Mm of the Shoulder

Question 1

Trapezius

Answer 1

Origin: Occipital bone, Nuchal ligament; new structure, discuss, Spinous processes C7-T12

Insertion: Upper: Lateral 1/3 of clavicle and spine of the scapula

Middle and Lower: Spine of scapula

Action: Upper: Scapular elevation

**Fixed insertion actions: neck lateral flexion, rotation of the head to the contralateral side, neck extension**

Middle: Scapular retraction

Lower: Scapular Depression

Nerve: Cervical spinal nerves 2-4 and Cranial nerve XI; Accessory n or Spinal accessory n segments 2-4

Question 2

Pectoralis Minor

Answer 2

Origin: Ribs 2-5 (some sources may note ribs 3-5)

Insertion: Coracoid process of the scapula

Action: Scapular depression, scapular protraction

**Fixed insertion action: Elevation of ribs 2-5 (or 3-5)**

Nerve: Anterior thoracic n

Question 3

Serratus Anterior

Answer 3

Origin: Ribs 1-9 (some sources may note ribs 1-8)

Insertion: Anterior surface, medial border of the scapula

Action: Scapular protraction

Nerve: Long thoracic n

Question 4

Levator Scapulae

Answer 4

Origin: Transverse processes C1-C4

Insertion: Superior angle of the scapula

Action: Scapular elevation

**Fixed insertion action: Neck lateral flexion

Nerve: Dorsal Scapular n

Question 5

Rhomboid Minor and Major

Answer 5

Origin: Spinous processes C6-T4

Insertion: Medial border of the scapula

Action: Scapular elevation with retraction

Nerve: Dorsal scapular n

Question 6

Muscles that cause extension

Answer 6

Latissimus Dorsi

Teres Major

Deltoid​ (posterior)

Question 7

Muscles that cause flexion

Answer 7

Pectoralis Major

Deltoid (anterior)

Coracobrachialis

Question 8

Muscles that cause ADDuction

Answer 8

Pectoralis Major

Latissimus Dorsi

Teres Major

Coracobrachialis

Question 9

muscles that cause ABDuction

Answer 9

Deltoid (middle)

Supraspinatus

Question 10

Muscles that cause internal rotation

Answer 10

Pectoralis Major

Latissimus Dorsi

Deltoid (anerior)

Teres Major

Subscapularis

Question 11

Muscles that cause external rotation

Answer 11

Deltoid (posterior)

Teres Minor

Infraspinatus

Question 12

Muscles that increase the integrity/stability of the glenohumeral joint

Answer 12

Supraspinatus

Teres Minor

Infraspinatus

Subscapularis

Question 13

Muscles that elevate the scapular

Answer 13

Trapezius (upper)

Rhomboid Minor and Major

Levator Scapulae

Question 14

Muscles that retract the scapular

Answer 14

Trapezius (middle)

Rhomboid Minor and Major (with elevation)

Question 15

Muscles that depress the scapular

Answer 15

Trapezius (lower)

Pectoralis Minor

Question 16

muscles that protract the scapular

Answer 16

Pectoralis Minor

Serratus Anterior