1. Muscles of the Pectoral & Shoulder region
Dr. Sama-ul-Haque Dr. Rania Jabr

2. Objectives
Identify the bony components of the shoulder. girdle including the Clavicle, Scapula and Humerus.
Describe how primary muscles are responsible for the following shoulder motion: adduction, abduction, flexion, extension.

3. Bony Skeleton

4. Bones of the Upper Limb
1-Bones of the Pectoral Girdle: Clavicle and Scapula
2- Arm : Humerus.
3-Forearm : Radius & Ulna.
4-Wrist : Carpal bones
5-Hand: Metacarpals & Phalanges

5. Clavicle
It is considered as a long bone but it has no medullary (bone marrow) cavity.

6. Clavicle

7. Scapula (anterior)

8. Scapula (posterior)

10. Articulations of clavicle
Clavicle articulates Medially with the manubrium of the Sternum at the Sternoclavicular joint .
Laterally with the Scapula at the Acromioclavicular joint
Inferiorly with the 1st rib at the Costoclavicular Joint

11. Pectoral (Shoulder) Girdle
connects the upper limb to the axial skeleton
formed of two bones:
Clavicle and Scapula.
formed of two joints
Sternoclacvicular joint
Acromioclavicular joint A S

12. Humerus

14. Anterior acromion anatomical neck coracoid process Lesser tubercule
glenoid cavity
surgical neck
anatomical neck
Greater tubercule
Lesser tubercule
bicipital groove

15. Posterior Acromioclavicular joint Supraspinous Fossa anatomical neck
Spine
Supraspinous Fossa
Infraspinous Fossa
Radial Groove
Deltoid Tuberosity
surgical neck
anatomical neck
Acromioclavicular joint

16. Movements of the shoulder joint :
Abduction / adduction
Flexion / extension
Rotation – internal (medial)
- external (lateral)
Movements of the shoulder girdle :
(increase range of movement of upper limb)
Protraction / Retraction
Elevation / Depression
Rotation: Superior / Inferior
Circumduction

17. Muscles of the (Pectoral) Region
Pectoralis major.
Pectoralis minor.
Subclavius.
Serratus anterior.

18. Pectoralis Major Clavicular head: Lateral lip of bicipital groove.
Medial ½ of front of the clavicle.
Sternocostal head:
Sternum.
Upper 6 costal cartilages.
Lateral lip of bicipital groove.

19. Nerve supply: medial & lateral pectoral nerve Action :
Adduction and medial rotation of the arm.
Clavicular head helps in flexion of arm (shoulder).

20. Pectoralis Minor Coracoid process. 3 45
Nerve supply: medial pectoral nerve
Action:
Depression & protraction of the shoulder.
Elevate the ribs during deep inspiration.

21. Subclavius Subclavian groove in the inferior surface of clavicle.
1st rib
Nerve supply:
Nerve to subclavius
Action:
Fixes the clavicle during movement of shoulder joint.

22. Serratus anterior Upper 8 ribs Nerve supply: Action:
Front of the medial border of scapula.
Upper 8 ribs
Nerve supply:
Long thoracic nerve.
Action:
Depression & protraction of the scapula (boxing)
Raising the arm above 90 degree (climbing).
Accessory muscle of respiration

23. Injury of long thoracic nerve
Subscapularis
en.wikipedia.org/wiki/Serratus_anterior_muscle
Injury of long thoracic nerve: Winged Scapula:
Cause; Paralysis of serratus anterior as it is
"big swing muscle" or "boxer's muscle”
Antagonist of Rhomboids

24. Deltoid Action: Nerve supply:
Lateral third of clavicle, acromion, spine of scapula
Deltoid tuberosity of humerus
Nerve supply:
Axillary nerve
Action:
Anterior fibers : Flexion, medial rotation
Middle fibers: abduct arm from 15°- 90°.
Posterior fibers : Extension, lateral rotation

25. D

26. DELTOID MUSCLE

27. Axillary nerve injury Deformity: flat shoulder
Cause: fracture surgical neck of humerus.
Clinical signs:
Paralysis of deltoid and teres minor.
Loss of abduction from

29. TRAPEZIUS External occipital protuberance. Ligamentum nuchae.
Spine of C7
Spine of T1-T12
Clavicle, acromion and spine of scapula

30. Nerve supply: Spinal part of accessory (11th cranial) nerve.
Action:
Abduction > 90 (climbing)
Upper fibers: elevate scapula.
Middle fibers: retract scapula
Lower fibers: depress scapula.

31. Both deltoid and Trapezius muscles give the shoulder its characteristic shape.

32. Poland Syndrome Congenital Absence of Pectoralis Major,
Partial or complete absence