Pectoral Girdle anatomy and ligaments PDF

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Summary

Anatomy and ligaments (attachments) of the Shoulder Girdle...

Description

Pectoral Girdle Consists of your; -

Shoulder blades (scapula) Collar bones (clavicles)

The pectoral girdle serves as an attachment site for the muscles of the upper back, chest and neck. Bones attached to the pectoral girdle include the upper arm (humerus) and breastbone (sternum). 3 main joints 1. Scapulothoracic joint = (Not a real synovial joint but a sliding joint) Between the scapula and ribs 2-7. The scapula and the ribs are not in the direct contact but rather the muscles of the chest wall and the muscles under the scapula slide against each other. When moved, it also causes a movement at either AC or SC joint. 2. Acromioclavicular joint = (Synovial plane/ Sliding joint) Connects the acromion of the scapula and the clavicle. Ligaments hold it together. It’s joint capsule is thin and weak. Features - Loose fibrous capsule. 3. Sternoclavicular joint = (plane style synovial joint with an articulate disc) Connects the sternum and the clavicle articulate. It has ligaments that attach the bones together. Features – Strong fibrous capsule

Clavicle

Scapula

The Ligaments of the Pectoral Girdle Ligaments around the sternoclavicular joint 1. Anterior (Retraction) and posterior (Protraction) sternoclavicular ligaments = Sternum – Clavicle (Depression) 2. Interclavicle ligament = Clavicle - Clavicle (Depression) 3. Anterior (Retraction) and posterior (Protraction) Costoclavicular ligament = Clavicle – 1st rib and Costal cartilage (Elevation)

Articular disk (Depression)

Ligaments around the acromioclavicular joint

Inferior sternoclavicular joint capsule

The Coracoclavicular ligament = Coracoid process of the scapula - Clavicle. This combined ligament is the main support for the AC joint while moving horizontally. - Conoid ligament = Medial side - Trapezoid ligament = Lateral side 2. The Acromioclavicular ligament = Acromion of the scapula - Clavicle. Is here to support the joint capsule. 3. Coraco-acromial ligament = Acromion of scapula – Coracoid process of scapula. 1....