Shoulder Muscles

Question 1

What are the 5 anterior shoulder muscles?

Answer 1

deltoidpec majorpec minorserratus anteriorsubclavius

Question 2

Innervation of deltoid

Answer 2

axillary nerveC5-C6

Question 3

Innervation of pec major

Answer 3

sternal head = medial pectoral nerve, C8-T1clavicular head = lateral pectoral nerve, C5-C7

Question 4

Innervation of subclavius

Answer 4

nerve to subclaviusC5-C6

Question 5

Innervation of pec minor

Answer 5

medical pectoral nerveC5-C7

Question 6

Innervation of serratus anterior

Answer 6

long thoracic nerve C5-C7

Question 7

Action of deltoid

Answer 7

ant fibres = flexion and medial rotationmiddle fibres = abductionposterior fibres = extension and lateral rotation

Question 8

Action of pec major

Answer 8

sternal head = extension of flexed armclavicular head = extension of arm at shoulderadduction, medial rotation

Question 9

Action of serratus anterior

Answer 9

rotates scapula up so arm can be raised above 90 degreesholds scapula against the thoracic wall

Question 10

Action of pec minor

Answer 10

draws scapula anteriorly and inferiorly against thoracic walldepresses the shoulder

Question 11

Action of subclavius

Answer 11

depresses and anchors clavicle

Question 12

What happens when there is damage to the axillary nerve?

Answer 12

atrophy of deltoid fibreslack of sensation in regimental badge areacannot abduct past 15 degrees

Question 13

What is Poland Syndrome?

Answer 13

pec major and pec minor are absenthave breast hypoplasiaabsence of rib segments 2-4

Question 14

What happens when there is an injury to the long thoracic nerve?

Answer 14

winging of scapula due to paralysis of serratus anterior- scapula protrudes when you ask the patient to push with the limbscapula is not held against the thoracic wall

Question 15

How can the long thoracic nerve be damaged?

Answer 15

• trauma to the shoulder- repetitive movements involving the shoulder - by structures becoming inflamed and pressing on the nerve

Question 16

What muscles are in the anterior compartment of the arm?

Answer 16

biceps brachiibrachialiscoracobrachialis

Question 17

Innervation of anterior compartment of the arm?

Answer 17

musculocutaneous nerveC5-C6

Question 18

Action of biceps brachii

Answer 18

main supinator of the arm weak flexor at shoulder and elbow

Question 19

Action of brachialis

Answer 19

main flexor at elbow

Question 20

Action of coracobrachialis

Answer 20

flexes arm at shoulderadducts arm at shoulder

Question 21

Attachments of bicep brachii

Answer 21

short head = coracoid process of scapula to radial tuberositylong head = supraglenoid tubercle to radial tuberosity

Question 22

What does a tap on bicep brachii muscle test?

Answer 22

C6 spinal segment

Question 23

Describe biceps tendonitis

Answer 23

occurs due to repetitive microtrauma on the muscledue to throwing and racquet sportscauses inflammation of the tendon

Question 24

Describe rupture of the biceps tendon

Answer 24

occurs at the tendon of the long head of bicepswould not notice much weakness, due to brachialis and supintator muscles

Question 25

What sign would you see with a rupture of the biceps tendon?

Answer 25

popeye’s sign muscle will bulge because it is not fixed when the arm is flexed

Question 26

What muscles do you find in the posterior compartment of the arm?

Answer 26

triceps brachiianconeus

Question 27

What are the three heads of the triceps brachii and where do they attach?

Answer 27

long head = infraglenoid tuberclelateral head = portion of humerus superior to the radial groovemedial head = portion of humerus inferior to the radial grooveALL attach to the olecranon of the ulna

Question 28

Action of the triceps brachii

Answer 28

main extensor of the arm at elbow

Question 29

Innervation of teh tricep brachoo

Answer 29

radial nerveC5-C8

Question 30

What does a tap on the triceps brachii muscle test?

Answer 30

C7 spinla segment

Question 31

Innervation of the anconeus

Answer 31

radial nerveC5-C8

Question 32

Action of the anconeus

Answer 32

assists triceps in arm extension at elbow