Shoulder Flashcards
(46 cards)
What are the shoulder movements?
Extension, flexion, abduction, adduction, medial rotation, lateral rotation, circumduction
What is the characteristic of the acromion variation according to Bigliani?
Acromion has a hook shape
How does the glenoid fossa affect mobility and instability?
It is highly unstable which creates high mobility
What role does the labrum play in the glenoid fossa?
Increases stability
What are the characteristics of the plane of the scapula?
Superior aspect is 30-45° anterior to frontal plane, slight anterior inclination, upward rotation in frontal plane
Is arm elevation easier when the scapula is in its plane or out of plane?
Easier when scapula is in its plane
Under which type of shoulder rotation is arm elevation easier?
Under external shoulder rotation
Why is elevation easier with external shoulder rotation?
The greater tubercle can clear the acromion process and acromioclavicular ligaments
What are the joints of the shoulder?
- Acromioclavicular joint
- Glenohumeral joint
- Scapulothoracic joint
- Sternoclavicular joint
What are the characteristics of the acromioclavicular joint?
3 rotatory motions and 3 translatory motions
What are the ligaments of the acromioclavicular joint?
- Coracoclavicular (trapezoid and conoid)
- Acromioclavicular
What does the trapezoid ligament do?
Prevents medial movement of acromion process relative to clavicle
What does the conoid ligament do?
Restricts upward rotation of scapula and pulls clavicle in upward rotation
What are the grades of acromioclavicular joint injuries?
- Grade I: AC ligament stretched partially torn
- Grade II: AC ligament completely torn
- Grade III: AC joint separation
What are the rotary motions of the sternoclavicular joint?
- Elevation/depression
- Protraction/retraction
- Upward/downward rotation
What are the ligaments of the sternoclavicular joint?
- Anterior/posterior sternoclavicular
- Interclavicular
- Costoclavicular
- Intraarticular disc
What is the scapulothoracic joint?
Not a real joint with no true articulations
What are the functions of the scapulothoracic joint?
- Increase ROM of shoulder
- Enhance reach
- Maintain favourable length-tension relationship for deltoid
- Maintain G-H stability
- Shock absorption
- Permits elevation of body
What is the glenohumeral joint type?
Ball and socket
What is the scapulohumeral rhythm?
2:1 GH:ST; for every 2° of GH movement there is 1° of ST movement
What are the contributions of shoulder joints to 180° of arm elevation?
- GH = 120° abduction
- ST = 60° upward rotation
- SC = 30° elevation and posterior rotation
- AC = 30° upward rotation
What elements are responsible for static glenohumeral stability?
- Coracohumeral ligament
- Glenohumeral ligament
- Labrum
- Capsule
- Joint contact
- Scapular inclination
- Intraarticular pressure
What elements are responsible for dynamic glenohumeral stability?
- Rotator cuff muscles
- Biceps
- Deltoid
How is shoulder instability classified?
- Etiology: traumatic vs atraumatic
- Degree of instability: subluxation vs dislocation
- Unidirectional vs multidirectional
- Generalized ligamentous laxity