The Shoulder

Question 1

What two anatomical structures is the shoulder complex viewed as?

Answer 1

The shoulder girdle & the shoulder proper

Question 2

What makes up the shoulder girdle?

Answer 2

Scapulae and Clavicles

Question 3

What makes up the shoulder proper?

Answer 3

Scapula and Humerus

Question 4

Name the four different joints in the shoulder complex

Answer 4

1. Sternoclavicular Joint
2. Acromioclavicular Joint
3. Scapulothoracic Joint
4. Glenohumeral Joint

Question 5

Sternoclavicular Joint

Answer 5

girdle - gliding joint

***only place the shoulder attaches to axial skeleton

Question 6

Acromioclavicular Joint

Answer 6

girdle - gliding joint

Question 7

Scapulothoracic Joint

Answer 7

girdle - not really a true joint - gliding

“Scapulothoracic Mechanism”

Question 8

Glenohumeral Joint

Answer 8

shoulder proper - ball and socket

Question 9

Bony anatomical landmarks

Scapula - what type of bone is it?

Answer 9

It’s a flat bone
superior angle, inferior angle, superior border, vertebral/medial border, axillary/lateral border, spine, supraspinous fossa, infraspinous fossa, subscapular fossa, acromion process, coracoid process, glenoid fossa/cavity

Question 10

Clavicle

Answer 10

Long bone
S shaped
Provides a mechanical barrier against scapular protraction (ABDuction)

Question 11

Sternum

Answer 11

Flat bone
superior portion - manubrium
central porion - body or gladiolus
inferior portion - xiphoid process

Question 12

Humerus

Answer 12

**Only bone in the arm

head, anatomical neck, greater tubercle, lesser tubercle, intertubercular groove/bicipital groove

Question 13

Movements of the scapulae (shoulder girdle)

Answer 13

elevation, depression
upward/downward rotation
protraction (ABDuction)/retraction (ADDuction)
tilt
lateral wining **Not a normal movement/position…indicates weak rhomboids/middle trapezius

Question 14

Movement about the glenohumeral joint

Answer 14

flexion/extention
ABDuction/ADDuction
horizontal flexion (horizontal ABDuction)/extension/hyperextension (horizontal ABDuction)
INTernal rotation/EXTernal rotation
circumduction

Question 15

Trapezius

Answer 15

O: base of the skull & occipital protuberance, neck ligaments (ligamentum nuchae), spinous processes of C7 and all Ts
I: part1-post border lateral third of clavicle
part2-sup aspect acromion process
part3-sup aspect scapular spine
part4-inf/med aspect scapular spine
A: part1-elevation, upward rotation,lateral flexion at neck, ext/hyperext at neck
part2-upward rotation, retraction
part3-retraction
part4-retraction, upward rotation, depression
WR: Shoulder shrugs, seated rows with protraction & retraction, vertical rowing, dips

Question 16

Levator Scapulae

Answer 16

O: Transverse processes of C1-C4
I: Sup angle/med border above spine
A: Lateral flex at neck & ext/hyperext at neck & elevation
WR: shoulder shrugs

Question 17

Rhomboids

Answer 17

O: Spinous processes C7 through T5
I: med border of scapula below spine
A: downward rotation & retraction & slight elevation
WR: seated rowing with protraction & retraction

Question 18

Serratus Anterior (boxer’s muscle)

Answer 18

O: anterolateral surface of upper 9 ribs
I: med border scapula
A: protracts scapula & upward rotation; if scapula is fixed by pec major, may aid in breathing
WR: dumbbell bench presses(must protract scapulae), shoulder presses

Question 19

Pectoralis Minor

Answer 19

O: ant aspect ribs #3,4,5
I: coracoid process
A: depress scapula & protraction & ant tilt & downward rotation; when scapulae are fixed, may aid in breathing
WR: important stabilizing M. when performing bench press or seated rows

Question 20

shoulder proper

Answer 20

glenohumeral joint

Question 21

Why is the shoulder so mobile? Why the great ROM?

Answer 21

1. Ball and socket joint with shallow socket…“golf ball on a quarter”
2. scapulohumeral rhythem (scapulohumeral cooperation)
3. muscles and connective tissue are taut, but not tight

Question 22

Deltoid

Answer 22

O: anterorlateral third of clavicle; acromion process; inf aspect scapular spine
I: deltoid tuberosity
A: ABD; horizonta ABD/ADD; INT/EXT rotation; flex/ext
WR: ant-front shoulder raises, bench presses; middle-lateral shoulder raises; post-seated rows, prone lateral raises, lat pull downs/pull ups/chin ups

Question 23

Coracobrachialis

Answer 23

O: coracoid process
I: Middle med aspect humerus
A: flex, ADD, Horizontal ADD
WR: cable cross-overs

Question 24

Rotator cuff (S.I.T.S.)

Answer 24

Supraspinatus
Infraspinatus
Teres Minor
Supscapularis

Question 25

Supraspinatus

Answer 25

***most often injured R.C. muscle
O: med 2/3s supraspinous fossa
I: sup aspect greater trochanter
A: acts to stabilize glenohumeral joint; some EXT rotation; ABD (especially first 30Deg)

Question 26

Infraspinatus

Answer 26

***second most often injured R.C. Muscle
O: med side infraspinous fossa
I: post aspect greater tubercle
A: EXT rotation; horizontal ABD; EXT

Question 27

Teres Minor

Answer 27

O: Middle of lateral border of scapula (axillary)
I: post aspect greater trochanter
A: same action as infraspinatus

Question 28

Subscapularis

Answer 28

O: subscaupular fossa
I: lesser tubercle
(goes through armpit)
A: INT rotation; ADD; EXT ( Actions similar to Latissimus Dorsi & Teres Major)

Question 29

What is the only rotator cuff muscle that does not insert on the greater tubercle and performs internal rotation?

Answer 29

Subscapularis, only one

Question 30

Teres Major

Answer 30

Latissimus Dorsi’s little helper
O: inf third lateral boarder of scapula
I: intertubercular groove of humerus
A: EXT; ADD; INT rotation

Question 31

Latissimus Dorsi

Answer 31

O: post aspect iliac crest; sacrum; spinous processes T6-L5; slips of the 3 most inferior costae
I: intertubercular groove/bicipital groove
A: EXT, ADD, INT rotation; horizontal ABDuction

Question 32

Pectoralis Major

Answer 32

O: Upper fibers(clavicular portion) - medial half anterior portion of clavicle. Middle & lower fibers (sternal portion) - costal cartilage of the 1st 6 costae & manubrium & body of the sternum
I: intertubercular groove humerus
A: horizontal ADD (most important job); flex/EXT; INT rotation; ADD

Question 33

What 3 muscles insert on the intertubercular groove-from medial to lateral?

Answer 33

Teres Major
Lats
Pec Major
***all three of these are internal rotators alone with the subscapularis