1. SHOULDER ANATOMY

2. BONY ANATOMY

3. Humerus • proximal end articulates with scapula to from shoulder
• distal end articulates with bones of the forearm to form elbow

4. Scapula • the shoulder blade
Glenoid fossa has ring of cartilage called labrum to deepen the articular surface
• the glenoid fossa of the scapula articulates with the humerus to form the glenohumeral joint (shoulder)
• the acromion process articulates with the clavicle to from the acromioclavicular joint (tip of the shoulder)

5. Clavicle
• distally articulates with the acromion process to form the AC joint
• Proximally articulates with the sternum to form SC joint

6. Review of Joints
Glenoid fossa+humerus=glenohumeral joint (GH) (scapula)
Acromion process + clavicle =acromioclavicular (scapula) (AC)
Sternum + clavicle=sternoclavicular (SC)
Scapula+rib cage= scapulothoracic articulation

7. MUSCLATURE

8. Trapezius • large, triangular muscle
• starts at base of skull, runs out to tip of shoulder and down to the 12th thoracic vertebrae
• functions to shrug and square the shoulders

9. Rhomboids
• group of two muscles that run diagonally from the spine to the medial border of the scapula
• they function to retract the scapula

10. Latissimus Dorsi • the “lats” • gives wing like appearance to sides
• starts along the thoracic vertebrae of back and inserts on the anterior aspect of humerus
• functions extend , adduct and medially rotate the arm

11. Pectoralis Major • the chest muscle
• originates along the sternum and clavicle, inserts on the humerus
• it functions to:
~ adduct
~ flex
~medially rotate
the arm.

12. Deltoid • the muslce that gives contour to the shoulder
• originates along the spine of the scapula and clavicle, inserts on the humerus
• all fibers abduct the arm
• anterior fibers: flex and medially rotate arm
• posterior fibers: extend and laterally rotate arm

13. Biceps • the “popeye” muscle • on anterior aspect of arm
• crosses both the shoulder and elbow
• flexes the arm

14. Triceps • on the posterior aspect of the arm
• crosses both the shoulder and elbow
• extends the arm

15. Rotator Cuff
Group of four muscles that act to hold the head of the humerus into the glenoid fossa
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis

16. Rotator Cuff cont. Supraspinatus: 1st 10 degrees of abduction
Infraspinatus: external rotation
Teres minor: external rotation
Subscapularis: internal rotation

17. Note that there are no muscles on the inferior aspect of the shoulder
** Note that there are no muscles on the inferior aspect of the shoulder!! This will be important when we talk about shoulder injuries

18. Labrum Ring of cartilage similar to the menisci of the knee.
Deepens the articular surface of the genoid fossa and adds to the stability of the shoulder