Scapula and Shoulder Girdle

shoulder girdle bones

sternum

clavicle

scapula

humerus

sternum - bony land marks

clavicular notch

jugular/suprasternal notch

manubrium

body of sternum

xiphoid process

clavicle - bony landmarks/orientation

superior/anterior:

convex/flat surface

deltoid tubercle

inferior/posterior:

concave

conoid tubercle

groove for subclavius

trapezoid line

impression for costoclavicular ligament

sternal end = bump with vertical flat part

acromial end = flattened out

scapula - bony landmarks

lateral border (side of processes)

superior border

lateral border

inferior angle

anterior:

coracoid process is in front of acromial process

neck

subscapula fossa

posterior:

spine of scapula

supraspinous and infraspinous fossa

lateral:

glenoid cavity

acromion types

modified Bigliani Classification System:

type I-IV

acromion type I

flat - 12%

acromion type II

curved - 56%

considered most common type

acromion type III

hooked - 29%

associated with increased incidence of shoulder impingement → less space for tendons, arteries, etc.

acromion type IV

convex (upturned) - 3%

least common

surgical neck

surgical neck is where humeral head is replaced in surgery

it is an imaginary line

posterior humerus face bony landmarks

anatomical neck

humeral head

greater tuberosity

surgical neck

anterior humerus face bony landmarks

humeral head

anatomical neck

intertubercular groove

lesser tuberosity

greater tuberosity

deltoid tuberosity

shoulder girdle joints

sternoclavicular

acromioclavicular

glenohumeral

scapulothoracic

sternoclvicular joint

synovial saddle joint - convex/concave surfaces (different planes = different congruences)

three planes of motion

articulation between clavicle, manubrium, and 1st rib

poor congruence to mimic planer joint (behaves like ball-and-socket)

ligaments:

• anterior/posterior SCL

• interclavicular ligament

• costoclavicular ligament

articular disk

movements: depression/elevation

interclavicular ligament

holds clavicles together

posterior steronoclavical ligament

on posterior side

holds sternum and clavicle together

anterior sternoclavicular ligament

holds clavicle to anterior/superior portion of manubrium

costoclavicular ligament

connects clavicle to 1st rib

Articular disk of SC joint

forms two compartments

attached to SCLs and interclavicular ligament for stability

Acromioclavicular joint

planar joint

articulation between acromion process and clavicle

ligaments:

• acromioclavicular

• coracoacromial

• coracoclavicular

  • tapezoid (anterior and lateral bands0

  • conoid

little bit more mobility than SC joint

anterior and posterior movement during protraction and retraction

Glenohumeral Joint

ball and socket joint

articulation between glenoid fossa and humeral head

unequal proportion of surface area

• about ⅓ of humeral head contacting glenoid fossa (golf ball on a tee)

• = decreased stability & increased mobility

glenoid labrum

ligaments:

• capsular ligaments

glenoid labrum

fibrocartilage structure

attached to outer margins of glenoid fossa

deepens articulation to increase stability - dynamic and allows some more movement

often tears more due to extending out further and taking on more stress from humeral head

Capsular ligaments - GH joint

merge to encircle entire joint around humeral head

attached:

• medially beyond the glenoid labrum (neck)

• laterally below anatomical neck

coracohumeral ligament

transverse humeral ligament - holds biceps tendon in place

glenohumeral ligaments - superior, middle, inferior

GH joint posterior capsule

supported by posterior band of IGHL

important in stabilizing from anterior dislocation

contracture results in GH IR deficit (GIRD)

GH movements - sagittal plane

flexion

extension

hyperextension

GH movements - Frontal plane

abduction

adduction

GH movements - transverse plane

IR

ER

horizontal abduction

horizontal adduction

scapulothoracic joint

pseudo-joint/conceptual

lacks bony articulation

slides/glides along posterolateral thoracic wall

scapular motion facilitated by ROM of other joints in the shoulder girdle

does not have ligamentous support - relies on dynamic stabilizers

movements:

• elevation/depression

• upward/downward rotation

• protraction/abduction

• retraction/adduction

role of scapula

connects arm to trunk of body

maintains dynamic stability with controlled mobility at the GHJ

proximal to distal transfer of energy

role of scapula: 1. connects arm to trunk of body

provides glenoid fossa for glenohumeral ball and socket joint

allows for movements of the upper extremity (dynamic stability)

role of scapula: 2. maintains dynamic stability with controlled mobility

synergistic co-contractions (force couples)

length/tension relationships for muscles

no isolated movements

role of scapula: 3. proximal to distal transfer of energy

force travels from the legs and trunk to the arm and hand

aids in deceleration in throwing motion (dissipation of energy) - muscles of scapula

scapulothoracic movements - elevation/depression muscles

elevation:

• upper trapezius

• rhomboids

• levator scapula

depression:

• lower trapezius

• lower serratus anterior

scapulothoracic movements - upwards/downward rotation muscles

upward rotation:

• serratus anterior

• upper trapezius

• lower trapezius

downward rotation:

• rhomboids

• levator scapulae

scapulothoracic movements - abduction/adduction muscles

abduction:

• serratus anterior

adduction:

• trapezius

• rhomboids

scapulohumeral rhythm - purpose

maximize ROM

static and dynamic stabilizers work to create optimal length-tension relationship for movement to occur

scapulohumeral rhythm - function

the scapula and humerus move at a 1:2 ration (scapula:humerus)

approaches 1:1 ratio within midrange (60^o-90^o)

ex. arm abducted to 180^o will result in 60^o of motion via scapula/STJ and 120^o via humerus/GHJ

end range is mostly scapular movements

scapulohumeral rhythm: phase 1

30^o elevation

humerus: 30^o abduction

clavicle: 0^o-5^o elevation

scapula: minimal movement medially

scapulohumeral rhythm: phase 2

90^o elevation

humerus: 40^o abduction (up to 90^o)

scapula: 20^o lateral rotation

clavicle: 15^o elevation

scapulohumeral rhythm: phase 3

90^o-180^o elevation

humerus: 60^o abduction, 90^o lateral rotation

scapula: 30^o lateral rotation

clavicle: 30^o-50^o posterior rotation, 15^o elevation

intramuscular spaces if scapular region

upper triangular region

quadrangular space

lower triangular space

scapulohumeral muscle grouping

attaches humerus to scapula

deltoid

teres major

rotator cuff muscles

coracobrachialis

axioscapular muscle groupings

attaches scapula to the trunk

trapezius

rhomboid minor/major

serratus anterior

levator scapula

axiohumeral muscle grouping

attaches humerus to trunk

pectoralis major/minor

latissimus dorsi

Axilla contents

axillary vein and artery

brachial plexus

lymph nodes

fat

axillary region - apex

upper border of scap, clavicle, and 1st rib

inlet to the cervico axillary canal

axillary region - base

skin, subcutaneous tissue and fat

outlet to the cervico axillary canal

axillary region anterior border

pectoralis major/minor

axillary fat

axillary region lateral border

intertubercular sulcus

(humerus)

axillary region medial border

serratus anterior

thoracic wall

ribcage

axillary region posterior border

scapularis (?)

teres major

latissimus dorsi

scapula

axillary musculature layers

superficial extrinsic

deep extrinsic

intrinsic

axillary muscles - superfical extrinsic

trapezius

latissimus dorsi

axillary muscles - deep extrinsic

levator scapula

rhomboid major/minor

serratus anterior

axillary muscles - intrinsic

deltoid

teres major/minor

supraspinatus

infraspinatus

subscapularis

deltoid - OINA

O:

• lateral ⅓ clavicle

• acromion process

• spine of scapula

I:

• deltoid tuberosity of humerus

N:

• axillary nerve

A:

• anterior fibers:

  • shoulder flex

  • IR

  • horizontal adduction

• posterior fibers:

  • shoulder extension

  • ER

  • horizontal abduction

• all fibers - shoulder abduction

teres major OINA

O:

• posterior surface of inferior angle of scapula

I:

• medial lip of intertubercular groove of humerus

N:

• adducts arm

• IR arm

A:

• lower subscapular nerve - C5, C6

rotator cuff muscles

SITS

supraspinatus

infraspinatus

teres minor

subscapularis

supraspinatus OINA

O:

• supraspinous fossa of scapula

I:

• superior facet of greater tubercle of humerus

N:

• suprascapular nerve - C4-C6

A:

• initiates and assists deltoid in abduction

• acts with RC movements

infraspinatus OINA

O:

• infraspinous fossa of scapula

I:

• middle facet of greater tubercle of humerus

N:

• suprascapular nerve - C5, C6

A:

• ER arm

• acts with RC movements

Teres minor OINA

O:

• middle part of lateral border of scapula

I:

• inferior facet of greater tubercle of humerus

N:

• axillary nerve - C5, C6

A:

• ER arm

• acts with RC movements

Subscapularis OINA

O:

• subscapular fossa

I:

• lesser tubercle of humerus

N:

• upper and lower subscapular nerve - C5-C7

A:

• IR arm

• acts with RC movements

brachial plexus

Roots: 5

Trunks: 3

Divisions:

• 3 anterior

• 3 posterior

Cords: 3

branches: 5

shoulder pain - causes

global diffuse pain due to close proximity of structures to each other and continual movement

SLAP tear

frozen shoulder

abnormal AC joint

shoulder OA

biceps tendinitis

calcific tendonitis

rotator cuff tear

scapular dyskinesis

loss of motor control of the scapulohemeral motion

normal scapular position is altered

lack of coordinated activation patterns in the scapula stabilizing movements

often found in shoulder impingement pts'

SICK scapular syndrome (causes)

= altered movement of the shoulder girdle

established association to shoulder pathologies

SICK scapular syndrome

S - scapula malpositioning

I - inferior medial roder prominence (off the rib cage and tightness of muscles)

C - coracoid paina nd malposition

K - kinesis abnormalities of the scap

scapular dyskinesis - type I

inferior angle

scapular dyskinesis - type II

medial border/winged scapula

scapular dyskinesis - type III

superomedial border - very dysfunctional

traumatic fx

fx of surgical neck - ORIF

avulsion fx of greater tubercle - ORIF

peripheral nerve injuries

anterior and posterior dislocations

shoulder separation

locations of nerves and injuries

fx of surgical neck may injury axillary nerve (as it wraps around the humeral head)

fx of humeral body in region of radial groove may injure radial nerve

distal humeral fx may injure medial nerve

fx in region of medial epicondyle may injure ulnar nerve

dislocations - general

humeral head can dislocate: inferiorly, anteriorly, & posteriorly

• not superior due to acromion process

Direction depends on force application

occurs most frequently in young adults and athletes - traumatically too

anterior dislocation

head of humerus is driven anterior inferiorly where capsule is weakest

fibrous capsule and glenoid labrum may be stripped from anterior aspect of glenoid

flexor and abductor muscle usually pull humeral head into a subcoracoid postion

axillary nerve may be injured

apprehension test

test for glenohumeral instability vs anterior dislocation

go into ER to put stretch on anterior capsule

watch pt facial expression

Hill-sachs lesions

posterolateral humeral head compression fx

typically secondary to recurrent anterior shoulder dislocations as the humeral head comes to rest against the anteroinferior part of the glenoid

shoulder separation: moi/degrees

most common MOI is a fall on the tip of the shoulder

injury to the AC ligament and CC ligament

1st degree - isolated to AC ligament

2nd degree - AC ligament and stretch of CC ligaments

3rd degree - Tear of all three ligaments, AC and both CC heads

(CC= coracoid clavicular)

rotator cuff pathology

repetitive use of the UE, sudden strain/forces, falls

can be degenerative in nature with older pt

• why a good hx is needed

involves the musculotendinous rotator cuff and/or long head of biceps tendon

recurrent inflammation of RC tendons can lead to tears

Signs/Sx:

• pain

• lost of motion most commonly ABD and ER

  • ABD - supraspinatus involved

  • ER - teres minor & infraspinatus involved

• decreased RC strength

• loss of functional mobility

shoulder impingement (syndrome)

reduced sub-acromial space - supraspinatus tendon and bursa squished

more symptoms with abduction because humeral head is moving superiorly

px in middle of ROM

can result in rotator cuff tear

SLAP tear: signs/sx

superior labral tear from anterior to posterior

signs/sx:

• locking, popping, catching, grinding, less stable feeling

• px with movement of shoulder or holding certain positions

• px with lifting objects → especially overhead; still do it becuase other msucles can still move

• decrease in shoulder strength

• feeling the shoulder will pop out of joint

• decreased ROM

• pitchers may notice a decrease in their throw velocity or the feeling of having a “dead arm” after pitching

4 types

slap tear type I

frayed cartilag at the edge of labrum

slap tear type II

labrum tears away from glenoid cavity

slap tear type III

bucket handle section tears away from glenoid cavity

slap tear type IV

slap lesion extends and tears the biceps tendon

adhesive capsulitis

aka frozen shoulder

adhesive fibrosis and scarring within the inflamed joint capsule of the GH joint, RC, subacromial bursa and deltoid

common in females 40-60 y/o or with diabetes/metabolic disorders

often insidious onset - can be caused by prior injuries to shoulder (dislocations, fx, tendonitis, RC)

capsular pattern with:

• loss of ROM

• px

• stiffness

• loss of functional mobility

3 phases: freezing, frozen, thawing

Apley’s scratch test

quick check of AROM

1) horizontal adduction with internal rotation (behind the back)

2) abduction with external rotation (overhead)

3) adduction with internal rotation (across chest)

for frozen shoulder (?)

bursitis

inflammation of the bursa(s) in shoulder

infraserratus bursa

supraserratus bursa

trapezoid bursa

infaserratus bursa

subscaular bursa

subdeltoid bursa

subcoracoid bursa

subacromial bursa

shoulder replacement surgery

replacement of shoulder with artificial parts

total shoulder arthroplasty vs reverse shoulder arthroplasty

performed on pt with severe px, loss of UE function from arthritis, fx, RA, exstensive RC/Mm wear and tear

extensive rehab is needed

reverse shoulder arthroplasty

glenoid sphere = convex surfacce

humeral cap = concave surface

flips concave/convex surfaces

increase ROM compared to total SA