5. 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
7. 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
8. Latissimus Dorsi
Broad flat muscle with
extensive origin
Relatively small insertion
onto floor of bicipital groove
of proximal humerus
9. Latissimus Dorsi
Broad flat muscle with
extensive origin
Relatively small insertion
onto floor of bicipital groove
of proximal humerus
Right Side, Anterior View
13. 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
14. Underneath Trapezius there are
3 muscles that
arise from the midline
insert sequentially onto the medial border of the
scapula from top to bottom
19. 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
20. 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
21. 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
27. Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps
medially
The Quadrangular Space is an area bounded by
28. The Quadrangular Space is an area bounded by
Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps
medially
Shaft of the Humerus
Laterally
29. The Quadrangular Space is an area bounded by
Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps
medially
Shaft of the Humerus
Laterally
30. Contents
Axillary 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
31. Contents
Axillary 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
34. Teres Minor superiorly
Teres Major inferiorly
The Triangular Space is an area medial to the
quadrangular space bounded by
35. Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps
laterally
The Triangular Space is an area medial to the
quadrangular space bounded by
36. Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps
laterally
The Triangular Space is an area medial to the
quadrangular space bounded by
37. Teres Minor superiorly
Teres Major inferiorly
Long head of Triceps
laterally
The Triangular Space is an area medial to the
quadrangular space bounded by
Contents
Circumflex Scapular Artery
40. Teres Major superiorly
Long head of Triceps
medially
The Triangular Interval is an area just below the
quadrangular space bounded by
41. 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
42. Contents
Radial 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
43. Contents
Radial 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
45. Quadrangular Space
Axillary Nerve
Posterior circumflex
humeral artery
Triangular Space
Circumflex scapular
artery
Summary of Spaces and contents around the
Posterior Shoulder Region
46. Quadrangular Space
Axillary Nerve
Posterior circumflex
humeral artery
Triangular Space
Circumflex scapular
artery
Triangular Interval
Radial Nerve
Profunda Brachii
Summary of Spaces and contents around the
Posterior Shoulder Region
47. Quadrangular Space
Axillary Nerve
Posterior circumflex
humeral artery
Triangular Space
Circumflex scapular
artery
Triangular Interval
Radial Nerve
Profunda Brachii
Summary of Spaces and contents around the
Posterior Shoulder Region
49. Posterior Chest Wall
Trapezius
Origin 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
50. Posterior Chest Wall
Latissimus Dorsi
Origin 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
51. Deltoid
Origin Lateral third of clavicle,
acromion, and spine of scapula
Insertion Deltoid tuberosity on middle
of lateral shaft of humerus
Action 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
52. Posterior Chest Wall
Levator Scapulae
Origin 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
53. Posterior Chest Wall
Rhomboid Minor
Origin 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
54. Posterior Chest Wall
Rhomboid Major
Origin Spinous processes of T2 - T5
vertebrae
Insertion Lower part of medial border of
scapula
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
55. Posterior Chest Wall
Supraspinatus
Origin Supraspinous fossa of scapula
Insertion Superior facet on greater
tuberosity of humerus
Action Abduction of arm
Nerve Supply Suprascapular nerve (C4, C5
and C6)
Blood Supply Suprascapular artery
56. Posterior Chest Wall
Infraspinatus
Origin Infraspinous fossa of scapula
Insertion Middle facet on greater
tuberosity of humerus
Action Externally rotates arm
Nerve Supply Suprascapular nerve (C5 and
C6)
Blood Supply Suprascapular and circumflex
scapular arteries
57. Posterior Chest Wall
Teres Minor
Origin Superior part of lateral border
of scapula
Insertion Inferior facet on greater
tuberosity of humerus
Action External rotation of the arm
Nerve Supply Axillary nerve (C5 and C6)
Blood Supply Subscapular and circumflex
scapular arteries
58. Posterior Chest Wall
Teres Major
Origin Lower third of lateral border of
scapula near the inferior angle
Insertion Medial lip of bicipital groove
of humerus
Action Adducts and internally rotates
arm
Nerve Supply Lower subscapular nerve (C6
and C7)
Blood Supply Subscapular and circumflex
scapular arteries