capitate hamate
Shape of carpal bones overall?
How is this shape maintained?
Arched transversely with plamar aspect being concave
Maintained by individual bones, which are broader posteriorly than anteriorly
Also by flexor retinaculum passing from scaphoid/trapezium laterally to pisiform and hook of hamate medially
What surface of the triquetrum does pisiform sit on?
What sits next to it distally?
Palmar surface
Hook of hamate
Shoulder flexors? (3)
Anterior delt
Pec major
Coracobrachialis
Shoulder extensors? (3)
Lat dorsi
Teres major
Posterior delt
Internal rotators of shoulder? (4)
Pec major
Lat dorsi
Subscapularis
Anterior delt
External rotators of shoulder? (3)
Infraspinatus
Teres minor
Posterior delt
Articular surfaces of sternoclavicular joint?
Ligament? Function?
Medial end of clavicle and manubrium of sternum with an intra-articular disc
Costoclavicuar cartilage - attaches medial clavicle to first costal cartilage
Acts as a fulcrum so when lateral clavicle is raised (e.g. shrugging), medial is depressed
Articular surfaces of ACJ?
Nearby ligaments?
How is movement induced?
Lateral clavicle with acromion process - has an incomplete articular disc, surrounded by capsule
Coracoclavicular ( lateral clavicle *coracoid process - conoid is more medial than trapezoid ligament)
Passively with scapular movement
Which aspect of glenohumeral joint is not covered by rotator cuff?
Inferior
Insertion of rotator cuff tendons?
Supra/Infra-spinatus and teres minor to greater tuberosity of humerus
Subscapularis to lesser tuberosity
Path of supraspinatus?
Passes over apex of shoulder, beneath acromion and coracoacromial ligament, from which it is separated by the subacromial bursa, then to greater tuberosity
Relationship between joints in the shoulder girdle and shoulder movement?
All but very slight glenohumeral movements are always accompanied by movements of the scapula on the clavicle and clavicle on manubrium.
Muscles involved in full abduction?
Supraspinatus initiates to 15 degrees
Deltoid takes over to 90 degrees
90-180 degrees is by rotation of the scapula by trapezius and serratus anterior
Relationship between glenohumeral, scapular and sternoclavicular movements?
As soon as abduction commences rotation of scapula begins
Movements of scapula occur with reciprocal movements of sternoclavicular joint eg elevate the shoulder and sternoclavicular joint is depressed - move shoulder forwards and the joint moves backwards
What muscles elevate the shoulder?
Trapezius and elevator scapulae
What depresses the shoulder?
Gravity, pec major and pec munor
What protracts the scapula?
Serratus anterior and pec minor
What retracts the scapula?
Rhomboids and middle fibres of trapezius
What muscles rotate the scapula?
Trapezius and serratus anterior
How will fragments of clavicle move in a fracture?
Trapezius unable to support weight of arm
Lateral fragment is depressed down and drawn medially by shoulder adductors and broken ends overlap.
Slight elevation of medial fragment due to sternocleidomastoid
How can someone adduct arm in supraspinatus tendon rupture?
Tilt body to injured side so gravity pulls limb away from trunk and deltoid activates
Which nerve supplies the serratus anterior?
Roots?
How is it commonly damaged?
Long thoracic nerve
C5-7
Neck, breast or axillary surgery ( = winging of scapula)
Describe articulations of elbow joint
3 articulations within 1 synovial cavity
Humeroulnar - trochlea of humerus and trochlear notch of ulna (hinge joint)
Humeroradial - capitulum and radial head (ball and socket joint)
Proximal radioulnar - head of radius and radial notch of ulna (pivot joint)
Describe structure of elbow joint capsule
What structures are extracapsular?
Thin and lax anteriorly and posteriorly
Thickened at sides to form medial and lateral collateral ligaments
Lateral ligament is attached to annular ligament, which holds the radial head in place
Medial and lateral epicondyles are extra capsular
Elbow flexors?
Biceps, brachial, brachioradialis, forearm flexors
Elbow extenders?
Triceps
Aconeus
Elbow pronators
Pronator teres
Pronator quadratus
Elbow supinators
Biceps
Supinator
What are the articular surfaces of the wrist?
Distal radius and head of ulna
Proximal scaphoid, lunate, triquetral
Head of ulna separated from carpus by articular disc
What type of joint is wrist?
Condyloid joint
Allows flexion, extension, abduction and adduction
Wrist adductors?
Flexor carpi ulnaris
Extensor carpi ulnaris
Wrist abductors?
Flexor carpi radialis
Extensor carpi radialis longus
Extensor pollicis longus
Abductor pollicis longus
What type of joint is thumb CMC?
Saddle joint
Allows flexion, extension, abduction, adduction and opposition
Other CMC joints have only limited gliding movement
