The shoulder joint is a complex of four joints that provide a wide range of motion. It includes the sternoclavicular, acromioclavicular, scapulothoracic, and glenohumeral joints. The glenohumeral joint is a ball and socket joint formed by the humeral head and glenoid cavity that allows the greatest range of movement. Stability is provided by the rotator cuff muscles, long head of the biceps brachii, bony processes, and extracapsular ligaments. The document describes the anatomy and functions of the bones, joints, muscles, nerves and blood supply of the shoulder complex.

1. ANATOMY
& APPLIED ASPECTS OF SHOULDER JOINT
PMR PG Teaching- August 2016
Dr. Jimy Jose
Resident, Deptt. Of PMR
SMS Medical College, Jaipur

2. OSTEOLOGY
The bone framework of the shoulder consists of:
the clavicle and scapula, which form the pectoral girdle
(shoulder girdle)
 the proximal end of the humerus.

3. Clavicle
• The clavicle is the only bony attachment between the trunk and the upper limb.
• It is palpable along its entire length and has a gentle S-shaped contour
• forward-facing convex part medial and
• forward-facing concave part lateral.
The acromial (lateral) end of the clavicle is flat
The sternal (medial) end is more robust and somewhat quadrangular in shape.
the surfaces and margins of the clavicle are roughened by the attachment of muscles that
connect the clavicle to the thorax, neck, and upper limb.
 The superior surface is smoother than the inferior surface.

5. Scapula
The scapula is a large, flat triangular bone with:
• three angles (lateral, superior, and inferior);
• three borders (superior, lateral, and medial);
• two surfaces (costal and posterior); and
• three processes (acromion, spine, and coracoid process)

6. Posterior view of right
scapula.

7. Anterior view
of scapula

8. • A large triangular-shaped roughening (the infraglenoid tubercle) inferior to
the glenoid cavity is the site of attachment for the long head of the triceps
brachii muscle.
• The lateral angle of the scapula is marked by a shallow, somewhat comma-
shaped glenoid cavity,
• which articulates with the head of the humerus to form the glenohumeral joint

9. Lateral view
of scapula

10. • supraglenoid tubercle is located superior to the glenoid cavity and is the site
of attachment for the long head of the biceps brachii muscle.
• A prominent spine subdivides the posterior surface of the scapula into a
small, superior supraspinous fossa and a much larger, inferior infraspinous
fossa.
• The acromion, which is an anterolateral projection of the spine, arches over
the glenohumeral joint and articulates, via a small oval facet on its distal end,
with the clavicle.

11. • Unlike the posterior surface, the costal surface of the scapula is unremarkable,
being characterized by a shallow concave subscapular fossa over much of its
extent .
• The costal surface and margins provide for muscle attachment, and the costal
surface, together with its related muscle (subscapularis), moves freely over the
underlying thoracic wall.
• The lateral border of the scapula is strong and thick for muscle attachment,
• medial border and much of the superior border is thin and sharp.

12.  The superior border is marked on its lateral end by:
• the coracoid process, a hook-like structure that projects anterolaterally and is
positioned directly inferior to the lateral part of the clavicle
• the small but distinct suprascapular notch, which lies immediately medial to
the root of the coracoid process.

13. JOINTS
Four joints Within the
Shoulder Complex:
1. Sternoclavicular joint
2. Acromioclavicular joint
3. Scapulothoracic joint
4. Glenohumeral joint
1.Sterno
Clavicular
2.Acromio
clavicular
3.Gleno
humeral
4.Scapulothoracic joint

14. The
sternoclavicular
joint
is surrounded by
a joint capsule
and is reinforced
by four
ligaments:
anterior and posterior
sternoclavicular
ligaments are anterior
and posterior, respectively,
to the joint
the costoclavicular ligament links the
proximal end of the clavicle to the first rib
and related costal cartilage.
interclavicular ligament
links the ends of the two
clavicles to each other ; and to
the superior surface of the
manubrium of sternum
STERNOCLAVICULAR JOINT

15. ACROMIOCLAVICULAR JOINT
It allows movement in the anteroposterior and vertical planes together with some axial rotation.
surrounded by a joint capsule and is reinforced by
LIGAMENTS:
acromioclavicular
ligament passing
between adjacent
regions of the
clavicle and
acromion
coracoclavicular ligament-
• between the coracoid process
of the scapula and the inferior
surface of the acromial end of
the clavicle
• anterior trapezoid ligament
(which attaches to the
trapezoid line on the clavicle)
& a posterior conoid
ligament (which attaches to
the related conoid tubercle)

16. GLENOHUMERAL
JOINT
 synovial ball and socket articulation between the head of the humerus and the glenoid cavity.
 Multiaxial wide range of movements provided at the cost of skeletal stability
 Joint stability - rotator cuff muscles, the long head of the biceps brachii , bony processes, extracapsular ligaments
The glenoid cavity is deepened
and expanded peripherally by the
glenoid labrum
Superiorly, this labrum is
continuous with the tendon of
the long head of the biceps
brachii muscle, which attaches
to the supraglenoid tubercle and
passes through the articular
cavity

17. The synovial membrane
• attaches to the margins of the articular surfaces
• loose inferiorly. (redundant region accommodates abduction
of the arm)
• also folds around the tendon of the long head of the biceps
brachii and extends along the tendon as it passes into the
intertubercular sulcus.
• protrudes through apertures in the fibrous membrane to form
bursae, which lie between the tendons of surrounding
muscles and the fibrous membrane.
The most consistent of these is the subtendinous bursa of
subscapularis, between the subscapularis muscle and the
fibrous membrane.

18. Other bursae are associated with the joint:
• between the acromion (or deltoid muscle)
and supraspinatus muscle (or joint
capsule) (the
subacromial or subdeltoid bursa)
• between the acromion and skin
• between the coracoid process and the
joint capsule
• in relationship to tendons of muscles
around the joint (coracobrachialis, teres
major, long head
of triceps brachii, and latissimus dorsi
muscles).
All these synovial structures reduce friction
between the tendons and adjacent
joint capsule and bone.

19. The fibrous membrane of the joint capsule attaches
to:
 the margin of the glenoid cavity
 outside the attachment of the glenoid labrum
 The long head of the biceps brachii muscle
 the anatomical neck of the humerus – the medial attachment occurs
more inferiorly than the neck and extends onto the
shaft. In this region, the fibrous membrane is also loose or folded in the
anatomical position. This redundant area of the fibrous membrane
accommodates abduction of the arm.
The fibrous membrane of the joint capsule is thickened by:
• Glenohumeral Ligaments
superior, middle, and inferior glenohumeral ligaments, which pass between the
superomedial margin of the glenoid cavity to the lesser tubercle
• The Coracohumeral Ligament
superiorly between the base of the coracoid process and the greater tubercle of
the humerus
• The Transverse Humeral Ligament
between the greater and lesser tubercles of the humerus -this holds the
tendon of the long head of the biceps brachii muscle in the intertubercular sulcus

20. Scapulothoracic Joint
 not a true joint - rather a point of contact
between the anterior surface of the scapula and
the posterior-lateral wall of the thorax
the scapula is typically positioned between the
second and the seventh rib, with the medial border
located about six (6) cm lateral to the spine

21. SURFACE ANATOMY

22. SURFACE ANATOMY

23. SURFACE ANATOMY

24. SURFACE ANATOMY

25.  Some muscles of the
shoulder connect the
scapula and clavicle to the
trunk.
• The trapezius
• Levator scapulae
• Rhomboids
 muscles connect the
clavicle, scapula, and body
wall to the proximal end of
the humerus.
• pectoralis major
• pectoralis minor
• latissimus dorsi
• teres major
• deltoid

26. TRAPEZIUS AND DELTOID
• The two most superficial muscles of the shoulder
• Together, they provide the characteristic contour of the shoulder
• the trapezius attaches the scapula and clavicle to the trunk.
• the deltoid attaches the scapula and clavicle to the humerus.
• Both the trapezius and deltoid are attached to opposing surfaces and margins of the
spine of the scapula, acromion, and clavicle.
• The scapula, acromion, and clavicle can be palpated between the attachments of
trapezius and deltoid.

27. Muscle Origin Insertion Innervation Function

29. • Together, the left and right trapezius muscles form a diamond or trapezoid shape, from
which the name is derived.
• The accessory nerve can be evaluated by testing the function of the trapezius muscle. This
is done by asking patients to shrug their shoulders against resistance.

31. Muscle Origin Insertion Innervation Function

32. Muscle Origin Insertion Innervation Function

35. Muscle Origin Insertion Innervation Function

37. Muscle Origin Insertion Innervation Function

39. Muscle Origin Insertion Innervation Function

43. four rotator cuff muscles-
supraspinatus
Infraspinatus
Teres minor
Subscapularis

44. • Tendons of the rotator cuff muscles (the
supraspinatus, infraspinatus, teres minor, and
subscapularis muscles) blend with the joint capsule
and form a musculotendinous collar that
surrounds the :
posterior, superior, and anterior aspects of the
glenohumeral joint
• This cuff of muscles stabilizes and holds the head
of the humerus in the glenoid cavity of the scapula
without compromising the arm's flexibility and
range of motion.
• The tendon of the long head of the biceps brachii
muscle passes superiorly through the joint and
restricts upward movement of the humeral head on
the glenoid cavity.

46. Blood supply:
ant & post circumflex humeral vessel.
Suprascapular vessel.
Subscapular vessel

47. Vascular supply of Glenohumeral joint
branches of the anterior and posterior circumflex humeral and suprascapular
arteries.
innervated by branches from the posterior cord of the brachial plexus, and
from the suprascapular, axillary nerves.

48. Nerve supply:
axillary nerve
musculo cutaneous nerve
suprascapular nerve

49. Internal rotation
Subscapularis
latissimus dorsi
anterior fiber of the deltoid
pectoralis major
teres major.
External rotators -
Infraspinatus
teres minor
posterior fibers of the deltoid.
Abductors
Deltoid
Supraspinatus
trapezius,
serratus anterior.
Adduction
Subscapularis
Infraspinatus
teres minor
Pectoralis
Latissimus dorsi
teres major
Flexion of the arm
Pectoralis major
biceps brachii
and anterior deltoid
Extension
posterior deltoid
teres major
Latissimus dorsi
The muscles noted previously can be divided into functional groups

50. References
Clinical Anatomy Snell’s
Gray’s Anatomy

51. Thank you