Shoulder Girdle_2019 (copy)

Shoulder complex

scapula, clavicle, sternum, humerus, and rib cage

shoulder complex joints

SC, AC, GH, scapulothoracic articulation

Shoulder girdle

composed of clavicle and scapula

Shoulder girdle actions

Elevation/depression

Abd/Adduction

medial/lateral rotation

horizontal Abd/ Add

Glenohumeral joint

shoulder joint consists of the scapula and the humerus

Glenohumeral joint actions

Flex/Ext/HTN

Abd/Add

Medial/lateral rotation

horizontal abd/add

Sternoclavicular Joint

(Sternum & clavicle) Synovial joint w 3dg. of freedom

sternoclavicular joint actions

elevation/depression,

protraction/retraction,

rotation

Sternoclavicular ligaments

1. sternoclavicular (anterior/post)

2. costoclavicular

3. interclavicular

sternoclavicular ligament

connect clavicle to sternum on post & anterior

• anterior limits posterior vice versa

Costoclavicular ligament

Connects the clavicles inferior surface to the superior surface of the costal cartilage of the first rib

limits clavicular elevation

Interclavicular ligament

connects superior medial ends of the clavicle

limits clavicular depression

Acromioclavicular joint

Plane synovial jt with 3 dg of freedom

Acromioclavicular joint actions

scapular protraction/retraction

anterior/posterior tilting of scapula

upward/downward rotation of scap

Acromioclavicular joint ligaments

1. acromioclavicular ligaments

2. coraclavicular ligaments

3. coracoacromial ligaments

Acromioclavicular ligament

hold acromion and clavicle to each other

superior and inferior

Coraco-clavicular ligament

allow scapula to be suspended from the clavicle

lateral trapezoid, deeper medial conoid portion

Coracoacromial ligament

forms arch over head of humerus

(may be excised during “decompression” surgery)

Scapular movement

-elevation/depression

protraction/restraction

upward/downward rotation

scapular tilt

scapular winging

posterior lateral movement of the vertebral border of the scapula in the transverse plane.

scapular elevation/depression convex/concave Rule at SC

convex clavicle moves inferiorly and superiorly on the concave manubrium

Scapular protraction/retraction rule at SC

concave portion of the clavicle moves anteriorly and posteriorly on the convex costal cartilagerot

Rotation rule at SC joint

the clavicle spins on the sternum

Scapulohumeral Rhythm

describes the movement relationship between the shoulder girdle and the shoulder joint

(30 dg motion is GH, 2 dg of GH per 1 dg of scapular movement)

Muscles of shoulder girdle

Trapezius (Upper, middle, lower)

levator scapula

rhomboids

serratus anterior

pectoralis minor

Trapezius nerve innervation

Spinal Accessory (CN XI)

Upper trapezius origin

• Occipital protuberance,

• Spinous process of C1-C6 via nuchal ligament

Upper trapezius Insertion

• lateral third of clavicle

• acromion process

Upper trapezius action

• scapular elevation

• upward rotation

• retraction

Middle trapezius origin

• spinous process of C7-T3 via supraspinal ligament

Middle trapezius insertion

• medial aspect of acromion

• Spine of scapula

Middle trapezius action

• scapular retraction

• upward rotation

Lower trapezius origin

• spinous process of T4-T12 via supraspinal ligament

Lower trapezius insertion

• base of spine of scapula

Lower trapezius action

• scapular depression

• upward rotation

  • retraction

Levator Scapula origin

• transverse process of C1-C4

Levator Scapula insertion

-vertebral border of scapula between superior angle and spine of scapula

Levator Scapula nerve innervation

C3-C4 and dorsal scapular nerve

Levator scapula action

• Scapular elevation

• downward rotation

• lateral flex of cervical spine

Rhomboids origin

• spinous process of C7-T5 via nuchal and supraspinal ligaments

Rhomboids insertion

• vertebral border between base of spine of scapula and inferior angle

Rhomboids action

• Scapular elevation

• downward rotation

• scapular retraction

Rhomboids nerve innervation

• dorsal scapular nerve C5

Serratus anterior origin

• lateral surface of first thought 8th ribs

Serratus anterior insertion

• anterior portion of vertebral border of scapula

Serratus anterior action

• scapular protraction

• upward rotation

• Elevation of thoracic cage (inhale)

Serratus anterior nerve innervation

long thoracic nerve C5-C7

Pectoralis minor origin

• anterior surface 3rd-5th ribs

Pectoralis minor insertion

• coracoid process

Pectoralis minor action

• scapular protraction

• depression

• downward rotation

• elevation of thoracic cage (inhale)

Pectoralis minor nerve innervation

• medial pectoral nerve C8, T1

Force couples

two forces act in opposite directions causing rotation

Upward rotation force couple

upper trap pulls up + lower trap pulls down + serratus anterior pulls outward in an anterior direction

Downward rotation force couple

pectoralis minor pulls down + rhomboid muscle pulls in + levator scapula pulls up

PM of retraction

middle trap

rhomboids

PM of Protraction

serratus anterior

pectoralis minor

PM of Elevation

Upper trap

levator scapula

rhomboids

PM of Depression

Lower trapexius

PM of Upward rotation

Upper trap

Lower trap

serratus anterior

PM of Downward rotation

Pectoralis minor

rhomboids

levator scapula

PM of scapular tilt

pectoralis minor