The Pectoral Girdle and Shoulder

Question 1

what is the collarbone comprised off?

Answer 1

the clavicle and scapula

Question 2

does the collarbone have an attachment to the axial skeleton?

Answer 2

yes via the clavicular attachments

Question 3

what is the glenohumeral joint?

Answer 3

articulation between the glenoid cavity and head of humerus also known as the shoulder joint

Question 4

what is the acromion?

Answer 4

the flattened hard part on the end of the clavicle

Question 5

is the surgical neck of the humerus inferior to the anatomical neck?

Answer 5

yes

Question 6

what ranges of movement are there at the shoulder joint?

Answer 6

protraction and retraction of scapula, rotation of humerus

Question 7

is the shoulder joint stable?

Answer 7

no, we sacrifice stability for a range of movement

Question 8

what is the function of the levator scapulae?

Answer 8

pull scapula up

Question 9

what muscles are around the shoulder joint?

Answer 9

teres major and minor, rotator cuff, deltoid and trapezius, supraspinatus, rhomboid major and minor, infraspinatus, levator scapulae

Question 10

what tendon is usually chronic or acute presentatio ns?

Answer 10

supraspinatus as pain, weakness and instability

Question 11

what happens in axillary nerve injury?

Answer 11

atrophy of deltoid, reduced sensation over C5 dermatome of skin

Question 12

what are the issues with surgical neck injuries?

Answer 12

axillary nerve injury and deltoid impairment

Question 13

what injury is easily missed?

Answer 13

posterior dislocation of shoulder joint

Question 14

what is winging of the scapula and what could cause it?

Answer 14

medial border and inferior angle of scapula pull away from posterior thoracic wall which injures the long thoracic nerve innervating serratus anterior. Can be caused by penetrating wounds, iatrogenic such as chest drains or neuritis.

Question 15

what type of joint is the shoulder joint?

Answer 15

ball and socket synovial joint between the head of humerus and the glenoid fossa of scapula

Question 16

what compromises the stability of the joint?

Answer 16

incongruent joint surfaces and a thin and lax joint capsule

Question 17

where is the joint weakest?

Answer 17

inferiorly

Question 18

how is stability improved?

Answer 18

glenoid labrum, ligaments, biceps tendon and rotator cuff muscles

Question 19

what is the coraaco-acromial arch and what is it’s function?

Answer 19

it is the acromion and coracoid process and the coracoacromial ligament which prevents superior displacement of the humerus

Question 20

which muscles form the rotator cuff and what are their functions?

Answer 20

teres minor, infra and supraspinatus, and they stabilise the shoulder joint by holding head of humerus into the glenoid fossa