Muscles

Question 1

Subclavius

Answer 1

Position: inferior to clavicle
Origin: costochondral junction of first rib
Insertion: inferior surface of clavicle
Action: fixates the clavicle
: depresses lateral end of clavicle (pulls shoulder inferoanteriorly)
Innervation: Subclavian nerve (C5-6)

Question 2

Pectoralis Minor

Answer 2

Position: deep to pec major
Origin: Ribs 3-5 + costal cartilages
Insertion: Coracoid process
Action: depresses scapula vs resistance
           : medial rotates scapula
           : protracts scapula
           : assists forced inspiration
Innervation: Medial pectoral nerve (C8)

Question 3

Serratus Anterior

Answer 3

Position: deep to latissimus dorsi, covering upper part of side of thorax, between scapula and ribs
Origin: outer surfaces of upper 8-9 ribs + intercostal fascia
Insertion: medial costal surface of scapula
Action: depresses scapula vs resistance
: laterally rotates scapula
: protracts scapula
Innervation: Long thoracic nerve (C5-7)

Question 4

Levator Scapulae

Answer 4

Origin: transverse processes of C1-4
Insertion: superior portion of medial border of scapula
Action: elevation
           : medial rotation
Innervation: Dorsal scapula nerve (C4-5)

Question 5

Rhomboid major

Answer 5

Origin: spinous processes of T2-5 
          : supraspinous ligament
Insertion: medial border of scapula - inferior to scapula spine
Action: retraction
           : medial rotation
Innervation: Dorsal scapula nerve (C4-5)

Question 6

Rhomboid Minor

Answer 6

Origin: spinous processes of C7-T1
          : supraspinous ligament
Insertion: medial border of scapula spine
Action: retraction
           : medial rotation of scapula
Innervation: Dorsal scapula nerve C4-5

Question 7

Trapezius

Answer 7

Position: Posterior, superficial aspect of neck, shoulder and upper back
Origin: Superior Nuchal line + external occipital protuberance
: ligamentum nuchae
: spinous processes of C7-T12
: supraspinous ligament
Insertion: lateral 1/3 of clavicle (upper)
: acromion + spine of scapula (middle)
: medial end of scapula spine (lower)
Actions: Upper - neck extension (bilateral)
- neck lateral flexion (ipsilateral)
- elevation of scapulae
- lateral rotation of scapula (with lower)
: Middle - retraction of scapula
: Lower - depression vs resistance
- lateral rotation (with upper)
Innervation: Accessory nerve (xi cranial) C3-4

Question 8

functional activity of trapezius

Answer 8

> steadies scapula and clavicle (upper)
- vs gravity or weight in hand
> provides fixation
- controls head position
> lateral rotation of scapula 
- reaching overhead
> retraction of scapula
- good posture 
> depression of scapula vs resistance
- sit to stand hands on chair