1. LEC: Anatomy: Upper Extremity I (Revised)
Muscles OF
Shoulder & Pectoral Region

2. Objectives
Know the landmarks of the bony structures of the shoulder and axillary regions.
Discuss the muscles of pectoral and shoulder regions in terms of their origin, insertion, nerve supply and actions.
Understand how muscles are responsible for the movements (adduction, abduction, flexion and extension) at the shoulder joint.
Know the rotator cuff muscles, external and internal rotators.

3. Surface Anatomy

4. Surface Anatomy

5. Bony Skeleton Axial? Appendicular? Can you name some?
Shoulder Girdle..

6. Bony Skeleton

7. Shoulder Girdle

8. Pectoral Girdle Direct: Clavicle, Scapula from the trunk
Pectoralis minor, trapezius and rhomboids.
Indirect : Muscles of the great axillary folds as Pectoralis Major, and Latissimus dorsi.

9. Clavicle

10. Anterior Scapula. -angles, borders -glenoid cavity, -acromion,
-coracoid process,
-Subscapular fossa
Humerus.
-Head,
-Surgical neck
-Anatomical neck
-Greater tubercle
-Lesser tubercle
-Intertubercular
(bicipital) groove
acromion
anatomical neck
coracoid process
Lesser tubercule
Greater tubercule
surgical neck
bicipital groove
glenoid cavity

11. Posterior Clavicle. Acromioclavicular joint Scapula. - Spine
- Acromion
- Supraspinous fossa
- Infraspinous fossa
Humerus.
- Head
- Anatomical neck,
- Surgical neck,
- Deltoid tuberosity
- Spiral (radial) groove.
Acromioclavicular joint
Supraspinous Fossa
anatomical neck
surgical neck
Spine
Deltoid Tuberosity
Infraspinous Fossa
Radial Groove

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

13. Name the action

14. We need MUSCLES for all that!!
Muscles are named by either their;
Attachments “Sternohyoid”
Location ---- ”Pectoralis”
Action “Levator”
Shape ---- ”Quadratus”
Direction of fibers ---- “Rectus”
Nerve supply of the muscles tells us the story about it’s embryological origin.

16. Pectoralis Major: 2 parts
Pectoralis minor
- deep to pectoralis major
- protraction of scapula
- guide to axilla
Pectoralis Major: 2 parts
- Together (adduction, medial rotation)
Clavicular head (flexion)
Sternocostal head (extension)
(common insertion: lateral lip of intertubercular groove)
Clavicular
Sternocostal

18. Trapezius: 3 parts Superior fibers elevate Middle fibers retract
(insert lateral 1/3 of clavicle)
Middle fibers retract
(insert acromion)
Inferior fibers depress
(insert spine of scapula)
- Acting together, the
superior and inferior
fibers will rotate scapula.
Superior
Middle
Inferior

19. Latissimus Dorsi: Extends, adducts and medially rotates Humerus.
-(inserts floor of intertubercular groove)
Extends, adducts and
medially rotates
Humerus.
Swimming,
And
Climbing a tree

20. - retract / inferior rotate scapula
Posterior view:
- Trapezius
- Latissimus Dorsi
- Deltoid
Trapezius
Rhomboids
Deltoid
Rhomboids:
- minor and major
- retract / inferior rotate
scapula
Teres Major
Latissimus
Dorsi
Teres major:
- inserts near Latissimus dorsi
- adduct / medially rotate arm

21. Shoulder Flexion Anterior Arm. – Biceps brachi – Coracobrachialis
Actions:
Biceps – supination + flexion (shoulder, elbow)
Coracobrachialis – weak flexion / adduction (shoulder)

22. Anterior (flexion, med. rotation) Middle (abduction)
Deltoid: 3 parts
Anterior (flexion, med. rotation)
Middle (abduction)
Posterior (extension, lat. rotation)
(common insertion: deltoid tuberosity)
Posterior
Anterior
Deltoid

23. Shoulder Extension Posterior Arm. Triceps (3 heads) -long head extends
Action: Extension
Axillary Nerve
Teres
minor
Deltoid
Long
Lateral
Triceps
Medial

24. Key Muscles that act across the Shoulder Joint.
Adduction – pectoralis major, lattisimus dorsi.
Abduction – deltoid, supraspinatus.
Flexion – pectoralis major, deltoid (anterior),
– coracobrachialis, biceps.
Extension – latissimus dorsi, deltoid (posterior);
– pectoralis major from flexed position
- triceps (long head).
Medial Rotation
– subscapularis, pectoralis major, deltoid (anterior),
– latissimus dorsi, teres major;
Lateral Rotation – infraspinatus, teres minor,
deltoid (posterior).
This slide will be repeated through the first week lectures, will add up as we proceed with the axilla and scapular region

25. Thank you