Chapter 17 - The Elbow Flashcards
What are the functions of the elbow?
- enables proper positioning of the hand
- allows transmission of power from the shoulder to the hand
- augmenting the versatility and agility of the UE
Where does the anterior joint capsule originate and insert?
Origin = distal humerus proximal to radial and coronoid fossa Insert = distally into the rim of the coronoid and annular ligament
Where does the posterior joint capsule attach?
Attaches distally along the articular margin of the sigmoid notch and proximal aspect of olecranon process
What type of joint is the humeroulnar joint?
Uniaxial hinge joint (between trochlea of humerus and trochlear notch of ulna)
What is the capsular pattern of the humeroulnar joint?
Flexion, extension
What are the resting and closed packed positions of the humeroulnar joint?
Resting = 70 elbow flexion, 10 supination Closed = extension and supination
What type of joint is the humeroradial joint?
Uniaxial hinge joint (between capitullum and radial head)
What is the capsular pattern of the humeroradial joint?
Flexion, extension
What are the resting and closed packed positions of the humeroradial joint?
Resting = full extension and full supination Closed = elbow flexed to 90, forearm supinated to 5
What causes Nursemaid’s Elbow?
Caused by a sudden pull on extended, pronated arm causing a dislocation of the radial head
What type of joint is the proximal radioulnar joint?
Uniaxial pivot joint (between radial head and radial notch of ulna)
What is the capsular pattern of the proximal radioulnar joint?
Equal limitation of supination and pronation
What are the resting and closed packed positions of the proximal radioulnar joint?
Resting = 35 supination, 70 elbow flexion Closed = 5 supination
What are the 3 components of the medial collateral ligament?
1) anterior bundle
2) transverse bundle
3) posterior bundle
What shape is the MCL? With what other structure does it form a tunnel?
- fan-shaped
- FCU, tunnel for ulnar nerve
What shape is LCL?
Cord-like structure
What is the function of the LCL?
- to maintain the humeroulnar and humeroradial joints when the elbow is loaded in supination
- stabilizes proximal radioulnar joint during full supination and pronation
What is the function of the annular ligament?
Checks displacement of the radial head
List the elbow flexors
Biceps Brachii Brachialis Brachioradialis Pronator Teres ECRL FCR FCU
List the forearm pronators
Pronator teres
Pronator quadratus
FCR
List the forearm supinators
Biceps Brachii
Supinator
List the elbow extensors
Triceps Brachii
Anconeus
What passes through the cubital tunnel?
Ulnar nerve
What forms the borders of the cubital tunnel?
Floor = MCL Roof = aponeurosis, arcuate ligament Posterior = medial head triceps Anterior = medial epicondyle Lateral = olecranon
When is the volume of the cubital tunnel greatest?
When the elbow is in extension
Moving the elbow into full flexion ________ the size of the tunnel by _________.
Flexion, 55%
What is the lateral boundary of the cubital fossa?
Brachioradialis
What is the medial boundary of the cubital fossa?
Prontator Teres
What is the proximal boundary of the cubital fossa?
Imaginary line that passes through the humeral condyles
What is the floor of the cubital fossa?
Brachialis
What is contained in the cubital fossa?
- tendon biceps brachii
- median and radial nerve
- brachial artery
- median cubital vein
Ulnar Nerve
C8 - T1
Median Nerve
C5 - T1
Radial Nerve
C5 - T1
Force Couples of the Elbow: flexion/extension
Triceps/Biceps
Force Couples of the Elbow:
pronation/supination
Pronator Quadratus/Supinator
Force Couples of the Elbow:
wrist flexion/extension
FCR, FCU, Flexor Digitorum Communis/ECRL, ECRB, Extensor Communis
What is the carrying angle of the forearm for males and females?
Males = 5-10 Females = 10-15
What constitutes cubitis valgus and varus?
Valgus = >15 Varus = < 5-10
What constitutes gunstock deformity?
An increase in cubital varus
A “Goose Egg” is caused by…
an olecranon bursitis over the olecranon process
Goals of Acute Phase
- protect injury site
- pain free ROM
- improve patient comfort by decreasing pain/inflammation
- retarding muscle atrophy
- minimize detrimental effects of immobilization
- maintain general CV fitness
- independence with HEP
Goals of Functional Phase
- restore normal joint kinematics
- improve muscle strength
- improve NM control
- restore normal strength and relationship of force couples
