Gleno-humeral joint
Known to be the main joint of the shoulder joint. This is formed by an articulation between the Humerus (arm bone) and part of the articulaitng surface of the Scapula called the Glenoid Fossa
Acromio-clavicular (AC) joint
This joint is at the top of the shoulder joint. It is formed between the Acromion (articulating surface of the Scapula) and Clavicle
Sterno-clavicular (SC) joint
This is one of the 4 joints associated with the Shoulder. It is formed between the Clavicle and part o the Sternum called the Manubrium.
Scapulo-thoracic articulation
This is not a true joint and is known to be an articulation between the Thorax (Ribs) and Scapula. This joint is dependant on the integrity of the AC and SC joint
BONES AND JOINTS OF THE SHOULDER
LIGAMENTS OF THE SHOULDER
Gleno-humeral ligament
This is the name given to the main group of 3 stabilising ligaments (superior, middle and inferior) between the Humerus and Glenoid Fossa.
Coraco-humeral ligament
This ligament is found between the Corocoid process of the Scapula and Humerus
Transverse humeral ligament
Also known as Brodie's Ligament, it is found over the top of the bicipital groove on the Humerus which job is to encases the long head of the Biceps tendon within the groove.
Coraco-clavicular ligament
This comprises of two ligaments (the Trapezoid and conoid ligament). These are found in between the Coracoid process of the Scapula and Clavicle.
Acromio-Clavicular ligament
This ligament has a superior and inferior part between the Acromion and Clavicle. Working with the Coraco-clavicular ligaments they stabilize the Clavicle and Scapula but can be the sight of injury after traumatic falls.
Coraco-acromial ligament
This ligament is found between the Coracoid process and Acromion, It protects the superior surface of the Humeral head and supports the Glenohumeral joint
BURSA OF THE SHOULDER
Subacromial-Subdeltoid bursa
It extends below the Acromion and over the humeral head. The Bursa also travels over the Supraspinatus and Infraspinatus tendon. The Subacrominal bursa is a common site of bursitis causing impingement of the shoulder.
Supra-acromial bursa
This is located above the Acromion. It is not normally involved in Impingement syndrome due to the position of it
Subcoracoid bursa
This is found inferiorly to the Coracoid process. It function is to reduce friction between the tendons of the shoulder joint.
Subscapular bursa
Located between the Subscapularis and joint capsule it prevents the Subscapularis tendon becoming irritated on shoulder movement
There are other Bursa found in the shoulder which are less commonly injuried.
MOVEMENTS OF THE SHOULDER
Shoulder Abduction
This is movement of the arm upwards in a sideways motion away from the bodies centre line.
The muscles involved in this movement are the Deltoid and Supraspinatus.
Shoulder Adduction
This is the sideways movement of the arm back down to the side inline to the bodies centre line.
The muscles responsible for this movement are
Subscapularis
Pectoralis Major
Latissimus Dorsi
Teres Major
Shoulder Flexion
This is the movement of the arm upwards in a forward motion to above the head.
The muscles involved in this movement are the Anterior fibres of the Deltoid, Pectoralis Major, Coraco-brachialis and Biceps
Shoulder extension
This movement takes the arm backwards lifting it behind the body.
The muscles involved in this movement are the posterior fibres of the Deltoid, Latissimus Dorsi, Teres Major and Triceps