Elbow joint

Elbow joint

Uniaxial hinge joint with 1 dg of freedom

Performs flex/extn

Concave/convex in the elbow joint

Convex capitulum on the concave radial head

Convex trochlea on the concave trochlear notch

Radioulnar joint

Uniaxial pivot joint

Pronation/supination

Proximal radioulnar joint

Radius spins/pivots within the radial notch of the ulna

Distal radioulnar joint

Radius rotates around the distal end of the ulna

Carrying angle

Longitudinal axis of the humerus and forearm

5dg in men, 10-15dg in women

Distal end of the humerus medial side (trochlea) is longer than lateral side (capitulum)

End feel- flexion

Soft, due to muscle bulk and adipose tissue compression

End feel- extension

Hard, due to bone on bone contact between olecranon process and olecranon fossa

End feel-supination

Firm, due to muscle and ligament tissue

End feel-pronation

Hard, due to contact between radius and ulna

Ulnohumeral joint

Close pack: extn

Open pack: 70dg flexion, 10dg supination

Radiohumeral joint

Close pack: 90dg flexion, 5dg forearm supination

Open pack: full extn and supination

Proximal radioulnar joint

Close pack: 5dg supination

Open pack: 70dg flex, 35dg supination

Brachialis OIAN

O: distal half of humerus, anterior surface

I: coronoid process and ulnar tuberosity of ulna

A: elbow flexion

N: musculotaneuous nerve (C5-C6)

Biceps brachii OIAN

O: supraglenoid tubercle of scapula (long head); coracoid process of scapula (short head)

I: radial tuberosity of radius

A: elbow flexion and forearm supination

N: musculotaneous nerve (C5-C6)

Brachioradialis OIAN

O: lateral supracondylar ridge on humerus

I: styloid process of radius

A: elbow flexion

N: radial nerve (C5-C6)

Triceps OIAN

O: infraglenoid tubercle of scapula (long head); inferior to the greater tubercle on posterior humerus (lateral head); posterior surface of humerus (medial head)

I: olecranon process of ulna

A: elbow extn

N: radial nerve (C5-C6)

Anconeus OIAN

O: lateral epicondyle of humerus

I: lateral and inferior to olecranon process of ulna

A: assists in elbow extn (NOT A PRIME MOVER IN ANY JOINT ACTION)

N: radial nerve (C5-C6)

Pronator teres OIAN

O: medial epicondyle of humerus and coronoid process of ulna

I: lateral aspect of radius at midpoint

A: forearm pronation and assist in elbow flex

N: median nerve (C6-C7)

Pronator quadratus OIAN

O: distal ¼ of ulna

I: distal ¼ of radius

A: forearm pronation

N: median nerve (C8-T1)

Supinator OIAN

O: lateral epicondyle of humerus and adjacent ulna

I: anterior surface of proximal radius

A: forearm supination

N: radial nerve (C6)

Biceps, brachialis, brachioradialis

Elbow flexion

Triceps, anconeus

Elbow extn

Pronator teres, pronator quadratus

Forearm pronation

Biceps, supinator

Forearm supination

Lateral epicondylitis

“Tennis elbow”

Overuse condition affecting common extensor tendon

Medial epicondylitis

“Golfer’s elbow”

Inflammation of common flexor tendon that attaches at the medical epicondyle

Nursemaid’s elbow

Radial head subluxes from under the annular ligament when a distraction force is placed on the forearm

Sprain of ulnar collateral ligament (UCL)

Partial or fully torn ulnar collateral ligament

Bony landmarks of the humerus

Spiral groove: groove spiraling around shaft of humerus proximal and lateral to distal and medial

Trochlea: middle portion of distal end, convex articular surface

Capitulum: convex lateral aspect of distal end, lateral to trochlea

Medial epicondyle: medial aspect of distal end, just proximal and medial to trochlea, larger and more prominent than lateral epicondyle

Lateral epicondyle: lateral aspect of distal end, just proximal and lateral to capitulum

Lateral supracondylar ridge: ridge extending proximally from lateral epicondyle

Olecranon fossa: depression at posterior aspect between medial and lateral epicondyle, space for olecranon process of ulna during extension

Bony landmarks of the ulna

Olecranon process: posterior aspect of proximal end, forms prominent point of elbow

Trochlear notch: proximal, anterior, concave surface, distal articulating surface of elbow joint, articulates with trochlea

Coronoid process: small protuberance on lateral surface, distal to trochlear notch

Radial notch: lateral aspect of coronoid process, distal to trochlear notch

Ulnar tuberosity: small protuberance on anterior surface, distal to coronoid process

Styloid process: pointed protuberance on posterior medial aspect at distal end

Head: distal end, radius moved over head during supination and pronation

Bony landmarks of the radius

Head: round, proximal end, depression in superior surface

Radial tuberosity: small protuberance on anterior and medial aspect of proximal end

Styloid process: rounded protuberance on posterior lateral aspect of distal end