Shoulder & Pectoral
Region
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.
Surface Anatomy
Surface Anatomy
Bony Skeleton
• Axial?
• Appendicular?
• Can you name some?
• Shoulder Girdle..
Bony Skeleton
Shoulder Girdle
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.
Clavicle
Anterior
Scapula.
-angles, borders
-glenoid cavity,
-acromion,
-coracoid process,
-Subscapular fossa
Humerus.
-Head,
-Surgical neck
-Anatomical neck
-Greater tubercle
-Lesser tubercle
-Intertubercular
(bicipital) groove
Posterior
Clavicle.
Acromioclavicular joint
Scapula.
- Spine
- Acromion
- Supraspinous fossa
- Infraspinous fossa
Humerus.
- Head
- Anatomical neck,
- Surgical neck,
- Deltoid tuberosity
- Spiral (radial) groove.
Movements of the shoulder joint (Scapulohumeral):
Abduction / adduction
Flexion / extension
Rotation
Circumduction
– internal (medial)
- external (lateral)
Movements of the scapula (Thoracoappendicular):
(increase range of movement of upper limb)
Protraction / Retraction
Elevation / Depression
Rotation:
Superior / Inferior
Name the action
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.
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
Trapezius:
Superior
Middle
3 parts
-Superior fibers elevate
(insert lateral 1/3 of clavicle)
-Middle fibers retract
(insert acromion)
-Inferior fibers depress
(insert spine of scapula)
Inferior
- Acting together, the
superior and inferior
fibers will rotate scapula.
Latissimus Dorsi:
-(inserts floor of intertubercular groove)
-Extends, adducts and
medially rotates
Humerus.
Swimming,
And
Climbing a tree
Posterior view:
- Trapezius
- Latissimus Dorsi
- Deltoid
Rhomboids:
- minor and major
- retract / inferior rotate
scapula
Teres major:
- inserts near Latissimus dorsi
- adduct / medially rotate arm
Shoulder Flexion
Anterior Arm.
– Biceps brachi
– Coracobrachialis
Actions:
Biceps – supination + flexion (shoulder, elbow)
Coracobrachialis – weak flexion / adduction (shoulder)
Deltoid: 3 parts
-Anterior (flexion, med. rotation)
-Middle (abduction)
-Posterior (extension, lat. rotation)
-(common insertion: deltoid tuberosity)
Anterior
Posterior
Shoulder Extension
Posterior Arm.
-Triceps
(3 heads)
-long head extends
shoulder.
Action: Extension
Key Muscles that act across the Shoulder Joint.
Adduction
Abduction
Flexion
Extension
– pectoralis major, lattisimus dorsi.
– deltoid, supraspinatus.
– pectoralis major, deltoid (anterior),
– coracobrachialis, biceps.
– 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).
Thank you