SPLAT - Internal Rotation Muscles

Question 1

Subscapularis

Answer 1

PA:
+ subscapular fossa (most of anterior surface of scapula)

DA:
+ lesser tubercle of the humerus

N:
+ upper and lower subscapular nerves (C5, C6*, C7)

A:
+ medially rotates the shoulder joint
+ adducts the shoulder joint
+ helps hold humeral head in glenoid cavity

Question 2

Pectoralis major (clavicular head and sternocostal head)
Clavicular: 1 PA,
Sternocostal: 3 PA
1 DA, 2N (5R), 2 A together, 2 A alone

Answer 2

PA:
\+ clavicular head: anterior surface of medial half of clavicle
\+ sternocostal head: 
     anterior surface of sternum
     superior 6 costal cartilages
     aponeurosis of external oblique 

DA:
+ lateral lip of intertubercular sulcus of humerus

N:
+ lateral and medial pectoral nerves
+ clavicular head: C5, C6*
+ sternocostal head: C7, C8, T1

A:
together:
+ adducts and medially rotates shoulder
+ draws scapula anteriorly and inferiorly
alone:
+ clavicular head: flexes shoulder joint
+ sternocostal head: extends shoulder joint from flexed position

Question 3

Latissimus Dorsi

Answer 3

O:
\+ spinous processes of inferior six thoracic vertebrae
\+ thoracolumbar fascia
\+ Iliac crest
\+ Inferior three or four ribs

I:
+ floor of intertubercular sulcus (groove) of humerus

N:
+ thoracodorsal nerve (C6, C7, C8)

A:
+ extends, adducts, and medially rotates shoulder joint
+ raises body toward arms during climbing

Question 4

Anterior Deltoid

Answer 4

PA:
+ lateral third of the clavicle
+ acromion and spine of the scapula

DA:
+ deltoid tuberosity of the humerus

N:
+ axillary nerve (C5, C6)

A:
anterior (clavicular) part:
+ flexes the shoulder joint
+ medially rotates the shoulder joint

Question 5

Teres Major

Answer 5

PA:
+ Inferior part of lateral border of scapula
+ Posterior surface of inferior angle of scapula

DA:
+ Medial lip of intertubercular sulcus fo humerus

N:
+ Lower subscapular nerve (C5, C6*)

A:
+ Adducts shoulder joint
+ Medially rotates shoulder joint