DSF Anatomy of Shoulder and Pectoral Region

Question 1

Tendons

Answer 1

Connect muscles to bones

Question 2

Ligaments

Answer 2

Connect bone to bone

Question 3

Strain

Answer 3

Muscle/Tendon injury

Question 4

Sprain

Answer 4

Ligament injury

Question 5

Arthritis

Answer 5

Cartilage damage

Question 6

3 bones of shoulder

Answer 6

Scapula - Glenoid Process (socket of shoulder)
Humerus - Humeral Head (ball of shoulder)
Clavicle (collarbone)

Question 7

Static stabilizers of the shoulder

Answer 7

Glenoid labrum (cartilage)
Shoulder capsule
Glenohumeral ligaments (superior, middle, inferior)

Acromioclavicular (AC) joint - AC ligaments
Coracoclavicular ligaments - Trapezoid and conoid
Coracoacromial ligament

Question 8

Glenoid Labrum

Answer 8

Cartilaginous structure: surround the edges of the glenoid
Doubles the depth of the glenoid
Provides 50% of static stability of shoulder
Enhances joint stability by increasing contact SA for humeral head
Resection results in 20% loss of resistance to translation from a compressive load

Question 9

Shoulder capsule

Answer 9

Twice the SA humeral head
Capsule reinforced by rotator cuff
Lined w/ synovium
Ligamentous thickenings

Question 10

Inferior Glenohumeral Ligament (IGHL)

Answer 10

Major stabilizer of GH joint

Anterior and posterior bands w/ interposed axillary pouch

Question 11

Muscles contributing dynamic stability of shoulder

Answer 11

Long head of biceps
Deltoid
Scapular stabilizers
Rotator Cuff Most important

Question 12

Long Head of the Biceps

Answer 12

Adds to anterior shoulder stability by resisting force in abduction and external rotation
Decreases stress placed on IGHL

Question 13

Anterior rotator cuff

Answer 13

Subscapularis
Origin: subscapular fossa
Insertion: Lesser tuberosity
Action: Internal rotation
Innervation: subscapular nerve

Question 14

Superior rotator cuff

Answer 14

Supraspinatus
Origin: supraspinous fossa
Insertion: Greater tuberosity
Action: Abduction
Innervation: suprascapular nerv

Question 15

Posterior rotator cuff

Answer 15

Infraspinatus
Origin: Infraspinous fossa
Insertion: Greater tuberosity
Action: external rotation
Innervation: suprascapular nerve

Teres Minor
Origin: Lateral border of scapula
Insertion: Greater tuberosity
Action: External rotation
Innervation: axillary nerve

Question 16

4 rotator cuff muscles

Answer 16

Subscapularis
Supraspinatus
Infraspinatus
Teres minor

Question 17

Deltoid

Answer 17

Origin: clavicle, acromion, scapular spine
Insertion: deltoid tuberosity, mid-humerus
Action: flexion, abduction, extension
Innervation: Axillary nerve

Question 18

Pectoralis Major

Answer 18

Origin: clavicle, sternum, ribs
Insertion: Humerus
Action: Adduction, internal rotation
Innervation: medial and lateral pectoral nerves

Question 19

Pectoralis Minor

Answer 19

Origin: 3rd-5th ribs
Insertion: coracoid process
Action: rotates scapula, assists in respiration
Innervation: medial and lateral pectoral nerves

Question 20

Triceps

Answer 20

Origin: Long head - inferior glenoid, Medial and lateral heads - humerus
Insertion: olecranon
Innervation: radial nerve
Extends elbow

Question 21

Rotator Cuff disorders

Answer 21

Greatest incidence: >40 age group
Subacromial bursa: sandwiched b/w acromion and proximal humerus
Decreased volume of SA space - increased wear and degeneration of soft tissue structures
Wide range of pathology