Muscles of the Shoulder Girdle

Question 1

Trapezius

Answer 1

O : External occipital protuberance, medial 1/3 of superior nuchal line, ligamentum nuchae and spinous processes of C7-T12
I : Lateral 1/3 of clavicle, acromion process and spine of scapula
SMA :
1. Elevate the scapula at the ScC jt
2. Retracts the scapula at the ScC jt
3. Upwardly rotates the scapula at the ScC jt
4. Depresses the scapula at the ScC jt
RMA :
1. Extends the head and neck at the spinal joints
2. Contralaterally rotates the head and neck at the spinal joints
3. Laterally flexes the head and neck at the spinal joints

Question 2

Levator Scapulae

Answer 2

O : TVP of C1-C4
I : Medial border of the scapula, from the superior angle to the root of the spine of scapula
SMA :
1. Elevates the scapula at the ScC jt RMA :
1. Extends the head and neck at the spinal joints
2. Laterally flexes the head and neck at the spinal joints

Question 3

Rhomboids Minor

Answer 3

O : SP of C7-T1 and inferior nuchal ligament
I : The root of the spine of the scapula
A :
1. Retract the scapula at the ScC jt
2. Elevate the scapula at the ScC jt
3. Downwardly rotate the scapula at the ScC jt.

Question 4

Rhomboids Major

Answer 4

O : SP of T2-T5
I : Medial border of the scapula between the root of the spine of scapula and the inferior angle
A :
1. Retract the scapula at the ScC jt
2. Elevate the scapula at the ScC jt
3. Downwardly rotate the scapula at the ScC jt

Question 5

Deltoid

Answer 5

O : Lateral 1/3 of the clavicle, acromion process and spine of scapula
I : Deltoid tuberosity of humerus
SMA :
1. Flexes the arm at the GH jt
2. Extends the arm at the GH jt
3. Medially rotates the arm at the GH jt
4. Laterally rotates the arm at the GH jt
5. Horizontally flexes the arm at the GH jt
6. Horizontally extends the arm at the GH jt
7. Abducts the arm at the GH jt

Question 6

Latissimus Dorsi

Answer 6

O : Inferior angle of the scapula, SP of T7-L5, lower 3-4 ribs, thoracolumbar aponeurosis to the posterior iliac crest
I : Medial lip of the intertubecular groove of the humerus
A :
1. Medially rotates the arm at the gh joint
2. Adducts the arm at the gh joint
3. Extends the arm at the gh joint

Question 7

Teres Major

Answer 7

O : Inferior angle and inferior 1/3 of dorsal surface of inferior lateral border of the scapula
I : Medial lip of the intertubercular groove of the humerus
A :
1. Medially rotates the arm at the Gh joint
2. Adducts the arm at the Gh joint
3. Extends the arm at the Gh joint