elbow, forearm and wrist Flashcards
(100 cards)
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






