Post on 21-May-2015
transcript
College of Allied Health Science
ANATOMY MUSCULOSKELETAL RADIUS & ULNA,
ELBOW AND RADIOULNAR JOINT
HERMIZAN BIN HALIHANAFIAH
Bsc Biomedicine (Hons) UKM
Ulna
Located on the medial aspect (the little
finger side) of the forearm.
Longer than radius.
At the proximal end is the olecranon,
forms the prominence of the elbow.
The coronoid process is an anterior
projection, together with the olecranon
receive the trochlea of the humerus.
Ulna
Anterior view
Trochlear notch
Olecranon
Radial notch
Coronoid process
Lateral view
Cont….
The trochlear notch is a large curved area between
the olecranon and coronoid process that forms part of
the elbow joint.
Just inferior to the coronoid process is the ulnar
tuberosity.
Distal end of the ulna consist of a head that is
separated from the wrist by a fibrocartilage disc.
A styloid process is on the posterior side of the distal
end.
Ulnar Tuberosity
Radius
Located on the lateral aspect (thumb side) of the
forearm.
Proximal end of the radius has a disc shaped head
that articulates with capitulum of the humerus and the
radial notch of the ulna.
Inferior to the head is the constricted neck.
A roughened area inferior to the neck on the medial
side, called the radial tuberosity, is a point attachment
for the tendons of the biceps brachii muscle.
Cont…
The shaft of the radius is widens distally to form a styloid process on the lateral side.
Ulnar Tuberosity
Radius and Ulna
Ulna and radius articulate with the humerus
at the elbow joint.
This articulation occur in 2 places; head of
radius articulate with capitulum of the
humerus, and trochlear notch of the ulna
articulates with trochlea of the humerus.
Elbow Joint
Cont….
Ulna and radius connect with one another at three
sites.
First, a broad, flat, fibrous connective tissue called
interosseous membrane joint the shaft of the two
bones.
This membrane also provide a site of attachment
for some tendons of deep muscles of the forearm.
Elbow Joint
Proximal Radioulnar Joint
Distal
Radioulnar Joint
Interosseous Membrane
Radiocarpal Joint
Cont…
Ulna and radius also articulates at their proximal
and distal end.
Proximally, the head of radius articulates with the
radial notch of ulna, depression that is lateral and
inferior to the trochlear notch of ulna.
This articulation is the proximal radioulnar joint.
Ulna and radius parallel each other
Radius cross over the ulna
Cont….
Distally, the head of the ulna articulates with ulna
notch of the radius.
This articulation is the distal radioulnar joint.
Finally, the distal end of the radius articulates
with three bones of the wrist, Lunate, Scaphoid
and the Triquetrum to form radiocarpal joint
(wrist joint).
Muscles of the Elbow
Muscles Move the Elbow Joint
Most of the muscles that move the radius and ulna
cause flexion and extension at elbow joint.
Is a hinge joint.
Muscles of the elbow can divide based on their
action:
– Flexion (flexor muscles)
– Extension (extensor muscles)
– Pronation (pronators muscles)
– Supination (supinators muscles)
Flexor Muscles
Biceps brachii
Brachialis
brachioradialis
Biceps brachii
Origin– Long head – supraglenoid tubercle of scapula.– Short head – coracoid process of scapula
Insertion – radial tuberosity of radius and bicipital aponeurosis
Action– Flexion forearm at elbow joint– Supinates forearm at radioulnar joint– Flexion arm at shoulder joint.
Nerve supply – musculocutaneous nerve
Long Head of Biceps
Short head ofBiceps
Brachialis
Origin – distal, anterior
surface of humerus
Insertion – ulnar tuberosity
and coronoid process of
ulna.
Action - Flexion forearm at
elbow joint
Nerve supply –
musculocutaneous nerve
Brachioradialis
Origin – lateral border of distal end of humerus.
Insertion – superior to styloid process of radius.
Action– Flexion forearm at elbow joint– Supination and pronation
forearm at radioulnar joint. (forearm in neutral position)
Nerve supply – radial nerve
Elbow Flexors
Extensor Muscles of Forearm
Triceps brachii
Anconeus
Triceps brachii
Origin
– Long head – infraglenoid tubercle of scapula
– Lateral head – lateral and posterior surface of
humerus superior to radial groove.
– Medial head – entire posterior surface of humerus
inferior to a radial groove.
Insertion – olecranon of ulna
Action
– Extension forearm
at elbow joint
– Extension arm at
shoulder joint
Nerve supply – radial
nerve
Anconeus
Origin – lateral epicondyle of humerus
Insertion – olecranon and superior portion of shaft of ulna.
Action - Extension forearm at elbow joint
Nerve supply – radial nerve
Triceps Brachii
Pronators Muscles of Forearm
Pronator teres
Pronator quadratus
Pronator teres
Origin – medial epicondyle of humerus and coracoid process of ulna
Insertion – midlateral surface of radius
Action- Pronates forearm at radioulnar joint , Weakly flexes forearm at elbow joint
Nerve supply – median nerve
Pronator quadratus
Orgin – distal portion of shaft of ulna
Insertion – distal portion of shaft of radius\
Action - Pronates forearm at radioulnar joint.
Nerve supply – median nerve
Supinator Muscle of Forearm
Supinator muscles Origin – lateral epicondyle of
humerus and ridge near radial notch of ulna (supinator crest)
Insertion – lateral surface of proximal one-third of radius.
Action - Supinates forearm at radioulnar joints.
Nerve supply – deep radial nerve
Muscles of the Forearm Move the Wrist, Hand, Thumb and Fingers
Group of muscles that act on the digits are
known as extrinsic hand muscles because
originate outside the hand and insert within it.
There is 2 groups of forearm muscles:
– Anterior compartment (flexor muscles)
– Posterior compartment (extensor muscles)
Anterior view of forearm muscles
Anterior compartment of Forearm Muscles
Muscle of the forearm originate on the humerus
Insert on the carpals, metarcarpals, and phalanges
Act as flexor Divide into superficial or deep muscles.
Posterior compartment of Forearm Muscles
Muscle of the forearm originate on the humerus
Insert on the carpals, metarcarpals, and phalanges
Act as extensor Divide into superficial or deep muscles.
Forearm Muscles
Superficial anterior compartment muscles
Deep anterior compartment muscles
Superficial posterior compartment
muscles
Deep posterior compartment muscles
Superficial Anterior Compartment Muscles
Arrange in following order from lateral to medial:
1. Flexor carpi radialis
2. Palmaris longus
3. Flexor carpi ulnaris
4. Flexor digitorum superficialis – deep to the other 3 muscles and is a largest superficial muscle in the forearm.
Deep Anterior Compartment Muscles
Arrange in following order from lateral to medial:
1. Flexor pollicis longus
2. Flexor digitorum profundus
Superficial Posterior Compartment Muscles
Arrange in following order from lateral to
medial:
1. Extensor carpi radialis longus
2. Extensor carpi radialis brevis
3. Extensor digitorum
4. Extensor digiti minimi
5. Extensor carpi ulnaris
Deep Posterior Compartment Muscles
Arrange in following order from lateral to
medial:
1. Abductor pollicis longus
2. Extensor pollicis brevis
3. Extensor pollicis longus
4. Extensor indicis
Elbow Joint
Ulna and radius articulates with the humerus Occurs in 2 place Head of radius articulates with capitulum of
the humerus , and Trochlea of the humerus articulates with
trochlear notch of the ulna.
Elbow Joint
Head of Radius
Trochlear notch
Olecranon
Coronoid Process
Radio-Ulnar Joint (Pivot Joint)
Radius and ulna also articulates with one another in 2 places.
Proximally the head of radius articulates with the radial notch of ulna, a depression that is lateral and inferior to the trochlear notch.
This articulation called proximal radioulnar joint.
Head of radius retain contact with radial notch of ulna by annular ligament.
Distally the head of ulna articulates with ulna notch of the radius.
This articulation is the distal radioulnar joint. the distal end of radius bone articulates with
three bones of the wrist; lunate, scaphoid and the triquetrum to form radiocarpal join.
Radio-Ulnar Joint (Pivot Joint)
Proximal Radio-Ulnar Joint
Head of radius articulate with radial notch of ulna.
Annular Ligament
Distal Radio-Ulnar Joint
Head of ulna articulate with ulnar notch of radius.
Elbow Joint
Hinge joint (one way direction) Articulations between the trochlea of the
humerus with the trochlea notch of ulna and The capitulum of the humerus with the head
of the radius comprise the joint. Movements – flexion and extension of the
forearm
Anatomical Components of Elbow joint
Articular capsule– Consist 2 parts; anterior and posterior parts– Anterior part – covers anterior part of the joint,
from radial and coronoid fossa of the humerus to the coronoid process of the ulna and annular ligament of the radius.
– Posterior part – from capitulum, olecranon fossa, and lateral epicondyle of the humerus to the annular ligament of the radius, olecranon process of ulna and posterior to the radial notch.
Ulnar Collateral Ligament– Thick– Triangular– Extends from the medial epicondyle of the
humerus to the coronoid process and olecranon of the ulna.
Radial Collateral Ligament– Strong– Triangular– Extends from lateral epicondyle of the humerus to
the annular ligaments of the radius and the radial notch of the ulna.
Common Injuries Associated With Elbow
Tennis elbow / Lateral epicondylitis Compression of the ulnar nerve Olecranon bursitis / student’s elbow Golfers / Throwers Elbow (Medial
Epicondylitis) Elbow dislocation
Cubital Fossa
Cubital Fossa
Region of the upper limb in front of the elbow joint
Triangular area with the following boundaries: – laterally, brachioradialis muscle – medially, pronator teres muscle – superiorly, an imaginary line from the medial and
lateral epicondyles.
Cubital Fossa
Bicipital Aponeurosis
Median Nerve
Pronator TeresBrachioradialis
Brachial Artery
Biceps Brachii Tendon
Venous Layer
1 - cephalic vein 2 - basilic vein 3 - median cubital vein
1- bicipital aponeurosis (Grace of God tendon – protect median nerve and brachial artery)
2- biceps tendon
Aponeurotic layer
Artery Nerve Layer
1 - brachial artery 2 - median nerve
Muscular Floor
1 - supinator 2 - brachialis 3 - biceps tendon
Bony Floor
1 - humerus 2 - radius 3 - ulna
Clinical Importance
Phlebotomy – venous blood drainage from median cubital vein
Blood pressure measurement - stethoscope is placed over the brachial artery in the cubital fossa. The brachial pulse may be palpated in the cubital fossa.
Cubital Fossa