The shoulder joint is formed by the articulation of the glenoid cavity of the scapula and the head of the humerus. It is a ball and socket synovial joint that allows for polyaxial movement. The joint is strengthened by ligaments like the glenohumeral and coracohumeral ligaments, as well as the rotator cuff muscles. Injuries and conditions that can affect the shoulder joint include dislocations, bursitis, rotator cuff tears, and frozen shoulder.

1. Shoulder Joint
Lecture by
Dr.N.Mugunthan.MBBS,MS,DNB,MNAMS,PhD
Associate Professor,
MGMC&RI.
1© Dr.N.Mugunthan

2. Learning objectives
Shoulder joint:
• Type & variety
• Articular surfaces
• Ligaments
• Relations
• Blood & nerve supply
• Movements
• Applied anatomy
LAQ: Describe the shoulder joint under following headings: a. articular
surfaces b. ligaments c. movements d. applied anatomy (2+3+3+2)2© Dr.N.Mugunthan

3. How to describe a joint
9. Movements
10. Muscles producing
movements
11. Unique features of
particular joint
12. Applied anatomy
1. Definition
2. Type of joint
3. Variety of joint
4. Articular surfaces
5. Ligaments
6. Relations
7. Blood supply
8. Nerve supply 3© Dr.N.Mugunthan

4. Shoulder joint
Definition :
 Shoulder joint is formed
by articulation of the
scapula (glenoid cavity)
and head of the
humerus
 Glenohumeral joint
4© Dr.N.Mugunthan

5. Type of joint
Synovial joint
Polyaxial
5© Dr.N.Mugunthan

6. Variety of joint
Ball and socket
variety
6© Dr.N.Mugunthan

7. Articular surfaces
Proximal articular surface :
Glenoid fossa of scapula
 Pyriform in shape
 Surface area, concavity
of glenoid fossa
increased by glenoidal
labrum
 Glenoidal labrum – fibro
cartilaginous ribbon like
structure
 Covered with hyaline
cartilage
7© Dr.N.Mugunthan

8. Articular surfaces cont…
Distal articular surface:
The head of humerus
Hemispherical in
shape
Covered with hyaline
cartilage
8© Dr.N.Mugunthan

9. Shoulder joint – weak joint
o Glenoid fossa is too small
& shallow
o to hold the head of the
humerus in place
o The head is four times
the size of glenoid cavity
o Structurally, it is a weak
joint
Stability of the joint is ?
9© Dr.N.Mugunthan

10. Ligaments
True ligament:
1. Capsule
Accessory ligaments:
2. Glenohumeral ligaments
3. Transverse humeral
ligament
4. Coracohumeral ligament
5. Secondary socket /
ligament
(Coracoacromial arch)
6. Glenoidal labrum
10© Dr.N.Mugunthan

11. Capsule
Loose fibrous covering
Inner surface lined with
synovial membrane
Attachments:
Proximal attachments:
Margins of glenoid fossa
(proximal to glenoid
labrum)
Distal attachments:
Anatomical neck of
humerus (except inferiorly,
extends to shaft for
1.25cm) 11© Dr.N.Mugunthan

12. Glenohumeral ligaments :
Three :
1. Superior band
2. Middle band
3. Inferior band
Seen on inner side of
ant. part of capsule
Accessory ligaments
13© Dr.N.Mugunthan

13. Attachments :
Proximally: (Glenoid)
 All 3 bands attached to
upper end of glenoid
fossa
Distal : (Humerus)
 Upper band – top of
lesser tuberosity
 Middle band – lower
part
 Lower band – shaft just
below lesser tuberosity
Glenohumeral ligaments cont…
14© Dr.N.Mugunthan

14. Transverse humeral ligament
Stretches between tops
of greater & lesser
tuberosities
Long head of biceps
tendon passes out deep
to this ligament
15© Dr.N.Mugunthan

15. Coracohumeral ligament
Attachment :
Lateral margin of root of
coracoid process to
Greater tuberosity of
humerus
All the accessory ligaments
attach either lesser/greater
tuberosity of humerus
16© Dr.N.Mugunthan

16. Coracoacromial ligament
(secondary socket)
Triangular band
Base –attached to lateral
margin of coracoid
process
Apex – attached to tip of
acromion
Coracoid process,ligament
& acromion together form
– coracoacromial arch
Which forms secondary
socket for the joint
17© Dr.N.Mugunthan

17. Rotator cuff
(Codman’s musculo-tendinous cuff)
Laxity & weakness of
joint is compensated
by this cuff
Derived from tendons
of – SITS
1. Supraspinatus
2. Infraspinatus
3. Teres minor
4. Subscapularis 18© Dr.N.Mugunthan

18. Expansions from these
tendons fuse with
capsule
Strengthens the
capsule all round
(except inferiorly)
Injury to rotator cuff –
recurrent dislocation
Rotator cuff cont…
(Codman’s musculo-tendinous cuff)
19© Dr.N.Mugunthan

19. Glenoidal labrum
Fibro cartilaginous ribbon
like structure
Attached to margins of
the glenoid cavity
Increase the depth of
glenoid cavity
Increase the articular
surface of glenoid
Lined with hyaline
cartilage
21© Dr.N.Mugunthan

20. Relations of shoulder joint
a) Muscles
b) Bursae
c) Vessels & nerves
24© Dr.N.Mugunthan

21. a) Muscles:
Anteriorly:
• Subscapularis,
coracobrachialis, short
head of biceps and
deltoid.
Posteriorly:
• Infraspinatus, teres
minor and deltoid.
Relations of shoulder joint
25© Dr.N.Mugunthan

22. a) Muscles: cont…
Superiorly:
• Long tendon of biceps
inside the capsule
• Supraspinatus outside
the capsule
Inferiorly:
• Long head of the triceps
 Deltoid – covers
superiorly, anteriorly,
posteriorly & laterally
Relations of shoulder joint
cont…
26© Dr.N.Mugunthan

23. Subacromial (Subdeltoid)
bursa:
 Lies between deltoid
muscle & capsule
 Does not communicate
with joint
 Extends between
supraspinatus and
acromion & coracoacromial
arch
Longest bursa in the body
b) Bursae related to shoulder joint cont…
30© Dr.N.Mugunthan

24. Blood supply
Arterial supply:
 Anterior circumflex
humeral artery
 Posterior circumflex
humeral artery
 Suprascapular artery
 Circumflex scapular
branch of Subscapular
artery.
Venous drainage :
 Corresponding veins
33© Dr.N.Mugunthan

25. Nerve supply
A twig from lateral
pectoral nerve
Suprascapular nerve
Axillary nerve
(posterior division)
34© Dr.N.Mugunthan

26. Movements @ shoulder joint
Flexion & extension
Adduction & abduction
Medial & lateral rotation
Circumduction
35© Dr.N.Mugunthan

27. Flexion & extension
Transverse axis :
Flexion:
• Pectoralis major
(clavicular part),
• Deltoid (anterior fibres)
coracobrachialis
• Assisted by biceps.
Extension:
• Deltoid (posterior fibres)
• Teres major,
• Latissimus dorsi and
pectoralis major
(sternocostal part)
36© Dr.N.Mugunthan

28. Abduction & adduction
Antero-posterior axis
Abduction:
• Supraspinatus : 0-30°
• Deltoid (middle fibers) 0-90°
• Serratus anterior &
trapezius: 90-180°
Adduction:
• Pectoralis major
• Latissimus dorsi
• Teres major
• Corachobrachialis
• Biceps (short head)
37© Dr.N.Mugunthan

29. Medial & lateral rotation
Longitudinal axis
Medial rotation:
• Pectoralis major
• Deltoid (anterior fibres)
• Latissimus dorsi
• Teres major and
subscapularis.
Lateral rotation:
• Infraspinatus
• Deltoid (posterior fibres)
and teres minor. 38© Dr.N.Mugunthan

30. Circumduction
• Combination of 3 axis
• Combination of all the
muscles around
shoulder
39© Dr.N.Mugunthan

31. Applied anatomy
• Referred pain from
diaphragm, pleura &
peritoneum (supplied by
phrenic nerve -C3,C4 &) to tip
of shoulder via supraclavicular
nerve (C3&C4)
• Dislocation
• Bursitis
• Supraspinatus Tendinitis
• Rupture of supraspinatus
• Rotator cuff injury
• Frozen shoulder
• Arthroscopy & arthroplasty
40© Dr.N.Mugunthan

32. Applied anatomy
• Referred pain from
diaphragm, pleura &
peritoneum (supplied by
phrenic nerve -C3,C4 &) to tip
of shoulder via supraclavicular
nerve (C3&C4)
• Dislocation
• Bursitis
• Supraspinatus Tendinitis
• Rupture of supraspinatus
• Rotator cuff injury
• Frozen shoulder
• Arthroscopy & arthroplasty
41© Dr.N.Mugunthan

33. Applied anatomy
• Referred pain from
diaphragm, pleura &
peritoneum (supplied by
phrenic nerve -C3,C4 &) to tip
of shoulder via supraclavicular
nerve (C3&C4)
• Dislocation
• Bursitis
• Supraspinatus Tendinitis
• Rupture of supraspinatus
• Rotator cuff injury
• Frozen shoulder
• Arthroscopy & arthroplasty
42© Dr.N.Mugunthan

34. Applied anatomy
• Referred pain from
diaphragm, pleura &
peritoneum (supplied by
phrenic nerve -C3,C4 &) to tip
of shoulder via supraclavicular
nerve (C3&C4)
• Dislocation
• Bursitis
• Supraspinatus tendinitis &
• Rupture of supraspinatus
• Rotator cuff injury
• Frozen shoulder
• Arthroscopy & arthroplasty
43© Dr.N.Mugunthan

35. Applied anatomy
• Referred pain from
diaphragm, pleura &
peritoneum (supplied by
phrenic nerve -C3,C4 &) to tip
of shoulder via supraclavicular
nerve (C3&C4)
• Dislocation
• Bursitis
• Supraspinatus Tendinitis
• Rupture of supraspinatus
• Rotator cuff injury
• Frozen shoulder
• Arthroscopy & arthroplasty
44© Dr.N.Mugunthan

36. Applied anatomy
• Referred pain from
diaphragm, pleura &
peritoneum (supplied by
phrenic nerve -C3,C4 &) to tip
of shoulder via supraclavicular
nerve (C3&C4)
• Dislocation
• Bursitis
• Tendinitis
• Rupture of supraspinatus
• Rotator cuff injury
• Frozen shoulder
• Arthroscopy & arthroplasty
45© Dr.N.Mugunthan

37. Applied anatomy
• Referred pain from
diaphragm, pleura &
peritoneum (supplied by
phrenic nerve -C3,C4 &) to tip
of shoulder via supraclavicular
nerve (C3&C4)
• Dislocation
• Bursitis
• Supraspinatus Tendinitis
• Rupture of supraspinatus
• Rotator cuff injury
• Frozen shoulder
• Arthroscopy & arthroplasty
46© Dr.N.Mugunthan

38. Take home message
Shoulder joint:
• Type & variety
• Articular surfaces
• Ligaments
• Relations
• Blood & nerve supply
• Movements
• Applied anatomy
49© Dr.N.Mugunthan

39. 50© Dr.N.Mugunthan