elbow

Question 1

bony landmarks of elbow

• medial ridge of humerus and medial epicondyle
• lateral ridge of humerus and lateral epicondyle
• capitulum
• trochlea of humerus
• radial fossa
• coronoid fossa
• articular area of proximal radius
• neck of radius
• radial tuberosity
• coronoid process of ulna
• radial notch
• sublime tubercle
• olecranon fossa
• groove for ulnar nerve
• olecranon

Answer 1

• origin for muscles and medial collateral ligament
• origin for muscles and lateral collateral ligament
• is convex and articulates with facet of radial head forming humeroradial joint
  -medial, articulates with trochlear notch of ulna forming humeroulnar joint
• shallow depression on humerus above capitulum allowing room for radius during flexion
• shallow depression on humerus above trochlea allowing room for ulna during flexion
  -articulates with radial notch of ulna forming proximal radioulnar joint, also has a concave head that articulates with capitulum
• surrounded by anular ligament and medially gives attachment for quadrate ligament
• anteromedial below neck, insertion for biceps brachii
• origin for muscles, insertion for brachialis and ulnar collateral ligament
• lateral aspect of coronoid process, attachment for anular ligaments, articulates with medial head of radius
• medial aspect of cornoid process, origin for flexor digitorum superficialis, attachment for ulnar collateral ligament
• large depression allowing room for olecranon of ulna during extension
• depression lateral to medial epicondyle for ulnar nerve
• projection of proximal ulna, attachment for muscles and ulnar collateral ligament

Question 2

elbow arthrology

• type of joint and movements
• what articulated with what at elbow
• joints between radius and ulna
• fibrous joint capsule
• synovial membrane
• lateral/radial collateral ligament
• medial/ulnar collateral ligament
• quadrate ligament
• annular ligament
• interosseus membrane
• dorsal radioulnar ligament
• cubital fossa

Answer 2

• hinge, flexion-extension
• capitulum and trochlea articulate with head of radius and ulna respectively
• proximal and distal radioulnar joint (distal has fibrous articular cartilage), for pro and supination
• fibres in diff directions providing stability of joint in diff direction of movement
• secrete synovial fluid which lubes articular surfaces
• lateral epicondyle to anterior head of radius. provides stability to lateral side of elbow
• medial epicondyle to proximomedial surface of ulna. provides stability to medial side of elbow
• radius to ulna stabilising radioulnar joint while allowing flexibility during pro and supination
• provide stability of radial head during spinning of pro and supination
• between radius and ulna, stability and flexibility during pro and supination, attachment for muscles, gaps for arteries to pass through
• stability at distal end during pro and supination
• area of transition between arm and forearm anetrior to elbow (lateral boundary- brachioradialis, medial boundary- pronator teres, superior boundary- biceps brachii)

Question 3

movements at elbow

Answer 3

150 deg flexion, 0-5 deg extension, pronation and supination

Question 4

closed and open packed position

Answer 4

closed- 5 deg flexion, 90 deg supination
open- 90 deg flexion, 5 deg supination

Question 5

function of elbow

Answer 5

orientate hand in space
elongate and shorten arm by flexion-extension

Question 6

cocontraction

Answer 6

+ simulataneous contraction of agonist and antagonist creates joint stiffness and stability increasing accuracy
- comes at energy cost as uses double energy
clinical application- useful motor approach when learning new skills and adapting to impairment at NMJs and can allow patients to stand again when weak using lots of effort.