Superficial Back

bones and bony landmarks

- cervical spine: spinous process & transverse process

- clavicle

- scapula

- scapular spine

- acromion process of scapula

- glenoid fossa of scapula

- inferior angle of scapula

- superior angle of scapula

- intertubercular groove of humerus

transverse process

- on either side of the spinous processes

- need to reflect the trapezius to see

cervical vertebrae

- necessary to shoulder function

acromium

articulates with the clavicle

inferior angle

lowest point of the scapula

superior angle

responsible for most scapular movement

intertubercular groove

front of the humerus

scapular movements

unstable ---> held in place by muscle tone

upward/lateral rotation of the scapula

- rotating the inferior angle superiorly

- when you abduct the shoulder

downward/medial rotation of the scapula

- rotating the inferior angle inferiorly

- return arm to neutral

retraction of the scapula (adduction)

- drawing the scapula posteriorly

- bring the medial edges of the scapula together

protraction of the scapula (abduction)

- pulling the scapula anteriorly off of the rib cage

- Forward reaching

Ex. Butteryfly

The superficial back muscles create:

Create the scapulothoracic joint

stabilize the scapula

stabilize cervical posture

trapezius

- base of scull to T-12

- diamond

- savior of the upper limb

- drives overhead movement

- retractors

trapezius upper fibers

elevate the shoulder (shoulder shrug), assist lower fibers in upward/lateral rotation of the scapula

lateral 1/3 of the clavicle

What is the insertion of the trapezius upper fibers?

trapezius middle fibers

retraction of scapula ("squaring the shoulders")

acromion process

What is the insertion of the trapezius middle fibers?

trapezius lower fibers

assist upper fibers in upward/lateral rotation of the scapula

spine of scapula

What is the insertion of the trapezius lower fibers?

spinal accessory nerve (CN XI)

What innervates the trapezius?

trapezius

spinal cord injuries spare this and allow upper limb function

What muscle doe not help with scapula stabilization?

Latissimus Dorsi

latissimus dorsi

- extends shoulder, medial/internal rotation of shoulder, & shoulder adduction

- strongest shoulder extensor

- "swimmer's muscle"

- covers almost entire ribcage

intertubercular groove of humerus

What is the insertion of the latissimus dorsi?

thoracodorsal nerve (branch of the brachial plexus)

What innervates the latissimus dorsi?

1) Iatrogenic

2) Crutches that compress the n.

What are injuries to the thoracodorsal n.?

scapulothoracic joint

- stabilize the scapula

- stabilize the cervical posture

- connect the vertical part of the scapula to the spine

forward head posture

A weakened scapulothoracic joint results in what?

levator scapulae

elevates scapula

superior angle of scapula

What is the insertion of the levator scapulae?

dorsal scapular nerve

What is the innervation of the levator scapulae?

rhomboid mass

Consists of the Rhomboid major and minor mm

- scapular retraction

- runs medial to border of scapula

- weak in most people

vertebral/medial border of scapula

What is the insertion of the rhomboid mass?

dorsal scapular nerve

What is the innervation of the rhomboid mass?

deltoid

- As a single mass, this muscle abducts the shoulder

- shoulder stabilizer

- works with the trap in overhead activities

anterior head of the deltoid

flexes shoulder

posterior head of the deltoid

also extends the shoulder

clavicle

What is the origin of the anterior deltoid head?

acromion process

What is the origin of the middle deltoid head?

spine of the scapula

What is the origin of the posterior deltoid head?

deltoid tuberosity of humerus

What is the insertion of the deltoid?

axillary nerve

What is the innervation of the deltoid?

axillary nerve

- lots of issues

- goes into deltoid

- need to stay away giving intramuscular injections, piercing takes away all deltoid function

axillary neuropathy

- results in deltoid atrophy unilaterally

- signs of injury: deltoid atrophy, paresthesia of deltoid

serratus anterior

- protracts the scapula

- The primary scapular stabilizer

- starts as fasicles from ribs, sweeps posteriorly, goes under the scapula

ribs 1-8

What is the origin of the serratus anterior?

vertebral border & inferior angle of scapula

What is the insertion of the serratus anterior?

long thoracic nerve

What is the innervation of the serratus anterior?

winged scapula

What is the clinical correlate of the serratus anterior?

long thoracic nerve

- damage to this nerve results in a "winged scapula"

axillary nerve

sensation to skin over deltoid muscle

triangle of auscultation

area associated with the superficial back where heart and lungs sounds are the clearest

lower fibers of the trapezius muscle

What is the medial border of the triangle of auscultation?

vertebral border of scapula

What is the lateral border of the triangle of auscultation?

latissimus dorsi muscle

What is the inferior border of the triangle of auscultation?

6th and 7th rib

What is the floor of the triangle of auscultation?

Apex of lower lobe of both lungs

What lies beneath this triangle?

lumbar triangle

area associated with the superficial back where bowel sounds are the clearest

latissimus dorsi muscle

What is the medial border of the lumbar triangle?

external abdominal oblique muscle

What is the lateral border of the lumbar triangle?

iliac crest

What is the inferior border of the lumbar triangle?

Spinal accessory n CN XI (11)

Cranial n

Motor to the trapezius (and sternocleidomastoid m)

Dorsal scapular n.

branch of brachial plexus

Motor to levator scapulae and rhomboid mass

Thoracodorsal n.

branch of brachial plexus

Motor to latissimus dorsi m.

Long thoracic n.

branch of brachial plexus

motor to serratus anterior m.

damage results in winges scapula

Axillary n.

branch of brachial plexus

Motor to deltoid muscle (and teres minor m)

Sensation to skin over deltoid m.

Danger zone

intramuscular injections into the deltoid muscle