Upper limb - common condiitions and anatomy

Question 0

Where does supraspinatus originate and insert? What is its action?

Answer 0

Supraspinous fossa (posterior aspect of scap) to superior facet of great tuberosity

Abduction initiation (30 degrees)

Question 1

What are the 4 rotator cuff muscles? Acronym?

Answer 1

Supraspinatus
Infraspinatus
Subscapularis
Teres minor

Question 2

Where does infraspinatus originate and insert? What is its action?

Answer 2

Infraspinous fossa (posterior aspect of scap) to middle facet on greater tuberosity

External rotation

Question 3

Where does teres mminor originate and insert? Action? Which muscle shares this action?

Answer 3

Lat border of scapula/inspinatous fossa to inferior facet of greater tuberosity
External rotation
Infraspinatus (and some of their fibres co-exist)

Question 4

Where does subscapularis originate and insert? Action?

Answer 4

Subscapular fossa (anterior) to lesser tuberosity on humerus (nb this is more anterior than greater tuberosity).
Internal rotation

Question 5

What test is used to assess abduction? Which rotator cuff muscle is responsiible for this? Explain the test.

Answer 5

Empty can test
Supraspinatus
Patient stretch arms up and holds them 90 degrees from body (?). Patient then asked to pronate arms so that thumb points downwards (like emptying a can). Examiner presses down on arms, patients needs to abduct to resist the pressure. The action of deltoid s lost by this pronation so only the supraspinatus is being tested.

Question 7

Which test is used to test external rotation? which musclees are being assessed?

Answer 7

Patient flexes elbow to 90 degrees (but no flexion at shoulder), examineer puts one hand on elbow to stop abduction, asks patient to externally rotate forearms.
Infraspinatus and teres minor