Clinical Orthopedics 222 Exam 3 Elbow and forearm overview

What is the difference between the forearm and elbow

The forearm does pronation and supination
the elbow does flexion and extension

The elbow complex
-what does this allow for

Allows for height and limb adjustments in order for one to position their arm correctly for functional purposes

The elbow complex
-what is this the center for
-what kind of joint

Central link in the kinetic chain of the UE
Constrained(limited/restricted) hinge joint

what is the green part highlighted

olecranon

what is the red part highlighted

coronoid process

what is the yellow part highlighted

trochlear notch

what is the blue part highlighted

radial notch

Osteokinematics of the elbow complex
-flexion

0-150

Osteokinematics of the elbow complex
extension

0-150

Osteokinematics of the elbow complex
Supination

0-80

Osteokinematics of the elbow complex
pronation

0-80

Osteokinematics of the elbow complex
capusular pattern?

Humeroulnar Joint: Flexion is more limited than extension (Flexion > Extension).
Humeroradial Joint: Limitation occurs in flexion, extension, supination, and pronation

The Elbow
-what kind of joint is this

compound synovial joint

The Elbow
compound synovial joint
-what joints make this up

Humeroulnar (trochlear) joint
Humeroradial joint
Proximal Radioulnar joint

Humeroulnar Joint
-what bones make this up

Olecranon of the ulna
trochlea of humerus

Humeroulnar joint
-what does this give

gives the most structural stability

Humeroulnar joint
-what motion does this joint do

Pure flexion and extension

Humeroulnar joint
pure flexion and extension
-what limits flexion

Passive flexion is limited by soft tissue approximation, bony, ligament and posterior capsule, triceps

Humeroulnar joint
pure flexion and extension
-what limits extension

Extension is limited by biceps/brachialis/supinator tightness

Humeroulnar joint
pure flexion and extension
-what limits extension passively

bony (olecranon), Ulnar collateral ligament, anterior capsule

in the humeroulnar joint
which bone is convex and which is concave

trochela is convex
olecranon is concave

Carrying angle (cubital valgus)
Trochlea tilt

4 degrees in males
8 degrees in females

Carrying angle (cubital valgus)
Cubital valgus

10 degrees in males
13 degrees in females

Carrying angle (cubital valgus)
Most obvious in what movtion, how can it be deviated

most obvious in extension
altered with trauma

Carrying angle (cubital valgus)
what does this create

the ability to function
-carry something by your side (accounts for hips, etc)

Humeralradial joint
-what bones makes this joint up

Radial head and capitulum of the humerus

Humeralradial joint
-what kind of joint is this

a hinge joint
-it does flexion and extension
-some supination and pronation due to radial head speen

in the humeralradial joint
which bone is convex
which bone is concave

capitulum is convex
radial head is concave

which 2 joints do what (% wise)

humeroulna and humero radial provide 50% of the entire stability of the elbow

humeroulna and humero radial provide 50% of the entire stability of the elbow
-which joint makes up the most stability

the humeroulna

humeroulna and humero radial provide 50% of the entire stability of the elbow
the humeroulna joint provides the most stability
-the rest comes from where

muscles and ligaments

Proximal Radioulnar joint
-what kind of joint

Pivot joint
and has
-radial head
-radial notch of the ulna
-annular ligament

Proximal Radioulnar joint
-what does it have
-what motions does it do

-interosseous membrane
-pronation/supination

Proximal Radioulnar joint
if the humerus is fixed
-what does the radius do

pronation and supination is ONLY the radius moving
(radial head spin )

Proximal Radioulnar joint
if the humerus is fixed
-articulation where

at the elbow, distal radiaulnar joint and radiocarpal joint

what parts of the radius are convex or concave

the radial head is convex
the radial notch is concave

A note on pronation/supination
-what only only happens during the artiulcation at the elbow, distal radioulnar joint and radiocarpal joint

only radial head movements occur here

Functional Movement of The Elbow Complex
flexion/extension arc

100 degrees (total)
30 degrees of extension to 130 degrees of flexion

Functional Movement of The Elbow Complex
Pronation/supination arc
-what compensation might occur here

100 degrees (total)
50 degrees into pronation, 50 degrees into supination
shoulder IR/ER

What part is green highlighted

joint capsule

what part is blue highlighted

annular ligament

what part is red highlighted

ulnar collateral ligament

what part is yellow highlighted

radial collateral ligament

Ligaments of the elbow complex (medial side)

Ulnar/Medial collateral ligament

Ligaments of the elbow complex (medial side)
Ulnar/Medial collateral ligament
-functionally what
-what joint is what

Functionally most important to provide stability against valgus stress Humeroradial joint is the secondary stabilizer of valgus load

Ligaments of the elbow complex (medial side)
Ulnar/Medial collateral ligament
-limits what
-what does this provide

limits end range elbow extension
provides stability to medial elbow

Ligaments of the elbow complex (medial side)
Ulnar/Medial collateral ligament
-how many components

3 components
-anterior bundle
-posterior bundle
-transverse bundle

Ligaments of the elbow complex (lateral side)

Radial collateral ligament
annular ligament
joint capsule

Ligaments of the elbow complex (lateral side)
Radial collateral ligament

Made up of annular ligament and accessory collateral ligament
Stability to lateral aspect of elbow against varus forces
-Secondary restraints of lateral elbow are bony articulation, joint capsule and extensor muscles
Prevents posterior translation of radial head

Ligaments of the elbow complex (lateral side)
Annular ligament

Originates from lateral humerus at center of trochlea & capitellum
Maintains relationship between head of radius and the humerus and ulna

Contributions to elbow complex stability
Valgus stability
-elbow extended

anterior capsule, MCL, bony articular

Contributions to elbow complex stability
Valgus stability
-elbow flexed

MCL

Contributions to elbow complex stability
Varus stability
-elbow flexed

joint articulation, LCL

Contributions to elbow complex stability
Varus stability
-elbow extended

anterior capsule, joint articulation, LCL

Contributions to elbow complex stability
Anterior displacement
-elbow extended

anterior joint capsule, trochlea-olecranon articulation

Contributions to elbow complex stability
Posterior displacement
-elbow extended

Anterior capsule, radial head against capitellum, coracoid against trochlea

Contributions to elbow complex stability
Distraction
-elbow extended

anterior capsule, LCL, MCL, triceps, biceps, brachial, brachioradial, forearm muscles

Contributions to elbow complex stability
Distraction
-elbow flexed

LCL, MCL, capsule

Muscles of the elbow complex
-elbow flexion

Brachialis, Biceps Brachii, Brachioradialis, Pronator Teres, Flexor Carpi Ulnaris

Muscles of the elbow complex
-elbow extension

Triceps, anconeus

Muscles of the elbow complex
-forearm supination

supinator, biceps brachii

Muscles of the elbow complex
-forearm pronation

Pronator Quadratus, Pronator Teres, Flexor Carpi Radialis

Muscles of the elbow complex
-prime flexors?

Biceps brachii
Brachialis
brachioradialis

Muscles of the elbow complex
-what is the workhorse of flexion

brachialis

Muscles of the elbow complex
-weak flexors

pronator teres
flexor carpi radialis
flexor carpi ulnaris
extensor carpi radialis longus

Muscles of the elbow complex
-most of the flexors attach to what

to the radius (humeroradial joint)
-pulls radius proximally against humeroradial joint

Muscles of the elbow complex
-brachialis attaches to what so what doesn’t do

Brachialis attaches to ulna so the position of the forearm doesn’t affect it (sup or pro)

Muscles of the elbow complex
-Elbow Extensors

triceps brachii
Anconeus

Muscles of the elbow complex
Elbow Extensors
-triceps

Long head: also performs shoulder extension
Medial Head: workhorse of the elbow

Muscles of the elbow complex
Elbow Extensors
-anconeus

Stabilizes ulna & subanconeus bursa
-To avoid impingement

Muscles of the elbow complex
-Elbow pronators

Pronators teres
Pronators quadratus

Muscles of the elbow complex
-Secondary Elbow pronators

flexor carpi radalis
palmaris longus

Muscles of the elbow complex
-where do the pronators originate

Orginate on the humerus/ulna

Muscles of the elbow complex
-where do the pronators attach

attach to the radius/hand

Muscles of the elbow complex
-pronator teres has 2 heads which are

humeral head (medial epicondyle) / ulnar head (medial coronoid process)

Muscles of the elbow complex
-Supinators

Biceps
Supinators

Muscles of the elbow complex
Supinators
-Biceps

Greatest supinator with elbow flexion to 90 degrees

Muscles of the elbow complex
Supinators
-supinator

Workhorse of supinators

what part is highlighted in red

brachioradialis

what part is highlighted in blue

extensor carpi radialis
extensor carpi longus
extensor carpi brevis

what part is yellow

extensor digitorum

what part is green

extensor digit minimi (little finger )

what part is purple

extensor arpi ulnaris (ulnar deviation)

what part is orange

anconeus

what part is yellow

supinator

what part is red

abductor pollicis longus

what part is orange

extensor pollicis longus
extensor pollicis brevis

what part is light blue

extensor indicis

Why can you move your fingers while you are pronated and/or supinated

Because their muscle attachment is to the distal HUMERUS – so it doesn’t matter what position the forearm is in

nerves of the elbow/forearm

Musculocutaneous nerve
Radial Nerve
Median Nerve

nerves of the elbow/forearm
Musculocutaneous nerve

innervates the primary elbow flexors
(except the brachioradialis)

nerves of the elbow/forearm
Radial Nerve

innervates the primary elbow extensors

nerves of the elbow/forearm
Median Nerve

innervates the primary elbow pronators

nerves of the elbow/forearm
musculocutanoeus
-what muscles

brachialis, biceps brachii

nerves of the elbow/forearm
radial
-what muscles

triceps, anconeus, brachioradialis
Posterior interosseous
-supinators

nerves of the elbow/forearm
median
-what muscles

pronator teres, flexor carpi radialis
-anterior interosseous
pronator quadratus

nerves of the elbow/forearm
ulnar
-what muscles

flexor carpi ulnaris

Soft tissue structures
-interosseous membrane

between ulna and radius
distributes forces
muscle attachements

Soft tissue structures
interosseous membrane
-it especially distributes which force

compressive forces

Soft tissue structures
-bursa

a small, fluid-filled sac that acts as a cushion and gliding surface between bones, tendons, muscles, and skin around joints