Muscles of Back, Chest and Shoulder

Question 1

Trapezius

Answer 1

• origin: external occipital protuberance and spinous processes of vertebrae to T12
• insertion: scapular spine and acromion, distal clavicle
• action: elevate, depress, adduct and superiorly rotate scapula

Question 2

Latissimus Dorsi

Answer 2

• origin: spinous processes of T7-sacrum, posterior iliac crest
• insertion: intertubercular groove of humerus
• action: extends, adducts and medially rotates arm

Question 3

Teres Major

Answer 3

• origin: inferior angle of scapula
• insertion: intertubercular groove of humerus
• action: extends, adducts and medially rotates arm

Question 4

Rhomboid (minor and major)

Answer 4

• origin: spinous processes of C7-T5
• insertion: vertebral (medial) border of scapula
• action: adduct (retract) and inferiorly rotate scapula

Question 5

Levator Scapulae

Answer 5

• origin: transverse processes of cervical vertebrae
• insertion: superior angle of scapula
  action: elevate and inferiorly rotate scapula

Question 6

Serratus Posterior Superior

Answer 6

• origin: spinous process of C7-T3
• insertion: ribs 2-5
• action: assist with inhalation

Question 7

Serratus Posterior Inferior

Answer 7

• origin: spinous processes of T11-L2
• insertion: ribs 8-12
• action: assist with exhalation (forced)

Question 8

Erector Spinae

Answer 8

spinalis, longissimus, and iliocostalis

• origin: sacrum and ilium
• insertion: spinous processes (spinalis), transverse processes (longissimus) and ribs (iliocostalis)
• action: extend spine

Question 9

Multifidus

Answer 9

deepest

• origin: transverse processes
• insertion: spinous processes 2-4 segments above origin
• action: contralateral rotation of spine

Question 10

Deltoid

Answer 10

• origin: scapular spine and acromion, distal clavicle
• insertion: deltoid tuberosity of humerus
• action: abducts arm

Question 11

Pectoralis Major

Answer 11

• origin: sternum and clavicle
• insertion: intertubercular groove of humerus
• action: flexes, adducts and medially rotates the arm (roundhouse punch)

Question 12

Pectoralis Minor

Answer 12

• origin: ribs 3-5
• insertion: coracoid process
• action: protracts scapula

Question 13

Serratus Anterior

Answer 13

• origin: ribs 1-8
• insertion: vertebral border of scapula
• action: protract and superiorly rotate scapula

Question 14

Rotator Cuff Muscles

Answer 14

SITS
Supraspinatus
Infraspinatus
Teres minor
Subscapularis

Question 15

Supraspinatus

Answer 15

• origin: supraspinous fossa of scapula
• insertion: greater tubercles of humerus
• action: abducts arm

Question 16

Infraspinatus

Answer 16

• origin: infraspinatus fossa of scapula
• insertion: greater tubercle of humerus
• action: laterally (externally) rotate arm

Question 17

Teres Minor

Answer 17

• origin: axillary border of scapula
• insertion: greater tubercle of humerus
• action: laterally (externally) rotates arm

Question 18

Subscapularis

Answer 18

• origin: subscapular fossa
• insertion: lesser tubercle
• action: medially (internally) rotate arm