elbow, forearm and wrist Flashcards
what are the bones of the elbow, forearm and wrist *
humerus - in arm but involved in the lebow joint
radius
ulnar
carpal bones
- proximal row - scaphoid, lunate, triquetrum, pisiform
- distal row - trapezium, trapeziod, capitate, hamate
summarise the organisation of the bones in the elbow forearm adn wrist *
lateral and medial epicondyles of humerus are for muscle attachment
the condyles of humerus (capitulum and trochlear) are part of the elbow joint with teh radius and ulnar
distal ends of radius and ulnar form the proximal part of the wrist joint - with the proximal row of carpal bones
(green on diagram is points of muscle attachment)
describe the elbow joint *
it is a synovial hinge joint between the humerus and the radius and ulnar
the capitulum is a rounded condyle (hemispherical) - articulates with the radius (only in full flexion)
trochlear is bobbin shaped - articulates with the coronoid process of the ulnar
anteriorly on the humerus are the radial and coronoid fossa
posteriorly on the humerus is the olecranon fossa
ligamenst stabalise the joint and allow pronation/supination movements
describe the bones of the forearm and identify features on a diagram *
radius and ulnar are parallel long bones with a straight shaft
styloid process of ulnar, and styloid process of radius are for muscle attachment
the interosseous membrane separates the anterior and posterior compartments ad is a site for muscle attachments
describe the bones of the wrist *
the distal ends of the radius and ulnar articulate with the pox row of carpal bones - triquetrum. lunate and tubercle of scaphoid
they do not articulate with the pisiform because it is a sesmoid bone (this means it is embedded in tendon and muscle)
what are the compartments of the upper limb involved in this region *
anterior comp of arm
posterior comp of arm
anterior comp of arm - superficial and deep comp
posterior comp of arm
what muscles of the anterior comp of arm are involved in the elbow joint *
biceps
brachialis
how are the biceps involved in the elbow joint *
teh 2 heads merge to form a tendon = this attaches to radial tuberosity
heads also form an aporneurosis that merges with the facia of the region
these attachments act across the elbow joint
supinator
how is the brachialis invoved in the elbow joint *
attahes at shaft of humerus and at coronoid process of ular
it is a flexor of the elbow joint
what are the muscles of the posterior comp of arm involved in elbow joint *
triceps and anconeus
how are the triceps invoved in the elbow joint *
they form a distal tendon
it crosses elbow joint
causes extension of elbow
how is the anconeus involved in the elbow joint *
stabalisation
summarise the organisation of the forearm muscles *
the hand and wrist are operated by remote control by these muscles - the muscles go up to the digits
muscles originate form distal humerus, and ulnar and radius
flexors (pronators) anterior
extensors (supinators) posterior
what are the muscles of the superficial compartment of the forearm *
pronator teres (PT)
flexor carpi radialis (FCR)
palmaris longus (PL)
flexor digitorum superficialis (FDS)
flexor carpi ulnaris (FCU)
what are the muscles of teh deep compartment of the forearm *
flexor digitorum profundis (FDP)
flexor pollicus longus (FPL)
pronator quadratus (PQ)
describe the organisation of teh anterior compartment of the forearm *
in the superficial compartment there is a proximal attachment called the common flexor tendon that attaches to the medial epicondyle of humerus
pronator teres, flexor carpi radialis. palmaris longus, flexor carpi ulnaris and flexor digitorum superficialis attach here - these are teh muscles form the superficial anterior comp of forearm
the muscles also attach on the shaft and interosseous membrane as in pic
technique for remembering the muscles that originate form the common flexor origin *
pic
describe the facia of teh forearm
the flexor retinaculum is a band of connective tissue that covers everything passing into wrist including the median nerve, so when wrist flexes and extends stuff doesnt pop out
palmaris longus is a small muscle with a long tendon which goes over wrist region - connects to the palmar aporneurosis. muscle is not always present but aporneurosis is
aporneurosis fans over palm and protects things under it
what are the muscles of the posterior compartment of teh forearm and what are their function*
they are the extensor muscles
move the wrist
- extensor carpi radialis longus
- extensor carpi radialis previs
- extensor carpi ulnaris
move the digits
- extensor digitorum
- extensor indicis
- extensor digit minimi
move the thumb
- abductor pollicus longus
- extensor pollicus bravis
- extensor pollicus longus
other muscles
- brachioradialis
- supinator
explanation of how the terminolgy can help with the muscles
Forearm muscles can be classified into functional groups:
Flexors (anterior) and Extensors (posterior)
Movers of the wrist (the “carpi” muscles) act on the radial (radialis) or ulnar (ulnaris) aspects of the forearm.
Movers of the digits:- act on groups of digits (digitorum muscles) or on individual digits (pollicis (thumb), indicis (index finger) digiti minimi (little finger)) (these muscles also contribute to wrist movements).
Also note that if there’s a longus, there’s a brevis; if there’s a superficialis, there’s a profundus.
The main complications are the muscles involved in pronation (anterior) and supination (posterior).
what are the boundaries of teh anatomical snuff box *
the extensor pollicus brevis tendon
the extensor pollicus lingus tendon
the abductor pollicus longus tendon is in this region too
what is teh clinical importance of the anatomical snuff box *
branch of radial artery is in this region
also can palpate the scaphoid bone - prone to fractuer when fall on hand - blood supply isrecurrent so goes down and back along bone - meaning blood supply is from distal end
if get avascular necrosis - stop blood flow to wrist = disability of wrist
what is teh carrying angle *
the deviation fo the long axis of the radius and ulnar from the humerus in extension
10-15degrees in men
>15 in women
describe the radio-ulnar joints *
proximal joint: uni-axial pivot-type synovial joint between proximal ends of radius and ulnar
the annular ligament of radius holds the head of radius in place in the joint - radius rotates in this, it attaches the radius to the margins of the radial notch of the ulnar
there is also a distal radio-ulnar joint - pivot type synovial joint that allows the radius to rotate around the distal ulnar. the articualr surfaces are held together by a triangular fibrocartilage articular disk
pronator teres and pronator quadratus wrap around lateral side of radus - when contract they pull the radius over the ular = pronation
the radius is directly articulated to the proximal carpal bones of wrist
the ulnar is not directly articulated to the triquetrum carpal bone - there is a fibrous disk between them - this si attached to the styloid process of ulnar - when radius crosses over ulnar in supination the disk is dragged over
what are the movements of the elbow joint, and what are the muscles involved *
flexion
- brachialis
- biceps
- brachioradialis
- some assisstance from pronator teres
extension
- triceps
- (anconeus - but mainly stabalisation)
what are the movements of the radio-ulnar joints and what are the msucles involved *
supination
- supinator
- biceps
- (EPL. ECRL)
pronation
- pronator quadratus
- pronatore teres
- (FCR, PL, brachioradialis)
hwo are the biceps involved in supination*
the tendon attachs to the radial tuberosity
in pornation the tendon is stretched and pulled
biceps contract = bone rotates
summarise pronation and supination *
when pronator teres and pronator quadratus contract they pull radius over ulnar and cause supination
when arm is pronated - supinator is wrapped round the radius - when contracts it pulls radius to supinated position
biceps are attached to the radial tuberosity - when arm is pronated the biceps are pulled posteriorly, so when they contract, they supinate the radius
what are the movements of the wrisyt joint and the muscles involved *
flexion
- FCR and FCU - work together for stringest flexion
- long flexors of thumb and fingers
- (PL and APL)
extension
- ECU, ECRL and ECRB - work together for strongest extension
- long extensors of thumbs and fingers
radial deviation (abduction)
- APL
- FCR
- ECRL
- ECRB
ulnar deviation (adduction)
- ECU, FCU
circumduction
what are teh arteries of the elbow, wrist and forearm *
profunda brachii divides at the elbow (level of radial neck) to form the ulnar and radial arteries
radial artery travels down lateral aspect of forearm undercover of brachioradialis muscle, crosses floor of anatomical snuff box
ulnar medial in anterior compartment of forearm, lateral to FCU (ulknar nerve is between FCU and artery) - has common interosseous branch which immmediately branches into anterior and posterior interosseous arteries - posterior pierces the interosseous membrane and runs posteriorly, anterior stays anterior
both contribute to vessels of hand
what are the veins of the elbow, forearm and wrist *
cephalic vein runs up laterally - superficial
basilic medially - superficial
tehy aroise form the dorsal venous arch of hand
connected at the cubital fossa by the median cubital vein - phlebotomy
deep veins follow the arteries in pairs - these are venae comitantes
–
deep and superficial veisn are connected with valves - allowing one way flow from superficial to deep system
summerise the lymphatic drainage of the elbow, forearm and wrist *
superficial and deep system
run with veins
have cubital lymph nodes
describe the musculocutaneous innervation of the forearm *
c5 6
becomes the lateral cutaneous nerve of the forearm - provides sensory innervation
describ ethe median nerve innervation of the forearm *
lies anterior to elbow medial to brachcial artery - risk of damage form supracondylar fracturesof teh humerus
no branches to muscles o upper limb
as reaches elbow branches
descends in forearm bewteen head of pronator teres
main nerve to muscles of forearm - some originate at distal poart of humerus
supplies - pronator teres, FDS, lateral prtion of FDP (to index and middle fingers), FCRm pronator quadratus, palmaris longus
at anteriro wrist it lies between tendons of FDS and FDP and deep to palmaris longus - then enters hadn through carpel tunnel
c6-t1
describe the ulnar nerve’s innervation of the forearm *
lies behind the medial epicondyle at elbow
pass into forearm between heads of flexor carpi ulnaris
descends on medial side of forearm
main nerve of the hand
c8 t1
supplies the flexor carpi ulnaris and the flexor digitorum profundus (medial half, to digits 4 5)
sensory supply to medial aspect of ventral forearm
at wrist it lies between FCU and ulnar artery and passes into hand
describe th4e radial nerve’s innervation of the foreearm *
supplies all muscles of posterior compartment of upper arm and forearm and cutaneous innervation of hand
passes around humerus at midshaft in radial groove - easily damaged
supplies triceps in arm
couses via anterior comp of upper arm more distally
divides above level of elbow into superficial branch - the superficial radial nerve (sensory) adn deep branch of radial nerve that descends between heads of teh supinator to become posterior interosseous nerve ( motor). it ends as a pseudoganglion belwo the extensor retinaculum
The radial nerve supplies:
- Brachioradialis
- ECL
The deep branch of the radial nerve supplies:
- ECRB
- Supinator
The posterior interosseous nerve supplies:
- ED
- ED minimi
- ECU
- APL
- EPB
- EPB
- E indicis
places where nerves are likely to get damaged *
median nerve above elbow and in wrist
ulnar - at medial epicondyle nad wrist
axillary - just below shoulder joint
radial - on shaft of humerus
describe the flexor retinaculum *
thick band of connective tissue
protect stuff passing from forearm to plamarregion eg median nerve and tendons
it connects to bony features on eait side of wrist in carpal region
what are the ligaments that stabalise the elbow joint *
the medial (ulnar) collteral ligaments
the lateral (radial) collateral ligaments
the annular ligament (part of the proximal radio-ulnar joint)
clinical significance of teh olecranon bursa *
it os over teh olecranon and frequenctly becomes inflamed
test range of flexion at wrist
should be 2 pics - if not see living anatomy wrist lecture
test range of extension at wrist
test radial deviation
test range of ulnar deviation
identify the extensor tendons of the wrist
palpate the ECRL
Finger A indicates the base of the third metacarpal. Finger B moves laterally and proximally, seeking the base of the second metacarpal
locate APL
