Shoulder girdle - Joints and Ligaments Flashcards
What are the three joints in the shoulder girdle?
The sternoclavicular (SC) joint
The Acromioclavicular (AC) joint
The Glenohumeral (GH) joint
What type of joint is the SC joint
It is a saddle joint, but functions like a ball & socket joint
The articular disc is made of fibrocartilage, its a shock absorber,
Fracture is common.
/What type of joint is the AC joint?
Its a plane type of synovial joint
Where is the location of the GH joint and what type of joint is it?
It articulates at the glenoid fossa and humeral head.
It’s a ball and socket joint.
What joint relies heavily on the rotator cuff for stability?
The glenohumeral joint
What is considered another joint, but isnt actually technically a joint. Describe some of its features.
The scapulthoraic joint, there are no articulating bone surfaces or ligaments.
Its essential for movement of SC, AC, GH and the upper limb as a whole.
What movements are available at the SC joint?
Protraction/retraction
Elevation/depression
rotation about the longitudinal axis
What is the nerve supply?
Medial supraclavicular nerve
Nerve to subclavius
What are the ligaments of the AC joint?
The acromioclavicular ligament (weak)
The coracolavicular (very, very strong) holds the scap up onto the clavicle
Coracoarcominal ligament - b/w coracoid process and acromion.
What are the movements of the AC joint?
It glides on the acromial end of the clavicle as the scap moves on the thoracic cage.
What is the nerve supply of the AC joint?
Lateral supraclavicular nerve
Laterl pectoral nerve
Axillary nerve
What are the ligaments of the GH joint?
The Transverse humeral ligament (holds bicep in place over greater and lesser tubercle)
Coracohumeral ligament (b/w coracoid and greater tubercle)
Coracoacromial ligament (prevents superior displacement, b/w coracoid process and acromion)
They all reinforce the joint anteriorly.
What are the movements of the GH joint?
Flexion/extension
Abduction/adduction
Internal/external rotation
Circumduction
What is the bursa of the GH joint?
A synovial membrane sac, prevents friction between musculoskeletal structures.
Can become acute or chronically inflamed.
What is the glenoid labrum?
Its a fibrocartilaginous ring-like structure lining the outer rim of the glenoid fossa.
Function: increase stability by:
- increasing depth
- Maintain negative pressure
- providing insertion
