lecture 5- muscle acting on the shoulder

Question 1

pectoral gridle
role?

Answer 1

3 interconnecting bones: clavicle, humerus, scapula and rib cage
connects the upper limbs to the rib cage and allows for full range of motion

Question 2

joints and articulations of the pectoral griddle

Answer 2

sternocostal
sternoclavicular
acromioclavicualr
glenhumeral
costovertebral
scapula thoracic
interclavicular

Question 3

what type of joint in the glenohumeral joint

Answer 3

synovial ball and socket glenoid fossa is only 1/4 size humeral head, at any given time 25%-30% of the humeral head is in contact with the glenoid fossa

Question 4

glenoid labrum

Answer 4

fibrocartilage deepens glenoid fossa by 5-9mm

Question 5

glenoid humeral joint movements

Answer 5

Greatest ROM of all body joints
movements in all directions:
flexion/extension
adduction/abduction
internal/ external rotation
circumduction

Question 6

glenohumeral joint ligaments

Answer 6

Coracohumeral ligament= resists inferior and posterior translation
superior/ middle/ inferior glenoid ligament= resists anterior displacement or humeral head, tightens with external rotation

Question 7

shoulder joint/ flexion and extension

Answer 7

flexion:
deltoid
pectoralis major
biceps brachii
coracobrachialis
extension:
deltoid
latissimus dorsi
teres major
pec major
triceps brachii

Question 8

deltoid
origin insertion action

Answer 8

o: anterior border and upper surface of the lateral 1/3 of the clavicle, acromion and spine of the scapula
I: deltoid tuberosity of the humerus
A: abduction, flexion and extension of the shoulder

Question 9

pectorals major
origin insertion action

Answer 9

O=clavicular head: anterior surface of medial half of the clavicle
sternocostal head: anterior surface of the sternum, superior six costal cartridges, aponeurosis of the external oblique muscle
I: lateral lip of th eintertubercualr groove of the humerus
A: adducts and medially rotates the humerus, draws the scapula anteriorly and inferiorly, acting alone of the clavicular head flexes the humerus, and the sternocostal head will extend the humerus from a flexed position

Question 10

coracobrachialis
origin insertion action

Answer 10

O: tip of the coracoid process of the scapula
I: middle 1/3 of the medial surface of the humerus
A: flexes and adducts the shoulder joint

Question 11

latissimus Dorsi
origin insertion action

Answer 11

O: spinous process of the inferior 6 thoracic vertebrae, throaco-lumbar fascia iliac crest, and inferior 3-4 ribs
I: floor if the interbercular groove
A: extends, adducts medially rotates humerus; raises body towards arms when climbing

Question 12

theres major
origin insertion action

Answer 12

O: posterior aspect of the inferior angle of the scapula
I: medial lip of the bicipital grove
A: adduction at the shoulder joint, medial rotation of the shoulder joint extend the shoulder from a flexed position

Question 13

muscle insertions on the bicipital groove “a lady between two majors”

Answer 13

lateral lip of pec major
floor of bicipital groove: lats
medial lip: teres major

Question 14

abduction and adduction of the shoulder

Answer 14

abduction:
deltoid
supraspinatus covered with the rotator cuff
adduction:
coracobrachialis
pecs major
latissimus dorsi
teres major

Question 15

rotation

Answer 15

medial:
pec major
latissimus dorsi
teres major
subscapularis
lateral:
infraspinatus
teres minor

Question 16

special motion

Answer 16

horizontal adduction:
pec major
pec minor
latissimus dorsi
horizontal abduction:
teres minor
post. deltoid

Question 17

special area- Axilla

Answer 17

medial wall: serratus anterior/ thoracic wall
lateral wall: bicipital groove
anterior wall: pec. major and pec. minor
posterior: subscapularis, latissimus dorsi and teres major

Question 18

axilla contents

Answer 18

axillary vein, axillary artery, brachial plexus, lymph nodes