elbow Flashcards
describe the elbow
- hinge joint that allows movement in sagittal plane i.e. flexion and extension
what does elbow joint involve articulation of?
- humerus, capitulum, trochlea, head of radius and ulna
what does inferior portion of humerus have?
- medial and lateral aspect
- two ridges and two protuberance on each side
which ridge can be palpated?
- medial ridge; put fingers around arm and displace fingers in lateral part of upper arm greeting elbow
what epicondyle is more pronounced?
- medial is more pronounced than lateral one
what two structures articulate with radial head and ulna in distal area?
- capitulum and trochlea
describe capitulum
- articulates with facet of radial head
describe trochlea
- medially located
- articulates with ulna
what is the radial fossa? what does it do?
- small shallowed depression on humerus
- gives space to the head of radius to fit when elbow bends and generates full flexion
what is the coronoid fossa? what does it do?
- depression that fits with coronoid process of ulna
- helps during full flexion of elbow
what articulates with humerus capitulum?
- articular area of proximal part of radius articulates with facet of radius
describe radial tuberosity
- inferior to neck of radius
- provides insertion for biceps muscle
what does ulna contain?
- coronoid process
what is the radial notch?
- surface that provides attachment for ligaments
- articular surface for head of radius
what is the sublime tubercle?
- found medially
- anterior bundle of medial ulnar collateral ligament attaches distally
what is the olecranon fossa?
- depression that provides space for ulna to fit in during elbow extension
what is besides the olecranon fossa?
- groove for ulna nerve
what part of nerve can you palpate?
- superficial nerve can be palpated posteriorly next to medial epicondyle to feel change in sensation
what is the olecranon process?
- prominence of ulna providing attachment for triceps
what shape is proximal ulna? what does it articulate with?
- large hook - shaped structure
-articulates with distal humerus and radius head
what is the radioulnar joint?
- articulation between ulnar and radius at proximal/ distal end
- work together to produce pronation + supination
what are the layers of the radioulnar joint?
- membrane layer of articular capsule around entire joint
- fibrous layer of capsule; fibres in different directions so joint stabilised in diff moves
what is inbetween the radius and ulna ? what is it’s role?
- interosseous membrane
- provides stability and flexibility for supination and pronation
what allows the passing of arteries in interosseous membrane?
- perfusions
what are the ligaments of the proximal radioulnar joint? (4)
- lateral collateral ligament, medial collateral ligament, quadrate ligament and annular ligament
what is the lateral collateral ligament?
- originates on lateral epicondyle and inserts on head of radius
- stability during radial movements
what is the medial collateral ligament?
- originates on medial epicondyle and inserts onto ulna
- fibres provide stability on medial region of elbow
what is the quadrate ligament?
- connects radius and ulna
- provides stability and flexibility during different movements of the joint
what is the annular ligament?
- provides stability of radial head during spinning movement
what is the ligament of the distal radioulnar joint ?
- dorsal radioulnar ligament
what is the role of the dorsal radioulnar ligament?
- provides stability
what is the cubital fossa?
- triangular shaped depression over anterior aspect of elbow
- different boundaries
what are the boundaries of the cubital fossa?
- lateral= brachioradialis
- medial= pronator teres
- superior = biceps brachii
state origin, insertion and action of biceps brachii
O= short= tip of coracoid process of scapula
long head= supraglenoid tubercle of scapula
I= tuberosity of radius
A= when forearm is supinated, biceps flex
state origin, insertion and action of brachialis
O= distal half of anterior surface of humerus
I= coronoid process and tuberosity of ulna
A= flexes forearm in all positions primarily pronated
state origin, insertion and action of brachioradialis
O= lateral ridge of distal humerus
I= lateral surface of distal radius
A= effective flexor when forearm in neutral position
state origin, insertion and action of triceps
O= long- infraglenoid tubercle; lateral= humerus above radial groove; medial= humerus below radial groove
I= olecranon of ulna
A= extends forearm
state origin, insertion and action of anconeus
O= lateral epicondyle
I= lateral side of olecranon process
A= extension of elbow
state origin, insertion and action of pronator quadratus
O= anterior aspect of distal 1/4 of ulna
I= distal 1/4 of radius
action= pronator
state origin, insertion and action of pronator teres
O= medial super condyle of humerus; coronoid process of ulna
I= lateral surface of mid- shaft of radius
A= pronator and weak flexor
state origin, insertion and action of biceps brachii
O= short- tip of coracoid process
long- supraglenoid tuberosity
I= tuberosity of radius and fascia of forearm
A= supinates forearm
state origin, insertion and action of supinator
O= lateral epicondyle and supinator crest of humerus
I= lateral proximal end of radius (posterior)
A= generates around 90 degrees of supination
describe pronation
- radius spins and distal end will overlap the ulna
- distal radioulnar joint moves
- contraction of anconeus muscle to generate ulna abduction
describe supination
- radius and ulna are parallel to each other
- uncross radius and ulna
