4) Osteology Myology Arthrology Elbow+superior ulnar joint Flashcards
Classification elbow joint
True hinge, synovial,compound, uniaxail
What is the sub divisions of the elbow articulations
The elbow joint can be sub-divided into:
1) humero-ulnar
2) humero-radial articulation.
The radioulnar joint plays no part in the movements of the elbow joint.
Articulating surfaces elbow
See file
Fibrous capsule
See file
Synovial membrane
The synovial membrane lines the internal surface of the fibrous capsule attaching to the articular margins of the humerus and ulna.
It is reflected upwards to cover the coronoid and radial fossae anteriorly and the olecranon fossa posteriorly.
Distally, the synovial membrane continues into the superior radioulnar joint, where it covers the inferior part of the annular ligament and is also reflected on to the neck of the radius.
Extensive forming numerous synovial folds
Ulna collateral ligament
Pinky side
🔺Thick ant+post bands thinner intermediateband
> Anterior band: front of medial epicondyle to medial coronoid process
> Intermediate band: undersurface medial epicondyle blends transverse band
> Posterior band: back of medial epicondyle to medial olecranon
Radial collateral ligament
Thumb side
Strong 🔺band
Less distinct than ulna ligament
Lateral epicondyle blends with the annular ligament— radial notch
Passes forwards and backwards
Flexion
NROM limiting factors
0-145°
90= most stable position
Anterior muscles of arm and forearm
Posterior joint capsule
Opposing muscles – triceps
Extension
NROM limiting factors
0°
Anterior fibrous capsule
Opposing muscles – biceps
Radio and ulnar collateral ligaments anterior part
What is the carrying angle
When your arms are held out at your sides and your palms are facing forward, your forearm and hands should normally be about 5 to 15 degrees away from your body. This is the normal “carrying angle” of the elbow. This angle allows your forearms to clear your hips when you swing your arms, such as during walking
Women 20-25
Superior radialulnar joint
Pivot, Simple,Synovial,Uniaxail
Circumference radial head+
fibro-osseous ring radial notch of ulna and annular ligament
Articular surface
See file
Quadrate ligament
Lower radial notch ulna to adjacent medial surface neck of radius
Criss-cross manner between radius and ulna
Some fibres are always under tension
Boarders are strengthened by lower annular ligament
NROM and limiting factors
Pronation
0-80
Quadrate ligament
NROM and limiting factors
Supination
0-70
Passive resistance of opposing muscles
Quadrate ligament
How does movements occur
Movement cannot occur unless there is simultaneous movement at the inferior radialular joint
Stability
Quadrate ligament
Children: head of radius pulled from annular ligament = traction dislocation
Muscles of the forearm
Supinator - supination forearm
Biceps brachii -flexor elbow, supinator forearm=lost when elbow is fully healed extended
Brachialis -main elbow flexor
Brachioradialis -flexes elbow *midpronation/supination
Pronator teres -anteromedial movement lower end radius weak flexor
Pronator quadratus - initiates pronation
Triceps -Extend elbow. Long head adduct and extend from from flexed
position
Anconeus -extension elbow joint, abduction ulna
Supinator
S: y shaped 🔺
O:
1)Humeral Head
Inferior aspect of lateral epicondyle of humerus Radial collateral ligament
2)Annular ligament
Ulnar Head
Supinator crest Fossa of ulna
I:Posterior, lateral and anterior aspects of the radius
D:Downwards and laterally wrapping around the proximal third of the radius
A: Supination of the forearm
However, if a powerful supinatory activity is performed then Biceps brachii becomes the prime mover (with the elbow positioned in 120 ̊ semi-flexion to allow this to occur)
NS:Posterior radial interosseous nerve (C5,6)
[which is the deep branch of the Radial nerve]
Bicepes brachii
S: long strap like
O:
1) long head: supraglenoid tubercle sits in bicipital groove
(synovial sheath)
2) Apex coracoid process
I: 2 tendons fuse forming 1 twisting 90° posterior part radial tuberosity
A: flexor elbow, supinator forearm=lost when elbow is fully healed extended
F: opening twisted lid of bottle
NS: musculocutaneous nerve C5,6
Brachialis
S: long strap like
Main flexor of arm
O: distal 2/3 anterior surface humerus +adjacent septa
I: inferior coronoid process and tuberosity of ulna
A: main flexor elbow. Controls extension produced by gravity
F: lowering down something fragile
NS: musculocutaneous nerve C5,6
Brachioradialis
S:
Powerful flexor of forearm in mid-position
O: upper 2/3 anterior lateral supracondylar ridge of humerus and adjacent septa
I: lateral surface of styloid process radius
A: flexes elbow *midpronation/supination
F: eccentrically as extensor = hammering
NS: radial nerve C5,6
Pronator teres
S:
O:
1)humeral head: common flexor origin, medial epicondyle of humerus
2)Ulnar head:pronator ridge ulna
I: middle lateral surface radius
A: anteromedial movement lower end radius weak flexor
F:
NS: median nerve C6,7
Pronator quadratus
S:
O: lower 1/4 anterior surface ulna
I: lower 1/4 anterior surface radius
A: initiates pronation
F:
NS: anterior Interosseous branch median nerve C8,T1
Tricepes
S:
O:
1) long head: infraglenoid tubercle of scapula and adjacent glenoid labrum
2) medial head: posteriorsurface of humerus (below+ medial spiral groove) adjacent septa
3) lateral head: posterior surface humerus (above+lateral spiral groove)
I: posterior surface olecranon and adjacent deep fascia of forearm
A: Extend elbow. Long head adduct and extend from from flexed position
F: pushing up from chair press-ups
NS: radial nerve C6,7,8
Anconeus
S:
O: posterior surface lateral epicondyle
I: lateral surface of olecranon, upper 1/4 posterior surface ulna
A: extension elbow joint, abduction ulna
F: screwdriver opening nail polish
NS: radial nerve C7,8
How do these muscles contribute to stability of the elbow and superior radioulnar joints?
?
Superior radioulnar joint
Joint capsule
Same as elbow
Superior radioulnar joint
Synovial membrane
Elbow part of joint space
Attachments:
Upper margin fibrocartilage lining annular ligament and lower part extending below ligament as a redundant fold loose attachment head of radius. Accommodates twisting
Upper surface quadrate ligament = limits + supports it. Medially to radial notch
Superior radioulnar joint
Movements
Rotation head of radius within fibro-osseous ring of annular ligament and radial notch
- Rotation of superior concave surface of Radial head in relation to capitulum
- Gliding bevelled ridge of radial head against capitultrochlear groove
- Lateral displacement radial head
- Tilting of plane of radial head inferolaterally
Annular ligament
Attachments
Anteroposterior margins of radial notch forming 4/5 of the articular surface of the superior radioulnar joint
Fits round radius narrower distally to keep radius in place
Functions of the annular argument
1) Flexible fibrocartilaginous ring forming 4/5 of the fibro osseous articular surface of superior radioulnar joint
2) Facilitating the range of movement of pronation and supinnation made of fibrocartilage allowing friction free movement
3) important static stabiliser by cupping the radial head and preventing downward displacement of radial head during distraction forces due to its narrower inferior diameter
