The Shoulder Complex Flashcards
What is the function of motion at the scapulothoracic joint ?
orient glenhoid fossa for optimal contact with the humeral head when mving arm and hand
SC Joint
elevation and depression
convex clavicle moves on concave sternum
SC elevation
superior roll inferior glide
What is the function of the SC disc in reference to SC stability?
disc increases stability by increasing joint congruence and abosrobes forces along clavicle
ER glenohumeral
posterior roll anterior glide
What is the function of rotator cuff during shoulder elevation ?
functions with deltoid to maintain congruence of the humeral head on the glenhoid
Upward rotators of scapula
upper trap, serratus anterior, lower trap
downward rotators of the scapular
Rhomboids and lats
What does the glenhoid labrum do?
enhances the depth of the glenhoid fossa
Scapula in resting position
between 2nd and seventh ribs
IR 35-45 deg from coronal plane
what supporting ligament of the GH joint is known as the ligament group?
inferior GH ligament
Inferior GH ligament
if shortened can result in excessive superior translation of humeral head and impinge during GH elevation
Superior GH ligament
taut when arm is fully adducted
Kinematics of GH abd
superior roll inferior glide
what muscle is the steerer of the GH joint?
supraspinatus
What is the resultant force of the rotator cuff?
slight ER followed by compressive force pulling humeral head into glenhoid fossa
Radial (lateral) collateral ligament
resists excessive varus forces
ulnar collateral ligament
resists excessive valgus forces
end feel of shoulder?
firm
spring block for rotation
capsular pattern of shoulder?
ER>abd>IR
What is the cellular unit of muscle ?
myofibril
open pack position of GH joint
55 abd , 30 horizontal adduction
normal anterior scapula tilt
10 to 15 deg and effects acromio clavicular joint
what does the word trochlea mean?
spool like
GH kinematics IR/ ER
IR anterior roll posterior glide
ER Poseterior roll anterior glide
