elbow, forearm and wrist Flashcards
radio-ulnar joint: describe the anatomy of the radio-ulnar joints; explain the movements of supination and pronation; identify the muscles responsible for these movements, list the main attachments and recall the nerve supply of these muscles
proximal radio-ulnar joint type
uni-axial pivot-type synovial joint
proximal radio-ulnar joint function
allows head of radius to rotate within annular ligament (attached to margins of radial notch of ulna)
what happens to proximal radio-ulnar joint in young children (<5)
radial head may harmlessly sublux out of position (pulled elbow) when child’s forearm is pulled suddenly, but it can be manipulated back in place on supination
distal radio-ulnar joint type
pivot-type synovial joint
distal radio-ulnar joint function
allows radius to rotate around distal ulna, with articular surfaces being held together by fibrocartilage articular disc
what movements occue at proximal and distal radio-ulnar joints
supination and pronation
2 muscles involved in supination
supinator, biceps brachii
2 muscles involved in pronation
pronator quadratus, pronator teres (shorten to pull bones round)
how is biceps brachii involved in supination
tendon attached to radial tuberosity, pulling radius around in pronation; hence when biceps contract, pulls bone back around again in supination
