Kinesiology of the Shoulder Flashcards
What are the bones involved in the bony aspect of the shoulder girdle?
manubrium
clavicle
scapula
humerus
ribs
The clavicle and scapula make up the shoulder girdle proper
What are the 4 joints of the shoulder girdle?
sternoclavicular
acromioclavicular
glenohumeral
scapulothoracic
What is the closed pack position of the SC joint?
full elevation
What is the capsular pattern of the SC joint?
Pain at extreme ranges, especially horizontal add. and full elevation
What is the typical dislocation of the SC joint?
clavicle moves anterior medial
What joint serves as the only bony connection for the entire shoulder girdle?
the SC joint
What type of joint is the SC joint?
multi-axial saddle synovial joint
What does the SC joint connect?
the clavicle, and the junction of the manubrium and 1st costocartilage
What does the disc in the SC joint do?
increases joint congruence and acts as a shock absorber
What are the 3 major ligaments of the SC joint?
interclavicular
posterior and anterior sternolavicular
costoclavicular
What does the interclavicular ligament limit?
inferior clavicular movement
What does the posterior and anterior sternoclavicular ligament limit?
posterior and anterior clavicular movement
What does the costoclavicular ligament limit?
elevation and protraction-retraction
serves as the axis for protraction retraction and elevation-depression
What is the ratio of the scapulohumeral rhythm?
generally 1:2 (for every degree of scapular motion the humerus moves 2 degrees)
What movements do the scapulohumeral rhythm refer to?
Primarily abduction, but also flexion and scaption
What happens in the first 30 degrees of abduction?
movement occurs primarily in the GH joint with the scapula moving only to find a stable position or setting
What happens from 30 to 90 degrees of abduction?
The scapula moves about an axis of rotation located at the base of the spine of the scapula
superior scapular rot. and clav. elev. result from the action of upper & lower trap as well as serratus ant.
scapula rotates 30 degrees and humerus has abducted 60 degrees
What happens from 90 to 165 degrees of abduction?
glenoid rotates sup. putting tension in the c.clav. lig. that the post. clavicle is drawn ant. inferior.
results in post. rotation (30-50 deg) about the long. axis of the clavicle which flips the lat. end superiorly (S shape)
AC JT elevated and scapula is rotated a further 30 deg.
at this point the scapula has rotated sup. 55 deg and the humerus abd. 110 degrees
What happens from 165 to 180 degrees of abduction?
unilateral arm = contralateral lateral flexion of spine
BL arm = extension (lumbar lordosis)
What can cause restrictions in abduction?
reverse scapulohumeral rhythm
fused SC JT
no external humeral rotation
no clavicular rotation
What are the prime movers of the shoulder girdle?
deltoid
supraspinatus
trapezius
latissimus dorsi
pec major
levator scapulae
What are the synergists of the shoulder girdle?
infraspinatus
teres minor
subscapularis
rhomboid major and minor
subclavius
long head biceps brachii
traps and serratus anterior
lats and pecs
supraspinatus
What are the movements of the SC joint?
protraction-retraction
elevation-depression
rotation
What are the axis and plane of protraction-retraction of the SC joint?
vertical axis
transverse plane
