Scapular & Rotator Cuff Muscles Flashcards
Supplies a cuff around the glenohumeral joint to stabilize the head of the humerus in the glenoid fossa and control the movements at this joint.
Rotator Cuff
What are the 4 muscles of the rotator cuff?
1) Supraspinatus
2) Infraspinatus
3) Teres Minor
4) Subscapularis
Which 2 scapular muscles are not part of the rotator cuff?
1) Deltoid
2) Teres Major
Otherwise known as your shoulder cap and resembles an upside down triangle.
Deltoid
What are the 3 heads of the deltoid muscle?
1) Anterior Head
2) Middle Head
3) Posterior Head
Medial Attachment: anterolateral 1/3 of clavicle (anterior head), lateral acromion (middle head) and spine of scapula (posterior head)
Lateral Attachment: deltoid tuberosity
Deltoid
What is the action of all the heads of the deltoid muscle?
G-H Abduction
What are the 3 actions of the anterior head of the deltoid?
1) G-H Medial Rotation
2) G-H Flexion
3) G-H Horizontal Adduction
What are the 3 actions of the posterior head of the deltoid?
1) G-H Lateral Rotation
2) G-H Extension
3) G-H Horizontal Abduction
What does SItS stand for?
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis
The head of the humerus can be separated from the glenoid fossa by ___ cm when the muscles are cut.
2.5 cm
A muscle that fills the space above the spine of the scapula and travels deep to the acromion. It is vulnerable for impingement, which can cause tendonitis.
Supraspinatus
Medial Attachment: supraspinous fossa
Lateral Attachment: superior facet of greater tubercle of humerus and G-H joint capsule
Supraspinatus
What are the 2 actions of supraspinatus?
1) G-H Abduction (up to 90 degrees)
2) Scaption
Which muscle stabilizes the G-H joint by tucking the head of the humerus into the glenoid fossa, so it doesn’t run into the acromion?
Supraspinatus
Medial Attachment: infraspinous fossa
Lateral Attachment: middle facet of greater tubercle of humerus and G-H joint capsule
Infraspinatus
What is the action of infraspinatus?
G-H External Rotation
A small and cylindrical muscle with the same action as infraspinatus.
Teres Minor
Medial Attachment: lateral middle border of scapula (between triceps and teres major)
Lateral Attachment: inferior facet of greater tubercle of humerus and G-H joint capsule
Teres Minor
What is the action of teres minor?
G-H External Rotation
Medial Attachment: subscapular fossa
Lateral Attachment: lesser tubercle of humerus and G-H joint capsule
Subscapularis
What is the action of subscapularis?
G-H Internal Rotation
Medial Attachment: posterior surface of inferior angle of scapula
Lateral Attachment: medial lip of bicipital groove
Teres Major
What are the 3 actions of teres major?
1) G-H Internal Rotation
2) G-H Extension
3) G-H Adduction
Which muscle has the same actions as latissimus dorsi?
Teres Major
