Rotator Cuff

Question 1

Give the Origin, Insertion, Innervation, Action, and Test of:

Supraspinatus

Answer 1

Origin:
Supraspinous fossa of the scapula

Insertion:
Superior facet of greater tubercle of the humerus

Innervation:
Suprascapular Nerve (C5,6)

Action:
First 15 degrees of abduction of arm
Helps stabilise glenohumeral joints

Test:
Resisted abduction of arm from fully adducted position. Palpate muscle at the same time.

Question 2

Give the Origin, Insertion, Innervation, Action, and Test of:

Infraspinatus

Answer 2

Origin:
Infraspinous fossa of the scapula

Insertion:
Middle facet of the greater tubercle of the humerus.

Innervation:
Suprascapular Nerve (C5,6)

Action:
Laterally rotates the arm
Helps stabilise glenohumeral joint

Test:
Resisted lateral rotation of arm. Palpate muscle at the same time.

Question 3

Give the Origin, Insertion, Innervation, Action, and Test of:

Teres Minor

Answer 3

Origin:
Middle part of the lateral border of the scapula

Insertion:
Inferior facet of the greater tubercle of the humerus.

Innervation:
Axillary Nerve (C5,6)

Action:
Laterally rotates the arm
Helps stabilise glenohumeral joint

Test:
None listed.

Question 4

Give the Origin, Insertion, Innervation, Action, and Test of:

Subscapularis

Answer 4

Origin:
Subscapular fossa of the scapula

Insertion:
Lesser tubercle of the humerus

Innervation:
Upper and Lower Subscapular Nerves (C5 and C6 respectively).

Action:
Medially rotates the arm
Helps stabilise the glenohumeral joint

Question 5

Name the rotator cuff muscles

Answer 5

Supraspinatus
Infraspinatus
Teres Minor
Subscapularis

Remember: “SITS” muscles