Arm, Elbow and Forearm Flashcards
What is valgus deviation?
lateral deviation of distal segment relative to proximal segment (in the coronal plane)
What is varus deviation?
medial deviation of distal segment relative to proximal segment (in the coronal plane)
What are the 3 joints of the elbow complex?
humeroulnar joint, humeroradial joint, proximal radioulnar joint
Structural classification of humeroulnar joint?
synovial hinge
Movements of humeroulnar joint?
flexion, extension
Structural classification of humeroradial joint?
synovial hinge
Movements of humeroradial joint?
flexion, extension
Structural classification of proximal radioulnar joint?
synovial pivot
Movements of proximal radioulnar joint?
supination, pronation
What are the 2 joints in forearm pronation-supination?
proximal radioulnar, distal radioulnar
Structural classification of distal radioulnar joint?
synovial plane
What does the medial collateral ligament resist?
valgus force
What does the lateral collateral ligament complex consist of?
radial collateral ligament, lateral ulnar collateral ligament and annular ligament
What does the radial collateral ligament resist?
varus and posterolateral instability
What does the lateral ulnar collateral ligament resist?
varus and posterolateral instability
What does the annular ligament resist?
lateral and distal sublaxation of the radial head
What does the articular capsule resist?
minimal (lax), may resist valgus in extension
What does the oblique cord resist?
end range supination
What does the interrosseous membrane resist?
seperation of radius/ulna
What are the 5 roles of the interrosseous membrane?
1) attachment site for muscles 2) hinge for forearm rotation 3) limit seperation of the radius and ulna 4) stabilise proximal and distal radioulnar joints 5) distribute load from radius to ulna in the proximal forearm
What are the attachments of the anterior, posterior and transverse band of the medial collateral ligament?
anterior band= medial epicondyle-coronoid process
posterior band=medial epicondyle-olecranon process
transverse band= coronoid process-olecranon process
What are the attachments of the radial collateral ligament?
lateral epicondyle-annular ligament
what are the attachments of the lateral ulnar collateral ligament?
lateral epicondyle-supinator crest of ulna
what are the attachments of the annular ligament?
anterior and posterior margins of the radial notch
what are the attachments of the oblique cord?
ulnar tuberosity to radius distal to tuberosity
What is an apophysis?
An apophysis is also a secondary ossification centre thought it does not contribute to an increase in length of the bone
When is the elbow joint capsule at most ‘lax’?
80 degrees
What is the articulation in the humeroulnar joint?
The trochlea of the humerus and the trochlea notch of the ulnar
What is the structural classification of the humeroulnar joint?
Synovial hinge joint
What movements does the humeroulnar joint do?
flexion and extension
What is the articulation at the radiohumeral joint?
Capitulum of the humerus and the head of the radius articulate
What is the structural classification of the radiohumeral joint?
synovial hinge joint
What movements does the radiohumeral joint do?
Flexion and extension
What is the articulation the proximal radioulnar joint?
Radial notch of the ulnar and the head of the radius articulate
What is the structural classification of the proximal radioulnar joint?
Synovial pivot joint
What movements doe the proximal radioulnar joint do?
Supination and pronation
when is the interosseous membrane in full lax?
pronation
when is the greatest load transmission in the interosseous membrane?
in neutral 60 degrees supination
