The Elbow and Forearm

The Elbow

A hinge joint performing flexion, extension, pronation, and supination

Anatomy Humerus

Lateral/Medial Epicondyle

Olecranon Fossa

The Elbow

Anatomy Radius

lateral bone of the forearm

Radial Tuberosity Radial Styloid

process Ulna

Medial border of the forearm

Semilunar notch Olecranon process

The Elbow

Articulations Flexion and Extension

Humeroulnar joint Humeroradial joint

Supination and Pronation Humeroradial joint Superior and inferior Radioulnar joints

The Elbow

Ligamentous support Ulnar collateral Lig.

(UCL) Divided into

sections Anterior Oblique

band Transverse

Oblique band Posterior oblique

band

The Elbow

Ligamentous Support Lateral Ulnar

collateral Lig. (LUCL)

Radial Collateral Lig. (RCL)

Annular Ligament Interosseus

Membrane

The Elbow

Supporting StructuresTypes

Static Structure Dynamic Structure

Static Structures

Includes Fibrous Capsule Collateral Ligaments Synovial membrane Fat pads

At the Olecranon Fossa (largest) Over the radial and coronoid fossae (2 small fat

pads)

Dynamic Structures

Supinator muscle - supports lateral joint and serves as false ligament

Other muscle around elbow joint

Cubital Fossa

Passing within the fossa is the Brachial artery Median Nerve Biceps Tendon Musculocutaneous

Nerve

This is called the Triangular Space

Carrying Angle

The way the forearm goes outward when at ones side.

Caused by the size of the trochlea.

Valgus (outward angulation) of 5-15 degrees is normal being greater in females.

Cubitus Valgus/Varus Gunstock deformity

A deformity of the elbow, resulting from condylar fracture at the elbow in which the forearm deviates toward the midline of the body when extended.

Isoceles Triangle

Medial and lateral epicondyles, Olecranon process. Forms a triangle in flexion and lines up in extension

Boarded laterally by the Brachioradialis and medially by the pronator teres

Eating Angle

Due to the carrying angle hand goes straight to the mouth when elbow is flexed.

Observation

Note the carrying angle Note Cubitus valgus

and/varus excessive swelling Look for normal bony

and soft tissue contours Functional position

90 degrees of flexion with hand in neutral

Range of Motion

AROM Flexion - 135-145

degrees Extension - 0-10

degrees Supination - 90

degrees Pronation - 80-90

degrees

Circulation

Brachial Artery The pulse of the

brachial artery can be felt directly medial to the biceps tendon insertion

Peripheral Nerve Injuries

Median Nerve (C6-C8,T1) innervates wrist & finger flexors & pronates forearm Pinched or compressed

as it passes under the Lig. of Struther

Weakness of the pronator teres, and motor and sensory loss

Referred as Humerus Supracondylar Process Syndrome

Peripheral Nerve Injuries

Pronator Teres Syndrome As the median nerve passes through the two heads of

the pronator teres it can be compressed In this case the pronator teres remains normal and the

other muscles supplied by the median nerve become involved down the median nerve’s motor distribution.

The motion of pronation is possible but weak Tested with Pronator Teres Syndrome Test: + sign is

tingling or paresthesia in the median nerve distribution of the forearm and hand

Pronator Teres Syndrome Test

The patient stands with the elbow in 90 degrees of flexion.

The practitioner then places one hand on the client's elbow for stabilization and the other hand grasps the client's hand in a handshake position.

The client holds this position as the practitioner attempts to supinate the client's forearm (forcing the client to contract the pronator muscles).

While holding the resistance against pronation, the practitioner extends the client's elbow

If the client's pain or discomfort is reproduced, there is a good chance of median nerve compression by the pronator teres

Pronator Teres Syndrome

Pronator Teres Syndrome Test: In 90 degrees of elbow flexion the pronator teres muscle is weaker: a positive test is indicated by tingling or parenthesis in the median nerve distribution

Peripheral Nerve Injuries Anterior Interosseus Nerve-

Pinch Deformity Sometimes pinched or

entrapped as it passes the pronator teres, leading to impairment of

Flexor pollicis longus Flexor digitorum

profundus (lateral half) Pronator Quadratus

Anterior Interosseous Nerve Syndrome or Kiloh-Nerin Syndrome- exhibited by pinch deformity: + sign is touching finger pulp-to-pulp instead of finger tip to finger tip

AIS causes no sensory loss because the AIN is a motor nerve

Peripheral Nerve Injuries

Ulnar Nerve (C7-C8, T1)- innervates flexors of wrist & finger, intrinsics of the fingers and thumb Likely to be

compressed or stretch in the Cubital tunnel

Compressed by The Cubital Tunnel Between the two

heads of the flexor carpi ulnaris muscle

Peripheral Nerve Injuries

Radial Nerve (C5-C8, T1) innervates triceps, brachiolis, brachioradialis, supinator ,& extensor muscles of wrist and fingers May be injured as it winds around behind the

Humerus in the Radial Groove. Damage can occur at time of injury or later

when the nerve gets caught in the callus of fracture healing

The extensor muscle of the arm are supplied by the radial nerve and only the triceps get spared with this injury

Peripheral Nerve Injuries

Posterior Interosseous Nerve Radial Tunnel

Syndrome The PIN can be

compressed as it passes b/t the two head of the Supinator in the Arcade or Canal of Frohse.

Compression leads to functional involvement of forearm extensor muscles and drop wrist

No sensory deficit and may mimic tennis elbow

Elbow Pathology

Lateral Epicondylities/Radiohumeral Bursitis Location: extensor carpi radialis brevis

tendon or the extensor commounis tendon Signs & Symptoms:

Pain & tenderness on the outer side of elbow Pain or weakness with gripping activities Pain with twisting motions of the wrist ( playing

tennis, using a screwdriver, opening a door or jar)

Pain with lifting objects

Lateral Epicondylitis

Causes: Chronic repetitive stress and

strain to the muscles and tendons that attach the forearm muscles to the elbow

Sudden change in activity level or intensity

Incorrect grip Incorrect grip size of racquet

(often to large) Incorrect hitting position or

technique ( usually backhand; leading with the elbow

Using a racket that is too heavy

Radial Head Fractures

MOI: FOOSH injury Elbow Dislocation Direct Blow to the area

Radial Head Fractures

Three Types or Classifications:

Type I: Nondisplaced Type II Marginal radial

fractures that are displaced

Type III: Comminuted Fractures involving the entire radial head

Elbow Dislocation

Very common in children and athletes MOI: FOOSH injury

Direct blow or twisting injury to the elbow Posterior Dislocations are most common(98%) Seldom occur in isolation – are associated with

fracture of the radial head (occur in 10%), Neurovascular involvement including brachial artery and median nerve

Elbow Dislocations

Signs and Symptoms: Extreme pain, swelling, and inability to bend the elbow Deformity with olecranon protruding posteriorly and

inferiorly Loss of elbow function Severe pain when attempting to move the elbow Numbness or paralysis in the forearm or hand below

the dislocation from pinching , stretching, or pressure on the blood vessels or nerves

Decrease or absent pulse at the wrist

Olecranon Bursitis

Inflammation of the bursa located b/t the skin and tip of the ulna

Common in contact sports such as wrestling, football, volleyball

Olecranon Bursitis

Signs and Symptoms Pain, tenderness, swelling, warmth, or redness over

the olecranon process Crepitaiton ( a crackling sound) on movement or touch Fever when infected Often painless swelling of the bursa