Elbow Flashcards
Elbow
title
Rotator cuff revision
- Supraspinatus
- Abduction
- Subscapularis
- Medial rotation
- Infraspinatus
- Lateral rotation
- Teres minor
- Lateral rotation
Arthrokinematics of the glenohumeral joint
For Abduction/Adduction and
medial/lateral rotation
* Roll in the direction of the
movement
* Slide in the opposite direction
For pure flexion/extension
* Spin around the axis
perpendicular to the joint
Control of arthrokinematics
The rotator cuff’s main role is to
provide the fine tuning of the
GHJ movement to keep the
humeral head centrally located in
the glenoid fossa
Force couple during elevation
So as we raise our arm up into
abduction…
* Deltoid’s pull is upwards, helping
the roll but superiorly displacing
the humeral head
* Supraspinatus’ pull is medial,
helping the roll but without
superior displacement
* Subscapularis, infraspinatus and
teres minor’s pulls are
inferomedial, creating the slide to
prevent the superior displacement
Joints of elbow and forearm
Movements distributed across
four joints
* Humeroulnar joint
* Humeroradial joint
* Proximal radioulnar joint
* Distal radioulnar joint
Therefore can be stable in a wide
range of positions
Elbow joint complex
Humeroulnar joint
* Between Trochlea of humerus
and Trochlear notch of ulnar
* Hinge joint
Humeroradial joint
* Between Capitulum of
humerus and Fovea of radius
* Pivot joint – a bit like a mini
ball & socket
CRAzy TULips
Capitulum – RAdius
Trochlea - ULnar
Radioulnar joints
Both pivot joints that allow the
radius to rotate around the ulnar for
supination and pronation
Proximal = Radial head and radial
notch of the ulna
Distal = Ulnar head and ulnar notch
of the radius
Forearm action of elbow flexors
Biceps is an elbow flexor and
forearm supinator due to
it’s insertion on the radius
Levers at the elbow
quiz
Tricep kickbacks
Open or closed chain?
What class of lever?
open
3rd class lever
Tricep dips
Open or closed chain?
What class of lever
closed
1st class lever
whats are the palpable bony landmarks of the elbow
Medial epicondyle - medial projection of the humerus. Lateral epicondyle - lateral projection of the humerus. Radial head - trace the lateral arm distally to proximally, palpating where the radial head articulates with the humerus.
Describe the articulating surface of the humerus
Modified condyle
The articular part of the humerus is a modified condyle and is wider transversely. It articulates with both the ulna and radius and consists of a medial trochlea and a lateral capitulum, which are separated by a faint groove.
describe the articulating surface of the ulna
The articular surface of the ulna is involved in the proximal radioulnar joint and the distal radio-ulnar joint.
The articular surface of the proximal radioulnar joint is formed by the head of radius and the radial fossa of ulna, both of which are lined with hyaline cartilage.
The head of ulna has a convex articular surface on its lateral side to articulate with the ulnar notch of radius.
The ulna also has a wrench-shaped trochlear notch that articulates with the trochlea of the humerus.
describe the articulating surface of the radius
The radius is a bone in the forearm that articulates with the humerus, the ulna, and the carpal bones.
The proximal end of the radius has a head that articulates with the capitulum of the humerus at the elbow joint, and with the radial notch of the ulna at the proximal radioulnar joint.
The distal end of the radius articulates with the carpal bones at the wrist joint, which is a condyloid-type synovial joint.
elbow and radioulnar joints
The elbow joint is classified structurally as a synovial joint. It is also classified structurally as a compound joint, as there are two articulations in the joint. Synovial joints, also called diarthroses, are free movable joints. The articular surfaces of the bones at these joints are separated from each other by a layer of hyaline cartilage. Smooth movement at these joints is provided by a highly viscous synovial fluid, which acts as a lubricant.
A fibrous capsule encloses the joint, and is lined internally by a synovial membrane. Synovial joints can be further categorized based on function. The elbow joint is functionally a hinge joint, allowing movement in only one plane (uniaxial).
ligaments providing stability to the elbow joint
two collateral ligaments: the medial collateral ligament (MCL, also known as ulnar collateral ligament, or UCL) and the lateral collateral ligament (LCL).
Annular Ligament of radius
radial collateral ligament
ulnar collateral ligament
Quadrate ligament
Flexion and Extension
heading
Flexors
Biceps brachii,
brachialis
brachioradialis
biceps brachii
Origin: Supraglenoid tubercle of scapula and apex of coracoid process of scapula.
Insertion: Radial tuberosity and antebrachial fascia.
Action: Supinates forearm; flexes forearm at elbow joint, most effectively when the forearm is supinated.
Innervation: Musculocutaneous nerve (C5-C6).
brachialis
Origin: Anterior aspect of distal half of humerus.
Insertion: Coronoid process and tuberosity of ulna.
Action: Flexes forearm at elbow joint.
Innervation: Musculocutaneous (C5-C6) and radial (C7) nerves.
brachioradialis
Origin: Superior two thirds of lateral supracondylar ridge of humerus.
Insertion: Lateral aspect of distal part of radius.
Action: Flexes forearm at elbow joint.
Innervation: Radial nerve (C5-C6).
