Joints Flashcards
what are the 3 joints that make up the elbow?
- humeroradial joint
- humeroulnar joint
- radioulnar joint
what is the articulation of the humeroradial joint?
capitulum of humerus + head of radius
what are the degrees of freedom (movement) of the humeroradial joint?
flexion, extension, pronation, supination
what ligament attaches the humeroradial joint?
radial collateral ligament
description of radial collateral ligament?
what happens if it is torn?
fan like, strong
extends from lateral epicondyle of humerus
if torn: arm adducts uncontrollably
tennis elbow: inflammation of this ligament
what is the articulation of the humeroulnar joint?
trochlea of the humerus and the trochlear notch of the ulna
what are the degrees of freedom (movement) of the humeroulnar joint?
flexion + extension
what ligament attaches the humeroulnar joint?
medial ulnar collateral ligament
description of medial ulnar ligament?
what happens if it is torn?
has 3 bands:
- anterior cord-like band (strongest)
- posterior fan-like band (weakest)
- oblique band
if torn: abnormal abduction
what is the articulation of the radioulnar joint?
head of radius, radial notch of ulna
what are the degrees of freedom (movement) of the radioulnar joint?
pronation + supination
what ligaments attach the radioulnar joint?
- anular ligament
2. oblique cord of interosseus membrane
how is the anular liigament injured?
pulled elbow: head of radius escaped from this lig.
Occurs mostly in children bc lig isn’t fully developed
how stable is the elbow joint?
how is it usually damaged in adults?
Very stable + strong, dislocation usually due to fractures
Fracturing olecranon affects trochlear notch + elbow joint
what is the articulation of the AC joint?
what is the articulation covered by?
acromium process of the arcomion and the acromial end of the clavicle
articulating surfaces are covered by fibrocartilage and are separated by wedge-shaped articular disc
what is the degrees of freedom (movement) of the AC joint?
sliding and accomodatory movements from articulation of clavicle with sternum + movement of scalpula
what are the ligaments of the AC joint?
- acromiclavicular ligament
2. coracoclavicular ligament (trapezoid + coracoid separated by bursa)
what occurs when acromioclavicular ligament is damaged?
what is an example of this?
acromioclavicular subluxation aka shoulder separation: damage to this lig during downward displacement of the clavicle
ex: high school football player tackling with shoulder
What is the articulation of the glenohumeral joint?
glenoid foss or glenoid cavity of scapula and head of humerus
what are the degrees of freedom (movement) of the glenohumeral joint?
external + internal rotation, flexion + extension, adduction + abduction
lots of movement making it unstable
what is a carrying angle?
angle of fully extended ulna with long axis of humerus
more pronounced in women to clear hips
what is the nerve supply to the elbow?
musculocutaneous, radial + ulnar nerve
what are the bursae of the elbow?
- Intratendinous olecranon bursae (in tendon of triceps)
- subtendinous olecranon bursae
- subcutaneous olecranon bursae
- non olecranon: bicipitoradial bursae
what are the muscles of the elbow?
brachialis
biceps brachii
triceps brachii
what kind of joint is the elbow?
synovial joint
What type of joint is the AC joint?
plane joint
what is the nerve supply of the AC joint?
lateral pectoral and axillary nerves
also cutaneous lateral supraclavicular nerve
what kind of joint is the glenohumeral joint?
ball and socket synovial joint
what covers the glenohumeral joint?
hyaline cartilage1
what muscles surround this joint?
rotator cuff muscles…
1) Supraspinatus
2) Infraspinatus
3) teres minor
4) subscapularis
biceps brachii weakly
hold head of humerus in scapula
what ligaments hold the glenohumeral joint together?
- Glenohumeral Ligaments
- Coracohumeral Ligament
- Transverse Humeral Ligament
- coracoacromial arch
what are the muscles of the glenohumeral joint?
scapulohumeral muscles
Axio appendicular muscles act indirectly
what is the innervation of the glenohumeral joint?
Suprascapular, axillary and lateral pectoral nerves
what is the bursae of the glenohumeral joint?
- Subtendinous Bursa of Subscapularis (protects subscalpularis tendon)
- Subacromial Bursa (helps supraspinatus tendon move)
How does injury to SITS muscles occur?
often happens to pitchers, head of humerus pops out
how does subacromial bursitis occur?
calcium deposits
normally found alongside supraspinatus tendonitis
what are the ways the shoulder can become dislocated?
what are the complications?
- anterior dislocation: head of humerus pops out inferior to coracoid process
• Complications: axillary nerve ruptured, affecting deltoid + teres minor. Wont be able to abduct arm fully (only 15 degrees). - posterior dislocation: Very rare
• Complications: none bc no nerves
