Superficial Back Muscles

Question 1

Trapezius

Answer 1

O: Superior nuchal line External occipital proturbance Nuchal ligament Spine of C7 to T12

I: Spine of scapula Acromion Lateral third of clavicle

A: On the scapula – elevation, retraction, depression, lateral rotation. Also – extend the head and neck, laterally flex the head and neck

N: Accessory Nerve (CN XI)

Question 2

Latissimus Dorsi

Answer 2

O: Spines of T6-L5 Median crest of sacrum Iliac crest

I: Intertubercular groove of humerus

A: Extend, adduct and medially rotate the humerus (handcuff muscle)

N: Thoracodorsal nerve

Question 3

Levator Scapulae

Answer 3

O: Transverse Processes of C 1-4

I: Medial border of scapula, above the spine

A: Elevate, retract and medially rotate scapula. Elevates scapula, downwardly rotate the scapula, laterally flex the head and neck, rotate the head and neck to the same side.

N:Dorsal scapular nerve

Question 4

Rhomboid Minor

Answer 4

O: Spinous Process of C-7 and T1

I: Medial border of scapula, at level of spine

A: Elevate, retract and medially rotate scapula.

Adduct the scapula (scapulothoracic joint)
Elevate the scapula (S/T joint)
Downwardly rotate the scapula (S/T joint)

I: Dorsal scapular nerve

Question 5

Rhomboid Major

Answer 5

O: Spinous Process of T-2 to T-5

I: Medial border of scapula, below level of spine

A: Elevate, retract and medially rotate scapula.

Adduct the scapula (scapulothoracic joint)
Elevate the scapula (S/T joint)
Downwardly rotate the scapula

N: Dorsal scapular nerve

Question 6

Deltoid

Answer 6

O: Posterior – spine of scapula

Intermediate – acromion
Anterior – lateral 1/3 of clavicle

I: Deltoid tuberosity of humerus

A: Flex and extend the shoulder

Abduct
Medially and laterally rotate

N: Axillary Nerve

Question 7

Supraspinatus

Answer 7

O: Supraspinous fossa

I: Greater tubercle of humerus

A: Abduct humerus (with deltoid)

N: Suprascapular nerve

Question 8

Infraspinatus

Answer 8

O: Infraspinous fossa

I: Greater tubercle

A: Laterally rotate humerus

N: Suprascapular nerve

Question 9

Teres Minor

Answer 9

O: Upper 2/3 of lateral border of scapula

I: Greater tubercle of the humerus

A: Laterally rotate the should (glenohumeral joint), adduct the shoulder, stabilize head of humerus in glenoid cavity

N: Axillary C5,C6

Question 10

Subscapularis

(anterior view)

Answer 10

O: Subscapular fossa

I: Lesser tubercle

A: Medially rotate humerus

N: Upper and lower subscapular nerves

Question 11

Teres Major

(lat’s little helper)

Answer 11

O: Lateral border of scapula

I: Intertubercular groove

A: Adduct, medially rotate and extend humerus

N: Lower subscapular nerve

Question 12

Pectoralis Major

Answer 12

O: Medial ½ clavicle, sternum and upper 6 costal cartilages

I: Bicipital groove (humerus)

A: Flex, adduct and medially rotate the humerus

N: Lateral and medial pectoral

Question 13

Pectoralis Minor

Answer 13

O: Ribs 3,4,5

I: Coracoid process of scapula

A: Protract, depress scapula, medial rotation

N: Medial pectoral

Question 14

Subclavius

Answer 14

O: 1st costal cartilage

I: Inferior groove of clavicle

A: Depress and stabilize clavicle

N: Nerve to subclavius

Question 15

Serratus anterior

Answer 15

O: Upper 8 ribs

I: Medial border of scapula

A: Protraction, laterally rotate the scapula

N: Long thoracic nerve