Post on 08-Jan-2017
The Shoulder Joint
Shoulder Joint
There are a number of articulations in the shoulder region
The glenohumeral joint is commonly called the shoulder joint
Other articulations include
• Acromioclavicular joint
• Sternoclavicular joint
Shoulder Joint
Sternoclavicular Joint
Sternoclavicular Joint
Shoulder Joint
Acromioclavicular Joint
Acromioclavicular Joint
Shoulder Joint
Glenohumeral Joint
Anterior View
Shoulder Joint
Glenohumeral Joint
Multiaxial
Synovial
Spheroidal
Anterior View
Shoulder Joint
Multiaxial
Synovial
Spheroidal
Posterior View
Shoulder Joint
Glenohumeral Joint
Formed by an articulation between
Scapula
Anterior View
Shoulder Joint
Glenohumeral Joint
Formed by an articulation between
Scapula and Humerus
Anterior View
Shoulder Joint
Articulation - Glenoid fossa of Scapula
Anterior View
Lateral View
Posterior View
Right side
Shoulder Joint
Articulation – Head of Proximal Humerus
Anterior View
Superior View
Posterior View
Right side
Shoulder Joint
The articulating bony surfaces are not congruent
The Glenohumeral joint is the most mobile joint in the body
The glenoid surface is relatively flat compared to the round head of the humerus
Right side
There are static stabilisers and dynamic stabilisers
In order to stabilise the joint and prevent it from dislocation there are a number of soft tissue structures that interact to stabilise the joint
Static Stabilisers
Lateral View
The Glenoid Fossa is flat and pear-shaped when viewed from its lateral
aspect
Lateral View
It is surrounded by a fibrocartilaginous rim of tissue,
the Glenoid Labrum, that deepens the cavity
Glenoid Glenoid
Labrum
Cross section through glenoid
Cross section through glenoid
+ labrum
The Glenohumeral joint is surrounded
by a capsule
The Glenohumeral joint is surrounded
by a capsule
There are three condensations
within the capsule that form ligaments
The Superior
Glenohumeral Ligament
The Middle
Glenohumeral Ligament
The Inferior
Glenohumeral Ligament
In different arm positions different ligaments tighten to stabilise the joint
As the arm is abducted, the inferior glenohumeral ligament becomes taut
In different arm positions different ligaments tighten to stabilise the joint
Dynamic Stabilisers
There are four rotator cuff muscles that surround the shoulder jointThese muscles move the arm, but are also very important in stabilising the shoulder joint
Subscapularis
Supraspinatus
Infraspinatus
Teres Minor
The Subscapularis muscle attaches to the Lesser Tuberosity of the Humerus
It arises from the whole of the ventral surface of the scapula
It internally rotates the arm
SubscapularisThe Shoulder
It arises from the
Supraspinous Fossa
Suprapinatus attaches to the upper part of the
Greater Tuberosity of the Humerus
It abducts the arm
It arises from the
Infraspinous Fossa
It externally rotates
the arm
Infraspinatus attaches to the posterior part of the
Greater Tuberosity of the Humerus
The Shoulder
The Humerus
Teres Minor attaches to the postero-inferior part of
the Greater Tuberosity of the Humerus
Posterior View
It arises from the
upper part of lateral
border of the scapula
It also externally
rotates the arm