Shoulder and Elbow Anatomy
Sarah Rayner Extended Scope
Practitioner Physiotherapist
Dr Tim Hughes GPSI
MSK Orthopaedic Services
Surface Anatomy
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Shoulder
– Acromion (lateral border, post angle, ant edge)
– AC joint line
– Coracoid
– Greater and lesser tuberosities
– Insertions of supraspinatus, infraspinatus and suscapularis
– Identify muscle bellies of supraspinatus, infraspinatus and teres minor
– Outline of the scapula
– C4 and C5 dermatomes
Elbow
– Head of the radius
– Radio-humeral joint line
– Ulner, median and radial nerve innervation of the skin
– Lateral and medial epicondyles and common flexor and extensor origins
– Insertion of biceps
– C5/6 and 7 dermatomes
Shoulder Anatomy
With its 5 joints, 8 ligaments and 30 muscles,
the shoulder complex presents a compromise
between stability and mobility, and the result
is that it is inherently unstable.
Biomechanics of shoulder
elevation
• Humerus rotates about the
scapula at the GH joint, the
scapula rotates about the clavicle
at the AC joint and the clavicle
rotates about the sternum at the
SC joint.
• Normal movement required at all
joints for full elevation to occur –
efficient scapulo-humeral rhythm
(Codman 1934).
• Ratio GH to scapula movement
2:1
Shoulder Muscles
• Scapula Pivoters – (Trapezius, Serratus ant,
Rhomboids, lev scap)
• Glenohumeral protectors – (RC & LHB)
• Humeral positioners – (deltoid)
• Power Drivers (Teres major, pec major and lat
dorsi)
Rotator Cuff
Shoulder Summary
• Shoulder complex movement occurs through the GHJ,
ACJ, SCJ and scapula-thoracic gliding mechanism.
• Anatomical structures and neural mechanisms control the
Shoulder complex allowing smooth synchronised pain
free movement.
• Shoulder function is significantly dependent on normal
biomechanics.
• Failure of any component may lead to abnormal function
of the shoulder complex.
• Understanding biomechanics – successful assessment and
treatment planning.
Elbow Anatomy