Rotator Cuff Muscles Flashcards
Shape and DoF: Subscapularis
large multipennate muscle
fibres run superolaterally to form a broad thick tendon
Attachments: Subscapularis
O: medial 2/3rd subscapular fossa
I: lesser tubercle of humerus & the capsule
Action and Function: Subscapularis
Strong medial rotator
Assists Adduction
Holds humeral head in glenoid fossa
Undoing bra/scratching back
Nerve supply: Subscapularis
upper and lower subscapular nerves
C5,6,7
Shape and DoF: Supraspinatus
thin and slender
passes laterally over the top of the shoulder joint
Attachments: Supraspinatus
O: medial 2/3rds supraspinous fossa
I: deep surface blends with JC, then inserts to UPPER facet of GREATER tubercle
Nerve supply: Supraspinatus
Suprascapular nerve (C5, 6)
Function and Action: Supraspinatus
Initiation of abduction
Braces humeral head in glenoid fossa
Used in side reaching
Shape and DoF: Teres Minor
thin muscle
runs superolaterally forming a narrow tendon
Attachments of Teres Minor
O: upper 2/3rd of lateral border of scapula
I: inferior facet on greater tubercle of humerus
Nerve supply: Teres Minor
Axillary Nerve
C5, 6
Action and function of teres minor
Reinforces lower JC
Lateral rotation - in anatomical position
In abduction - Lateral rotation and adduction
Used in brushing hair
Shape and DoF of infraspinatus
thick, triangular muscle
runs superolaterally converging into narrow tendon
Attachments of infraspinatus
O: medial 2/3rds infraspinous fossa
I: middle fact on greater tubercle of humerus and posterior JC
Nerve supply of infraspinatus
suprascapular nerve
C5, 6
