1. SHOULDER
Kaan Yücel M.D., Ph.D
12.March.2014 Wednesday

2. shoulder Region of upper limb attachment to the trunk
Proximal segment of limb
overlaps parts of the trunk (thorax and back) and lower lateral neck.
includes
Pectoral
Scapular
Deltoid regions of the upper limb
lateral part (greater supraclavicular fossa) of lateral cervical region.
Overlies half of the pectoral girdle.

3. The pectoral (shoulder) girdle formed by:
Scapulae and clavicles
completed anteriorly by the manubrium of the sternum (part of the axial skeleton).

4. Bone framework of the shoulder
Clavicle & scapula [pectoral girdle-shoulder girdle]
Proximal end of humerus

5. The superficial muscles of the shoulder trapezius & deltoid muscles
together form the smooth
muscular contour over the
lateral part of the shoulder.
Connect scapula to trunk &
clavicle to arm. .

6. Joints The 3 joints in the shoulder complex : Sternoclavicular joint
Acromioclavicular joint
Glenohumeral joint

8. Muscles

9. The two most superficial muscles of the shoulder
trapezius and deltoid muscles.
Trapezius attaches scapula & clavicle to the trunk
Deltoid attaches scapula & clavicle to the humerus

10. POSTERIOR AXIOAPPENDICULAR MUSCLES EXTRINSIC SHOULDER MUSCLES
SUPERFICIAL
POSTERIOR AXIOAPPENDICULAR MUSCLES
EXTRINSIC SHOULDER MUSCLES
Trapezius & latissimus dorsi
DEEP
POSTERIOR AXIOAPPENDICULAR MUSCLES
EXTRINSIC SHOULDER MUSCLES
Levator scapulae & rhomboids

11. (INSTRINSIC SHOULDER) MUSCLES
SCAPULOHUMERAL
(INSTRINSIC SHOULDER) MUSCLES
6 scapulohumeral muscles
Deltoid, teres major, supraspinatus, infraspinatus, subscapularis, and teres minor
pass from scapula to humerus
Act on the glenohumeral joint.
All the intrinsic muscles but the deltoid and the subscapularis are muscles of the posterior scapular region.

12. Deltoid Large and triangular in shape
Base attached to the scapula and clavicle
Apex attached to the humerus

13. Deltoid Lateral 1/3 of clavicle Acromion Spine of scapula
Deltoid tuberosity of humerus

14. Deltoid Major function: Abduction of the arm
beyond the initial 15° accomplished by supraspinatus
Clavicular: flexes and medially rotates arm
Acromial: abduction of arm
Spinal: extends and laterally rotates arm

15. branch of the posterior cord of the brachial plexus
Deltoid
Innervation: Axillary nerve
branch of the posterior cord of the brachial plexus

17. Subscapularis Thick, triangular muscle
Lies on the costal surface of the scapula
Subscapular fossa
Lesser tubercle of humerus

18. Subscapularis Primary medial rotator of the arm Adducts the arm.
Joins the other rotator cuff muscles in holding the head of the humerus in the glenoid cavity during all movements of the glenohumeral joint!
Innervation: Superior and inferior subscapular nerves

20. POSTERIOR SCAPULAR REGION
4 muscles
pass between the scapula and proximal end of humerus:
POSTERIOR SCAPULAR REGION
Supraspinatus
Infraspinatus
Teres minor
Teres major

21. + part of long head of the triceps brachii,
passes between the scapula and the proximal end of the forearm.

22. Supraspinatus & Infraspinatus
Originate from 2 large fossae, 1 above and 1 below the spine, on the posterior surface of the scapula.
Insert on greater tubercle of the humerus.
Supraspinatus initiates abduction of the arm.
Infraspinatus laterally rotates the humerus.

23. Supraspinatus & Infraspinatus

24. Teres minor A cord-like muscle
Laterally rotates the humerus
Component of the rotator cuff.
Middle part of lateral border of scapula
Inferior facet of greater tubercle of humerus

25. Teres major Posterior surface of inferior angle of scapula
Medial lip of intertubercular sulcus of humerus
Medially rotates and extends the humerus.

26. ROTATOR CUFF MUSCLES (SITS muscles) 4 intrinsic shoulder muscles
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
(SITS muscles)
Form a musculotendinous rotator cuff around the glenohumeral joint.

27. ROTATOR CUFF MUSCLES Insertion exception: Supraspinatus Infraspinatus
Teres minor
greater tubercle
Subscapularis
lesser tubercle

28. ROTATOR CUFF MUSCLES Functional exception:
All except supraspinatus are rotators of the humerus
Supraspinatus, besides being part of the rotator cuff, initiates and assists the deltoid in the first 15° of abduction of the arm.

29. Gateways to the posterior scapular region Suprascapular foramen
The route through which structures pass between the base of the neck and the posterior scapular region.
Formed by
suprascapular notch of scapula
&
superior transverse scapular (suprascapular) ligament,
which converts the notch into a foramen.

30. Gateways to the posterior scapular region
The suprascapular nerve passes through the suprascapular foramen;
Suprascapular artery & suprascapular vein follow the same course as the nerve, but normally pass immediately superior to the superior transverse scapular ligament and not through the foramen.

31. Gateways to the posterior scapular region
Quadrangular space
axillary nerve & posterior circumflex humeral artery and vein

32. Gateways to the posterior scapular region
Triangular space
circumflex scapular artery and vein

33. Gateways to the posterior scapular region
Triangular interval
radial nerve ,profunda brachii artery (deep artery of arm)

34. Nerves
The two major nerves of the posterior scapular region: Suprascapular & Axillary nerves
originate from the brachial plexus in the axilla.

35. Suprascapular nerve Originates where?
Base of the neck from superior trunk of brachial plexus
Reach where through which space?
Posterior scapular region through suprascapular foramen
Which muscles innervates ?
Supraspinatus muscle & infraspinatus

36. Axillary nerve Originates where? Posterior cord of brachial plexus
Reach where through which space?
From the posterior wall of axilla to posterior scapular region through quadrangular space
Which muscles innervates ?
Deltoid & teres minor

37. Axillary nerve Cutaneous branch?
Superior lateral cutaneous nerve of the arm
carries general sensation from the skin over the inferior part of the deltoid muscle.

38. 3 major arteries in the posterior scapular region
Suprascapular artery
Posterior circumflex humeral artery
Circumflex scapular artery
These arteries contribute to an interconnected vascular network around the scapula.

39. Formation of anastomosis around the surgical neck of humerus
Posterior circumflex humeral artery anastomoses with anterior circumflex humeral artery and also with branches from:
profunda brachii
(brachial artery)
suprascapular
(subclavian artery)
thoracoacromial
(axillary artery)
arteries .

40. Movements of the shoulder girdle
Abduction of the shoulder is initiated by the supraspinatus; the deltoid can then abduct to 90 degrees.
Further movement to 180 degrees (elevation) is brought about by rotation of the scapula upwards by the trapezius and serratus anterior.
As soon as abduction commences at the shoulder joint, so the rotation of the scapula begins.

41. Principal muscles acting on the shoulder joint
Abductors
Supraspinatus
Deltoid
Adductors
Pectoralis major
Lattisimus dorsi
Extensors
Teres major
Deltoid (posterior fibres)
Flexors
Coracobrachialis
Deltoid (anterior fibres)
Medial rotators
Pectoralis major
Lattisimus dorsi
Teres major
Deltoid (anterior fibres)
Subscapularis
Lateral rotators
Infraspinatus
Teres minor
Deltoid (posterior fibres)