Uppers Shoulder Flashcards
shoulder clinical anatomy
- static vs. dynamic stability
- common MOI
complex greatest ROM of any joint in the body static vs. dynamic stability -static: inert structures (labrum, ligaments, bony structures) -dynamic: muscles, nerves common MOI -direct force -indirect force --falling on an outstretched arm --overuse injury
shoulder joints
sternoclavicular joint
acromioclavicular joint
glenohumeral joint
scapulathoracic articulation
SC joint
- motions
- SC disc
only connection of upper extremity to axial skeleton gliding joint very little bony stability motions -elevation/depression -protraction/retraction -IR/ER SC disc -between distal end of clavicle and sternum -like the meniscus of the SC joint
SC joint ligaments
A/P SC ligaments -prevents A/P displacement interclavicular ligament -attaches clavicles -attaches to superior border of sternum costoclavicular ligament -attaches to first rib
AC joint
-motions
joint distal end of clavicle to acromion motions -IR/ER -upward/downward rotation -A/P scapular tipping
AC joint ligaments
acromioclavicular
coracoacromial
coracoclavicular
-conoid and trapezoid
GH joint
- type of joint
- motions
- combined movements
- angle of inclination
ball and socket joint -motion > stability motions -flexion and extension -abduction and adduction -internal and external rotation -horizontal abduction and adduction -circumduction over 16,000 combined movements angle of inclination -angle from shaft of humerus to head of humerus -130-150 degrees
GH joint
- glenoid labrum
- joint capsule
- ligaments
glenoid labrum
-cartilage ring that runs around the edge of the glenoid fossa
-deepends socket of shoulder
–provides stability
-long head of biceps tendon attaches on the glenoid at the labrum
joint capsule
-volume of the joint capsule is twice the volume of the humeral head
–not much stability
ligaments
-GH ligaments
–superior, middle, and inferior
–actually thickenings of the joint capsule
-coracohumeral ligament
GH joint
- coracoacromial arch
- plane of scapula
coracoacromial arch -formed by the coracoacromial ligament -protects the top of the humeral head -protects the rotator cuff tendons -protects the bursa plane of the scapula -the most functional plane of the rotator cuff is 30-45 degrees from the frontal plane
scapulothoracic articulation
- scapular movement
- scapulothoracic rhythm
“false joint”
moves in response to other joints
requires great dynamic stability
scapular movement
-superior/inferior (elevation/depression)
-anterior/posterior (forward/backward tipping)
-upward/downward rotation
-ER/IR
-medial/lateral movement (protraction/retraction)
scapulothoracic rhythm
-GH and scapulothoracic articulation must function together
–2:1 ratio GH:STA
bursae
subacromial bursa
-above supraspinatus tendon
-buffer between rotator cuff and acromion
subdeltoid bursa
muscles acting on the scapula
- functions
- muscles
functions -control position of glenoid -fix the scapula to give a stable base of support for the rotator cuff muscles -rhomboid major and minor -levator scapulae -serratus anterior -trapezius -latissimus dorsi -pectoralis major -pectoralis minor
rhomboids
downward rotation
retraction
elevation
levator scapulae
elevation
retraction
upward rotation (small)
serratus anterior
protraction
upward rotation
long thoracic nerve
trapezius
upper -upward rotation -elevation middle -retraction lower -upward rotation -retraction -depression
latissimus dorsi
depression (on scapula)
pectoralis major
depression (on scapula)
pectoralis minor
depression
muscles acting on the humerus
rotator cuff -subscapularis -supraspinatus -teres minor -infraspinatus deltoid pectoralis major latissimus dorsi
rotator cuff functions
subscap -IR - extension - horizontal adduction supraspinatus -abduction teres minor -ER - horizontal abduction infraspinatus -ER - horizontal abduction
force couples
two muscles that pull in two different directions to provide stability
best example
-deltoid/rotator cuff
–deltoid pulls up on humerus
–rotator cuff pulls down on humerus
–both function to keep the humeral head depressed within the glenoid
adhesive capsulitis
- MOI
- 4-step progression
- capsular pattern
- end-feel of shoulder
- Tx
- most common population
MOI -thickening (fibrosis) of the joint capsule 4-step progression -pain at deltoid insertion -night pain -pain at end range of motion (begin to see joint stiffness) -stiffness without pain capsular pattern -ER is the MOST limited -abduction is MODERATELY limited -IR is LESS limited end-feel of shoulder -IR/ER has hard/locking end feel Tx -will occasionally self-resolve, but not common -steriod injection -joint mobilizations occurs commonly post-op or after severe injury over the age of 50, white females
GIRD
-total arc of motion
common in overhead athletes, especially baseball
15-20 degree deficit when compared bilaterally
total arc of motion
-typically someone may make up for a deficit in one direction with extra mobility in the other direction
risk for other injuries
Tx
-stretching and mobilization