JOINTS OF THE PECTORAL GIRDLE
- The pectoral girdle is also called the shoulder girdle .
The Sternoclavicular joint (SC):
→ Saddle-joint
- Formed between the manubrium of the sternum and the sternal end of the clavicle.
- Strengthened by several ligaments:
- 1. Anterior & posterior sternoclavicular joints.
- 2. Interclavicular ligament.
- 3. Costoclavicular ligament.
- Vascularized by the internal thoracic & the suprascapular arteries.
- Innervated by the branches of the suprascapular n.
- Provides limited movement, allowing the clavicle to rotate & elevate.
The Acromiclavicular joint (AC):
- Formed by the acromion of scapula & the acromial end of the clavicle.
- Is a plane-synovial joint.
- Ligaments:
- 1. Acromiclavicular ligament.
- 2. Coracoclavicular ligament
Glenohumeral joint :
- Formed between the glenoid fossa of the scapula & the head of the humerus.
- Is ball & socket synovial joint.
- Supported by loose fibers joint capsule & several ligaments:
- 1. The transverse humeral ligament.
- 2. The coracoacromial ligament.
- 3. Sup., inf., middle glenohumeral ligaments.
Allows a wide range of movements, including flexion, extension, abduction, adduction, internal & external rotation.
The Scapulothoracic joint:
(Is a physiological joint)
- Formed by the anterior surface of the scapula and the posterior thoracic cage.