The Elbow Flashcards
What are the 3 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
What are the 3 joints of the elbow?
- Humeroulnar joint
- Humeroradial joint
- Proximal radioulnar joint
Describe the margins of the anterior elbow joint capsule
Originates from the distal humerus proximal to the radial and coronoid fossa
Describe the margins of the posterior elbow joint capsule
Attaches distally along the articular margin of the sigmoid notch and proximal aspect of the olecranon fossa
What is the capsular pattern for the humeroulnar joint?
Flexion > Extension
What is the resting position for the humeroulnar joint?
70 degrees of elbow flexion and 10 degrees of supination
What is the closed packed position for the humeroulnar joint?
Extension and supination
What is the humeroradial joint aka?
Radiocapitellar joint
What is the capsular pattern for the humeroradial joint?
Flexion > Extension
What is the resting position for the humeroradial joint?
Full extension and full supination
What is the closed packed position for the humeroradial joint?
Elbow flexed to 90 degrees and the forearm supinated to 5 degrees
What is it called when the radial head becomes dislocated?
Nursemaid’s elbow
What is the capsular pattern for the proximal radioulnar joint?
Equal limitation of supination and pronation
What is the resting position for the radioulnar joint?
35 degrees of supination and 70 degrees of elbow flexion
What is the closed packed position for the radioulnar joint?
5 degrees supination
What are the functions of the Medial Collateral (Ulnar) Ligament?
Supports the medial humeroulnar joint and form a tunnel with the FCU for the ulnar nerve
What are the functions of the Lateral Collateral (radial) Ligament?
- to maintain the humeroulnar and humeroradial joints when the elbow is loaded in supination
- stabilize the proximal radioulnar joint during full supination and pronation
What is the function of the annular ligament?
Checks displacement of the radial head
What forms the floor of the cubital tunnel?
medial collateral ligament
What forms the roof of the cubital tunnel?
aponeurosis, arcute ligament
What forms the anterior aspect of the cubital tunnel?
medial epicondyle
What forms the posterior aspect of the cubital tunnel?
medial head of the triceps
What forms the lateral aspect of the cubital tunnel?
olecranon
What travels through the cubital tunnel?
the ulnar nerve
When is the volume of the cubital tunnel the greatest?
when the elbow is in extension
Moving the elbow into full flexion decreases the size of the cubital tunnel volume by __%
55%
What is considered the entryway to the forearm?
The cubital fossa
What forms the lateral boundary of the cubital fossa?
Brachioradialis and ECRL muscles
What forms the medial boundary of the cubital fossa?
Pronator Teres muscle
What forms the proximal boundary of the cubital fossa?
imaginary line that passes through the humeral condyles
What forms the floor of the cubital fossa?
Brachialis muscle
What are the contents of the cubital fossa?
- Tendon of biceps brachii- Median nerve
- Brachial artery
- Radial nerve
- Median cubital or intermediate cubital cutaneous vein
Describe the concept of force couples of the elbow
In order for a movement to occur, muscles must balance each other out. For example, the triceps and biceps need to be balanced during elbow flexion/extension
Male carrying angle = - degreesFeale carrying angle = - degrees
5-10
10-15
A carrying angle greater than 15 degrees is considered cubitis ___.A carrying angle less than 5 degrees is considered cubitis ___.
valgus
varus
What is gunstock deformity?
an increase in cubital varus
If swelling occurs what position will the patient hold the hold in?
In the resting position, which is also position of maximum volume
The medial collateral ligament is placed on stretch by introducing a ____ force
valgus
The lateral collateral ligament is placed on stretch by introducing a ____ force
varus
Reflexes: Biceps = __ Brachioradialis = __ Triceps = __
C5
C6
C7