Pt 517: Functional Anatomy Of The Shoulder Complex

Front 1

Bones of the shoulder complex

Back 1

Sternum, clavicle, scapula and humerus

Front 2

Sternoclavicular joint

joint mechanic classification

Back 2

triaxial

Front 3

Sternoclavicular joint

shape

Back 3

saddle

clavicle is convex in a superior/inferior direction and concave in a anterior/posterior direction

Front 4

Sternoclavicular joint CPP and LPP

Back 4

CPP- full elevation

LPP- arm at the side

Front 5

Elevation of SC joint

Back 5

Rotation in the frontal plane around an Anterior posterior axis

The convex end of the clavicle rolls superior and glides inferior on the sternum

Maximum elevation- 45°

Front 6

Depression of SC joint

Back 6

rotation in the frontal plane around an anterior posterior axis

The convex end of the clavicle rolls inferior and glides superior on the sternum

Maximum depression 10°

Front 7

Protraction of SC joint

Back 7

occurs ~parallel to the horizontal plane about a vertical axis

the concave surface of the clavicle rolls and glides anterior on the sternum

amount of motion: 15-30°

Front 8

Retraction of the SC joint

Back 8

occurs ~ parallel to the horizontal plane about a vertical axis

The concave surface of the clavicle rolls and glides posterior on the sternum

amount of motion 15-30°

Front 9

Rotation of the SC joint

Back 9

occurs around a longitudinal axis

when the arm is elevated the superior clavicle rotates posteriorly due to tension on the coracoclavicular ligament

rotates 20-35°

Front 10

Anterior posterior sternoclavicular ligaments

Back 10

reinforces the capsule, limits anterior and posterior movement of clavicle

Front 11

interclavicular ligaments

Back 11

Cross superior aspect of SC joint

attach to medial ends of clavicle

provide superior joint stability

Front 12

Costoclavicular ligaments

Back 12

attach first rib to inferior surface of clavicle

limit elevation of the clavicle on the first rib

Front 13

Articular disc of SC joint

Back 13

fibrocartilage that divides the joint into medial and lateral cavities

function: shock absorption, increases joint congruency, provides stability

Front 14

Stabilizing muscles of the SC joint

Back 14

sternocleidomastoid, sternothyroid and sternohyoid

Front 15

Acromioclavicular joint shape

Back 15

Plane synovial joint with three degrees of freedom, can be concave or convex

Front 16

Acromioclavicular joint CPP and LPP

Back 16

CPP: 90 degrees abduction

LPP: arm at the side

Front 17

UPward rotation of AC joint

Back 17

• the accordion moves up and outward in relation to the clavicle

• allows upward rotation of the scapula

• up to 30° present with arm elevation

Front 18

Downward rotation of the AC joint

Back 18

the accordion moves down and inward in relation to the clavicle in an anterior posterior axis.

allows downward rotation of the scapula

Front 19

Transverse plane movements of the AC joint

Back 19

Occurs around a vertical axis

allows the medial border of the scapula to get closer or further away from the thorax

Front 20

Sagittal plane movements of the AC join

Back 20

occurs around a medial-lateral axis

allows the inferior angle of the scapula to tip away or toward the thorax

anterior and posterior tilting

Front 21

Arthrokinematics of AC joint

Back 21

unpredictable due to the variability in the shape of the articular surfaces

Acromion is most often concave and therefore glides and rolls in the same direction

Front 22

Superior and inferior acromioclavicular ligaments

Back 22

reinforce joint capsule

Front 23

coracoclavicular ligaments

Back 23

• control vertical joint stability

• limit upward rotation

• limit medial displacement

• create longitudinal rotation of clavicle

• trapezoid- lateral portion

• conoid- medial portion

Front 24

Scapulothoracic joint

Back 24

not a true joint

the scapula is typically positioned between the 2nd and 7th ribs and is ~6 cm from the spinous processes

Front 25

Elevation of the ST joint

Back 25

Scapula is gliding superiorly

prime movers: upper traps, levator scapulae, rhomboid minor, rhomboid major

Front 26

Depression of the ST joint

Back 26

scapula is gliding inferiorly

prime movers: subclavius, pectoralis minor, pectorals major (lower fibers), lower traps, serrates anterior (lower fibers) and latissimus dorsi ( lower fibers)

Front 27

Retraction at the ST joint

Back 27

scapula glides medially on the thorax

prime movers: rhomboid minor, rhomboid major, middle fibers of the traps, latissimus dorsi (upper fibers)

Front 28

Protraction at the ST joint

Back 28

scapula glides laterally on the thorax

prime movers- pec minor, pec major and serrates anterior

Front 29

Upward rotation at the ST joint

Back 29

interior angle moves away from the vertebral column

prime movers: trapezius (upper and lower part), serrates anterior

60• of scapular rotation available at ST joint

Front 30

Downward rotation at the ST joint

Back 30

inferior angle moves closer to the vertebral column

prime movers: levator scapulae, rhomboid major and minor, pectorals major (lower fibers), pectorals minor, latissimus dorsi

Front 31

Function of the ST joint

Back 31

orients the gleaned fossa for optimal contact with the head of the humerus

adds range to arm elevation

provides a stable base for GH movements

Front 32

Upper trapezius

Back 32

origin: occipital bone, cervical spinous processes via nuchal ligament

insertion: lateral 1/3 of clavicle, acromion

Actions at scapula: elevation, retraction, upward rotation

Front 33

Middle Trapezius

Back 33

Origin: spinous processes T1-T5

Insertion: acromion and spine of scapula

actions at scapula: retraction

Front 34

Lower Trapezius

Back 34

Origin: spinous processes T6-T12

Insertion: root of the spine of the scapula

Actions at scapula: depression, retraction, upward rotation of scapula

Front 35

Levator Scapulae

Back 35

action: elevation, downward rotation

Front 36

Rhomboids

Back 36

Action: elevation, retraction, downward rotation

Front 37

Serratus anterior

Back 37

action: protraction, depression, upward rotation

Front 38

Pectoralis Major

Back 38

Insertion: lateral lip of the inter tubercular groove

Action: GH flexion (clav), GH extension (sterno), GH adduction, GH medial rotation, GH horiz adduction, scapular depression, scapular protraction

Front 39

Pectoralis Minor

Back 39

Action: scapular depression, scapular protraction, scapular downward rotation