Back and Shoulder

What is the vertebral column made of?

vertebrae and intervertebral discs

What is vertebral column part of?

axial skeleton

What are 4 functions of vertebral column?

1. protection
2. support body weight superior to pelvis
3. axis for body and head
4. posture and locomotion

What 4 movements do the vertebral column involve?

1. flexion - bend forward
2. extension - lean back
3. lateral flexion - side bend
4. rotation

What are the two curvatures of the vertebral column and which areas spinal regions are involved in each?

1. kyphotic (primary) - thoracic and sacral regions
2. lordotic (secondary) - cervical and lumbar regions

What are the primary curvatures?

* formed during fetal period
* thoracic and sacral kyphoses

What are the secondary curvatures?

* formed as a result of extension from flexed fetal position
* cervical and lumbar lordoses

What is the vertebral body of a vertebrae?

massive anterior part

What are pedicles of a vertebrae?

short processes projecting from vertebral body

What are laminae of a vertebrae?

flat plates that connect to pedicles; unite in midline

What are spinous processes of a vertebrae?

posterior projection at laminal junction

What are transverse processes of a vertebrae?

bilateral posterolateral projections from junctions of pedicles/laminae

What does the supraspinou sligament connect?

connects spinal processes from C7 to sacrum and it merges superiorly with the nuchal ligament

What is the extent of the nuchal ligament?

from the external occipital protuberance and foramen magnum to the spinal processes of the cervical vertebrae

What is the purpose of the nuchal ligament?

accomodates shortness and depth of cervical vertebrae and provides attachment point for muscles that attach to spinous processes

What is the term for sway back?

excessive lordosis

What are three causes of excessive lordosis?

1. weakened trunk musculature
2. obesity
3. pregnancy

What is the term for hunchback?

excessive kyphosis

What is the cause of excessive kyphosis?

erosion of anterior part of one or more vertebrae

What are two effects of excessive kyphosis?

1. loss of height
2. limits thoracic capcity

What is scoliosis?

abnormal lateral curvature of spine accompanied by rotation of vertebrae

What is spinous process rotation in regard to scoliosis?

SPs rotate toward the cavity of abnormal curvature

What do the ribs do in regard to scoliosis?

protrude to side of increased convexity

What are the layers of the extrinsic back?

superficial and intermediate layers

What is the function of the extrinsic back?

control limb and respiratory movements

What innervates the extrinsic back?

ventral rami; exception is trapezius (CN XI)

What are the layers of the intrinsic back?

superficial, intermediate, and deep layers

What is the function of the intrinsic back?

act on the vertebral column

What are the 4 superficial extrinsic back muscles?

1. trapezius
2. levator scapulae
3. latissimus dorsi
4. rhomboid major and minor

What do the superficial extrinsic back muscles connect?

connect the axial skeleton with superior appendicular skeleton

What do the superficial extrinsic back muscles move?

scapula and humerus

What innervates the superficial extrinsic back muscles?

ventral rami of the cervical nerves, with the exception of the trapezius, which gets innervates by cranial nerve XI (accessory)

What are the three parts of the trapezius?

1. upper - descending from skull and attaches to clavicle and scapula
2. middle - horizontal
3. lower - ascending from the vertebral column

What is the origin of trapezius muscle?

* external occipital protuberance


* lig nuchae
* C7-T12 spinous processes

What is the insertion of trapezius?

lateral 1/3 clavicle, acromion, spine of scapula

What are the 4 movements of the trapezius?

1. retraction - middle fibers
2. upward rotation - upper fibers pull superiorly, lower fibers pull inferiorly
3. depression - lower fibers pull inferiorly
4. elevation - upper fibers

What innervates trapezius?

accessory nerve (CN XI)

Latissimus dorsi passes medial to what?

humerus

What is the origin of lattisimus dorsi?

* T7-12 spinous processes
* thoracolumbar fascia
* iliac crest
* inferior 3-4 ribs

What is the insertion of latissimus dorsi?

floor of intertubercular groove of humerus

What are the 3 movements of latissimus dorsi?

1. medial rotation - bring in toward midline
2. extension - posterior
3. adduction - coming toward the body

All of these are on the humerus

What innervates latissimus dorsi?

thoracodorsal nerve (C6, C7, C8)

What is the location of levator scapulae?

* deep to trapezius
* look for the superior angle of scapula

What is the origin of levator scapulae?

posterior aspect of C1-C4 transverse processes

What is the insertion of levator scapulae?

superior angle of scapula

What are the two action of the levator scapulae?

1. elevation of scapula
2. stabilization of scapula

What innervates levator scapulae?

dorsal scapular nerve (C5)

What is the location of rhomboid major?

deep to trapezius, inferior to rhomboid minor

What is the origin of rhomboid major?

T2-T5 spinous processes

What is the insertion of rhomboid major?

medial border of scapula below spine

What are the three action of the rhomboid major?

retraction, elevation, and downward rotation of the scapula

What innervates rhomboid major?

dorsal scapular nerve (C5)

What is the location of rhomboid minor?

deep to trapezius, superior to rhomboid major

What is the origin of rhomboid minor?

C7-T1 spinous processes; lig nuchae

What is the insertion of rhomboid minor?

medial border of scapula at spine

What are the three actions of rhomboid minor?

retraction, elevation, downward rotation of scapula

What innervates rhomboid minor?

dorsal scapular nerve (C5)

What is the triangle of auscultation?

small, triangular gap near the inferior angle of scapula

What are the three borders of the triangle of auscultation?

1. medial border of scapula
2. latissimus dorsi muscle
3. trapezius muscle

What is the clinical importance of the triangle of auscultation?

good area to listen to the posterior segments of the lung

What is the origin of the transverse cervical artery?

thyrocervical trunk

What is the location of the transverse cervical artery?

on the deep surface of trapezius muscle

What does transverse cervical artery run with?

runs with CN XI on deep to trapezius muscle

What is the origin of the dorsal scapular artery?

subclavian artery

What does the dorsal scapular artery run with?

dorsal scapular nerve

What is the origin of the thoracodorsal artery?

subscapular artery

What does the thoracodorsal artery run with?

runs with thoracodorsal nerve

Where does CN XI (accessory nerve) exit and descend?

Accessory nerve exits into the jugular formane in the skull and descends into the neck

What does the accessory nerve innervate?

trapezius muscle

What is the origin of the thoracodorsal nerve?

posterior cord of brachial plexus

What rami are involved with thoracodorsal nerve?

C6-C8

What does the thoracodorsal nerve innervate?

latissimus dorsi muscle

What is the origin of the dorsal scapular nerve?

C5 ramus of brachial plexus

What artery runs with the dorsal scapular nerve?

dorsal scapular artery

What does the dorsal scapular nerve innervate?

rhomboid major muscle, rhomboid minor muscle, and levator scapulae muscle

In the scapular region, what are the 6 scapulohumeral muscles?

1. deltoid muscle
2. supraspinatus muscle
3. infraspinatus muscle
4. teres major muscle
5. teres minor muscle
6. subscapularis muscle - not pictured here because it sits on the scapula anteriorly

What does the deltoid form?

rounded contour of the shoulder

What are the three muscle divisions of the deltoid?

anterior, middle, and posterior fibers - the parts can act separately or as a whole

What is the origin of the deltoid?

lateral 1/3 of clavicle, acromion, spine of scapula

Where does the deltoid insert?

deltoid tuberosity

What are the three actions of the deltoid?

1. all fibers do ABD (15-90 degrees) of humerus
2. anterior - flexion, medial rotation of humerus
3. posterior - extension, lateral rotation of humerus

What innervates the deltoid muscle?

axillary nerve (C5, C6)

What does teres major attach to?

Teres major passes medial to the humerus where it attaches anteriorly.

Where is teres major relative to minor?

Teres major is found inferior the teres minor

Teres major is not what?

Teres major is not a rotator cuff muscle, but teres minor is

What is the origin of teres major?

inferior angle of posterior scapula

What is the insertion of teres major?

medial lip of intertubercular groove of the humerus

What are the actions of teres major?

ADD and medial rotation of humerus

What innervates teres major?

lower subscapular nerve (C5, C6)

Where does supraspinatus lie?

above the scapular spine

What does supraspinatus help form?

helps form the musculotendinous “cuff” around the glenohumeral joint

What is the the only rotator cuff muscle that does not rotate the humerus?

supraspinatus

What is the origin of supraspinatus?

supraspinous fossa

What is the insertion of supraspinatus?

superior facet of greater tubercle of the humerus

What is the action of supraspinatus?

initates ABD of humerus (first 15 degrees)

What innervates supraspinatus?

suprascapular nerve (C5, C6)

What does the infraspinatus help form?

the musculotendinous “cuff” around the glenohumeral joint

What is the origin of the infraspinatus?

infraspinous fossa

What is the insertion of the infraspinatus?

middle facet of greater tubercle of the humerus

What are the actions of infraspinatus?

1. lateral rotation of humerus (primary function)
2. aids in ADD of humerus