Posterior Shoulder Region
Posterior Shoulder Region
is composed of a series of muscles that surround the scapula
Posterior Shoulder Region
is composed of a series of muscles that surround the scapula
The superficial muscles are
Trapezius
Trapezius
Originates from the midline from the skull, cervical and thoracic vertebrae
Inserts onto the spine of scapula and clavicle
It rotates and controls the scapula
Superficial muscles
Trapezius
Latissimus Dorsi
Latissimus Dorsi
Broad flat muscle with extensive origin from
• Lower 6 thoracic vertebrae• Lumbar + sacral vertebrae• Lumbar fascia • Posterior 1/3rd iliac crest• Last four ribs• Inferior angle scapula
Latissimus Dorsi
Broad flat muscle with extensive origin
Relatively small insertion onto floor of bicipital groove of proximal humerus
Latissimus Dorsi
Broad flat muscle with extensive origin
Relatively small insertion onto floor of bicipital groove of proximal humerus
Right Side, Anterior View
The most superficial muscles are
Trapezius
Latissimus Dorsi
Deltoid
Deltoid
Has three groups of fibres
Posterior
Middle
Anterior
Deltoid
Posterior fibres and middle fibres arise respectively from the spine and acromion of the scapula
Deltoid
Posterior fibres and middle fibres arise from the spine and acromion of the scapula
Both insert with the anterior fibres onto the deltoid tuberosity on the lateral aspect of the shaft of the humerus
Underneath Trapezius there are
3 muscles that
arise from the midline
insert sequentially onto the medial border of the scapula from top to bottom
Levator Scapulae
Arises from C1-4
Inserts onto superior aspect
Raises the scapula
Rhomboid Minor
Directly below Levator Scapulae
Retracts the scapula
Rhomboid Major
Directly below Rhomboid Minor
Retracts the scapula
Levator Scapulae
Rhomboid Minor
Rhomboid Major
Supraspinatus arises from the Supraspinous Fossa of the scapula
It attaches to the upper part of the Greater Tuberosity of the Humerus
It abducts the arm
Infraspinatus arises from the Infraspinous Fossa of the scapula
It attaches to the posterior part of the Greater Tuberosity of the Humerus
It externally rotates the arm
Teres Minor arises from the upper part of the Lateral Border of the Scapula
It attaches to the Inferior part of the Greater Tuberosity of the Proximal Humerus
It externally rotates the arm
Posterior View
Teres Major arises from the inferior angle of the scapula and adjacent lateral border
There are three spaces in the
posterior aspect of the Shoulder
Region
3 spaces Posterior Shoulder Region
Quadrangular Space
Triangular Space
Triangular Interval
Teres minor superiorly
The Quadrangular Space is an area bounded by
Teres Minor superiorly
Teres Major inferiorly
The Quadrangular Space is an area bounded by
Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps medially
The Quadrangular Space is an area bounded by
The Quadrangular Space is an area bounded by
Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps medially
Shaft of the Humerus Laterally
The Quadrangular Space is an area bounded by
Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps medially
Shaft of the Humerus Laterally
ContentsAxillary nerve
The Quadrangular Space is an area bounded by
Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps medially
Shaft of the Humerus Laterally
ContentsAxillary nerve Posterior circumflex humeral artery
The Quadrangular Space is an area bounded by
Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps medially
Shaft of the Humerus laterally
The Triangular Space is an area medial to the quadrangular space bounded by
Teres Minor superiorly
The Triangular Space is an area medial to the quadrangular space bounded by
Teres Minor superiorly
Teres Major inferiorly
The Triangular Space is an area medial to the quadrangular space bounded by
Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps laterally
The Triangular Space is an area medial to the quadrangular space bounded by
Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps laterally
The Triangular Space is an area medial to the quadrangular space bounded by
Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps laterally
The Triangular Space is an area medial to the quadrangular space bounded by
ContentsCircumflex Scapular Artery
The Triangular Interval is an area just below the quadrangular space bounded by
Teres Major superiorly
The Triangular Interval is an area just below the quadrangular space bounded by
Teres Major superiorly
Long head of Triceps medially
The Triangular Interval is an area just below the quadrangular space bounded by
Teres Major superiorly
Long head of Triceps medially
Shaft of the Humerus laterally
The Triangular Interval is an area just below the quadrangular space bounded by
ContentsRadial nerve
Teres Major superiorly
Long head of Triceps medially
Shaft of the Humerus laterally
The Triangular Interval is an area just below the quadrangular space bounded by
ContentsRadial nerve Profunda Brachii artery
Teres Major superiorly
Long head of Triceps medially
Shaft of the Humerus laterally
The Triangular Interval is an area just below the quadrangular space bounded by
Quadrangular SpaceAxillary NervePosterior circumflex humeral artery
Summary of Spaces and contents around the Posterior Shoulder Region
Quadrangular SpaceAxillary NervePosterior circumflex humeral artery
Triangular SpaceCircumflex scapular artery
Summary of Spaces and contents around the Posterior Shoulder Region
Quadrangular SpaceAxillary NervePosterior circumflex humeral artery
Triangular SpaceCircumflex scapular artery
Triangular IntervalRadial NerveProfunda Brachii
Summary of Spaces and contents around the Posterior Shoulder Region
Quadrangular SpaceAxillary NervePosterior circumflex humeral artery
Triangular SpaceCircumflex scapularartery
Triangular IntervalRadial NerveProfunda Brachii
Summary of Spaces and contents around the Posterior Shoulder Region
Summary of Muscles
Posterior Shoulder Region
Posterior Chest Wall
TrapeziusOrigin Medial third of superior nuchal
line; external occipital spinous processes of C7 - T12 vertebrae
Insertion Upper fibres to lateral third of clavicle, lower fibres to acromio and spine of scapula
Action Superior fibers elevate, middle fibers retract, and inferior fibers depress scapula
Nerve Supply Spinal root of accessory nerve (CN XI) (motor) and cervical nerves (C3 and C4) (pain and proprioception)
Blood Supply Transverse cervical artery
Posterior Chest Wall
Latissimus DorsiOrigin Spinous processes of lower 6
thoracic, all lumbar and sacral vertebrae, thoracolumbar fascia, iliac crest, inferior 3 or 4 ribs, inferior angle of scapula
Insertion Floor of intertubercular groove of humerus
Action Extends, adducts, and internally rotates humerus; pulls body up toward arms during climbing
Nerve Supply Thoracodorsal nerve (C6, C7, and C8)
Blood Supply Thoracodorsal artery
DeltoidOrigin Lateral third of clavicle,
acromion, and spine of scapulaInsertion Deltoid tuberosity on middle
of lateral shaft of humerusAction Anterior part: flexes and
internally rotates arm; Middle part: abducts arm; Posterior part: extends and externally rotates arm
Nerve Supply Axillary nerve (C5 and C6)Blood Supply Deltoid branch of
thoracoacromial artery
Posterior Chest Wall
Posterior Chest Wall
Levator ScapulaeOrigin Posterior tubercles of
transverse processes of C1 - C4 vertebrae
Insertion Superior part of medial border of scapula
Action Elevates scapula and tilts glenoid inferiorly by rotating scapula
Nerve Supply Dorsal scapular (C5) and anterior rami of cervical (C3 and C4) nerves
Blood Supply Dorsal scapular artery
Posterior Chest Wall
Rhomboid MinorOrigin Lower part of nuchal ligament
and spinous processes of C7 T1 vertebrae
Insertion Medial border of scapula at level of spine
Action Retracts and rotates scapula to move glenoid inferiorly; fixes scapula to thoracic wall
Nerve Supply Dorsal scapular nerve ( C4 and C5)
Blood Supply Dorsal scapular artery
Posterior Chest Wall
Rhomboid MajorOrigin Spinous processes of T2 - T5
vertebraeInsertion Lower part of medial border of
scapulaAction Retracts and rotates scapula to
move glenoid inferiorly; fixes scapula to thoracic wall
Nerve Supply Dorsal scapular nerve ( C4 and C5)
Blood Supply Dorsal scapular artery
Posterior Chest Wall
SupraspinatusOrigin Supraspinous fossa of scapula
Insertion Superior facet on greater tuberosity of humerus
Action Abduction of armNerve Supply Suprascapular nerve (C4, C5
and C6)Blood Supply Suprascapular artery
Posterior Chest Wall
InfraspinatusOrigin Infraspinous fossa of scapulaInsertion Middle facet on greater
tuberosity of humerusAction Externally rotates armNerve Supply Suprascapular nerve (C5 and
C6)Blood Supply Suprascapular and circumflex
scapular arteries
Posterior Chest Wall
Teres MinorOrigin Superior part of lateral border
of scapulaInsertion Inferior facet on greater
tuberosity of humerusAction External rotation of the armNerve Supply Axillary nerve (C5 and C6)Blood Supply Subscapular and circumflex
scapular arteries
Posterior Chest Wall
Teres MajorOrigin Lower third of lateral border of
scapula near the inferior angleInsertion Medial lip of bicipital groove of
humerusAction Adducts and internally rotates
armNerve Supply Lower subscapular nerve (C6
and C7)Blood Supply Subscapular and circumflex
scapular arteries
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