prac 2- GHJ

Question 1

GHJ lacks

Answer 1

bony stability

Question 2

passive capsuloligamentous structures

Answer 2

permit a large range of movement whilst tightening in the outer range of movement to resist excessive range.

Question 3

Which passive & active structures provide support to the GHJ in the anatomical position?

Answer 3

A = deltoid and SST
P = coracohumeral lig, superior glenohumeral lig

Question 4

Which active structures control movement of the humeral head on the glenoid through the normal ranges of active movements?

Answer 4

rotator cuffs

Question 5

What would be the disadvantage of excessive superior translation of the head of humerus during upper limb abduction?

Answer 5

could impinge on structures in subacromial space (sub-acromial bursa, supraspinatus tendon, LHB)

Question 6

What is the primary muscle producing abduction at the glenohumeral joint? Explain why.

Answer 6

Deltoid because large PSA

- supraspinatus for early abd.

Question 7

force couple between the deltoid and the rotator cuff during GHJ abduction.

Answer 7

up. pull of deltoid is balanced by dwn. pull of rotator cuff muscles.
superior and inferior mvmt cancel
resultant/net force to stabilise humeral head

Question 8

Flexion of GHJ

Answer 8

Anterior deltoid
Middle deltoid
Clavicular head pectoralis major Coracobrachialis
Biceps brachii

Question 9

Extension of GHJ

Answer 9

Sternal head pectoralis major Latissimus dorsi
Teres major
Posterior deltoid

Question 10

Abduction

Answer 10

Middle deltoid
Anterior deltoid
Supraspinatus (SST)

Question 11

Adduction

Answer 11

Coracobrachialis
lat dorsi
pec major - both heads

Question 12

Internal rot.

Answer 12

Teres major
Subscap.
coracobrachialis
lat dorsi
pec major

Question 13

external rot.

Answer 13

teres minor

infraspinatus

Question 14

horizontal flx / abd

Answer 14

pec major

anterior deltoid

Question 15

horizontal ext / abduct.

Answer 15

posterior deltoid

infraspinatus