shoulder anatomy. information for patients
TRANSCRIPT
Shoulder Anatomy.Information for patients.
Dr Geoffrey SmithImages courtesy of www.biodigital.com
Bones
• The shoulder (glenohumeral joint) is a ball and socket joint.
• The ball is at the top of the arm bone (the humerus).
• The socket is the glenoid which is part of the shoulder blade (scapula).
Humerus Scapula
Soft tissue
• The glenohumeral joint is surrounded by a sleeve of tissue (the capsule).
• The capsule is thick in places & forms ligaments.
Capsule
Tendons
• Outside the capsule are the tendons of the rotator cuff.
• Tendons are where muscles attach to bone.
• Muscle pulling on bones through tendons produces movement at joints.
Rotator Cuff
• The rotator cuff is composed of 4 tendons
• Subscapularis (at the front)
• Supraspinatus and infraspinatus (at the top)
• Teres minor (at the back).
Subscapularis
Supraspinatus
Infraspinatus
Teres Minor
Subacromial space
• Above the rotator cuff is the acromion which is the bone you can feel on the top of your shoulder.
• The acromion is part of the shoulder blade (scapula).
• The subacromial space is between the undersurface of the acromion and the upper surface of the rotator cuff.
• The subdeltoid or subacromial bursa (a sac of fluid) occupies the subacromial space.
Acromion
Subacromial bursa
Clavicle and AC joint
• At the front of the shoulder the acromion articulates with the collar bone (clavicle) at the acromioclavicular joint (ACJ)
• The ACJ is stabilised by the ACJ capsule and the coracoclavicular ligaments
Clavicle
Acromion AC joint
CoracoclavicularLigaments
ACJ capsule
Biceps tendon
• The biceps muscle (the strong muscle at the front of the arm) has two tendons.
• One (long head or LHB) is attached to the top of socket of the shoulder joint.
• The second tendon is attached to the coracoid process (part of the scapula). This is a finger-like projection of bone that you can feel about 4 cm below the outer part of your collar bone.
• The two tendons join together to form the biceps muscle at the top of the arm
LHB
Coracoid process
Biceps Muscle