Shoulder Complex Biomechanics Flashcards
4 bones of shoulder complex
scapula, clavicle, humerus, sternum
four joints of shoulder
3 synovial (glenohumeral, acromioclavicular, sternoclavicular), 1 bone muscle bone articulation (scapulothoracic)
there are blank ligaments in shoulder complex
11
there are blank muscles in the shoulder complex
17
flexion, abduction, and scaption are all called blank because they have this ROM
elevation (170-180)
external rotation normal value in base position
40-60
external rotation normal value in supine abduction to 90 degrees position
90-100
internal rotation normal value in supine abduction to 90 degrees position
45-60
FIR will have thumb go to about blank
t5
FER will have thumb go to about blank
t3
horizontal abduction normal value standing
120-140
horizontal adduction normal value standing
40-60
plane of horizontal ab/adduction
transverse plane
extension or hyperextension normal ROM from standing
60-80
superior angle is usually at blank
t2
inferior angle is usually at blank
t7
about a blank distance between root of spine of scapula and t3
2 inch
3-5 degrees of upward scapular rotation is blank while downward is blank
good, bad
upward rotation promotes blank
inferior stability
a downwardly rotated scapula indicates adaptively blank sgh and coracohumeral ligaments
lengthened
scapular blank mechanism shows up as relaxation of sghl and chl and as a potential for false positive sulcus test
dumping
AMBRI stands for blank
atraumatic, multidirectional, bilateral, responds to Rehab, no Inferior capsular shift surgery needed
TUBS stands for blank
traumatic, unilateral lesion, Bankart lesion, requires surgery
disruption of anterior capsule of shoulder
Bankart lesion
scapular dumping typical posture is blank head and blank shoulders
protracted, rounded
slight anterior tilting or anteflexion of scapula by about blank degrees
9-20
excessive kyphosis will cause further blank of the scapula which sets up for a blank impingement
anterior tilting, external
pos means
plane of the scapula
pos is blank degrees anterior to frontal plane
30
scapulo clavicular angle is blank degrees
50
clavicular retraction angle is blank degrees
20
scapulothoracic motions do not occur blank
independently
elevation of scapula is a blank translation
cephalad
depression is a blank translation
caudal
protraction is coupled with blank rotation
medial
retraction is coupled with blank rotation
lateral
clavicle elevates and depresses the same as the blank
scapula
protraction is a blank translation
abduction
retraction is a blank translation
adduction
anterior tipping of scapula is coupled with blank and blank
upward rotation, protraction
posterior tipping of scapula is coupled with blank and blank
downward rotation, retraction
medial rotation of scapula has glenoid fossa going blank
anterior
lateral rotation of scapula has glenoid fossa going blank
posterior
rotary motions of scapula occur at the blank joint
ac
scapular winging results in blank displacement of the medial border of the scapula
posterior
pathological medial scapular rotation (winging) is due to either this muscle or blank nerve palsy
serratus anterior, long thoracic
upward rotation of scapula is coupled with clavicular blank
elevation
downward rotation of scapula is coupled with clavicular blank
depression
ac joint has a blank lateral clavicle and a blank acromion
convex, concave
ac joint is blank with a blank disc
synovial, fibrocartilaginous
ac joint is stabilized by these ligaments
conoid, trapezoid, ac
ac joint is configurated blank
incongruent
sc joint is blank with a blank disc
synovial, articular
sc joint is blank clavicle on blank sternum in the frontal plane
convex, concave
sc joint is blank clavicle on blank sternum in the transverse plane
concave, convex
sc joint is a blank joint
saddle synovial
ligament that limits clavicle elevation at sc joint
costoclavicular ligament
transverse plane motions of sc joint
posterior/anterior roll/glide
frontal plane motions of sc joint
superior/inferior roll/glide
sc joint has no anterior rotation from blank
anatomic neutral
there is a max of blank humeral head in contact with glenoid
1/3
ap cross section shows a smaller blank than si cross section
concavity
humeral head faces blank, blank, and blank
medially, superiorly, posteriorly
full normal er and ir are from purely blank joint
gh
full elevation of upper extremity requires blank to prevent impingement of greater tuberosity of humerus against acromion and provide greater humeral head blank
er, articular surface
gh joint is blank on blank
convex, concave
integrated fxn of sc, ac, gh, and scapulothoracic joint is called blank
scapulohumeral rhythm
scapulohumeral rhythm allows for the maintain optimum blank relationship for scapulohmeral musculature
length tension
phase 1a of ue elevation is mostly blank
gh
there is an blank pattern of scapular motion during phase 1a
inconsistent
scapula is simply blank during phase 1A
stabilizing
phase 1A is during blank degrees of scaption and blank degrees of flexion
0-30, 0-60
phase 1B is during blank degrees of scaption and blank degrees of flexion
30-90, 60-90
consistent blank of scapula during phase 1B of ue elevation
upward rotation
acromion ellevates as well as blank during 1B
clavicle
phase 2A is during blank degrees of elevation
90-120
clavicular elevation blank loads cc ligaments during 2A
tension
as clavicle elevation slows during 2A, instantaneous center shifts to blank joint
ac
phase 2B is during blank degrees of elevation
120 - end ROM
IC of rotation is at blank during 2B
ac joint
scapular upward rotation is accompanied by corocoid blank during 2B
depression
depression of corocoid tension loads blank ligaments
cc
cc tension load imparts a blank force on the posterior clavicle via the blank ligament
downward, conoid
blank clavicular rotation occurs during phase 2B
posterior
clavicles shape
crank
clavicle shape allows blank degrees of elevation of outer clavicle
30
posterior clavicle rotation aids scapular blank tilting/tipping
posterior
during this phase, trapezius can finally produce upward scapular rotation
2b
the gh joint does not blank
elevate
the deltoid tries to pull the humeral head blank
superior
deltoid and rc are a blank pair to bring arm overhead
syngergistic
most important synergist with deltoid to raise arm overhead
supraspinatus
greater compressive force reduces blank force
shear
subscap, infraspinatus, and teres minor all help the supraspinatus because they have a blank directed force
medially
in coracoacromial space there is only blank space
4 dimes high
impingement is a blank
etiology
superior impingement is due to a weak blank and blank taking over
rotator cuff, deltoid
bone spur on acromion can tear the blank muscle
supraspinatus
torn supraspinatus and teres minor are likely to have a torn blank because of negative pressure
capsule
sticking a needle into subacromial space with produce immediate blank because of venting
inferior subluxation
shoulder will often pop and crack a couple days after cortisone shot because of blank
negative pressure
this envelopes the humeral head
labrum
labrum is blank thick inferior and superior but blank thick anterior and posterior
more, less
intact labrum, the gh joint resists dislocation forces of up to blank percent of compressive loads in the inferior direction
64
removed labrum there is a blank percent reduction in dislocation protection
20%
deltoid, supraspinatus, infraspinatus, teres minor all blank humeral head into cavity
compress
strengthening rotator cuff is like a buttressing effect because it aids in blank of the humeral head in the glenoid
centering
part of capsule that restrains flexion
posterior capsule
gh ligaments are only check reins when the motion is near blank
end range
tight anterior capsule would cause a blank translation
obligate posterior
tight posterior capsule would cause a blank translation
obligate anterior
overly aggressive stretch can cause hypermobility and a blank
internal impingement (tendonitis)
three parts of inferior glenohumeral ligament
anterior band, axillary pouch, posterior band
flexion check reins
middle posterior capsule, anterior coracohumeral ligament
abduction check reins
posterior coracohumeral ligament, inferior posterior capsule
internal rotation check reins
superior/middle posterior capsule, middle glenohumeral ligament
check reins for external rotation
superior/middle glenohumeral ligament, anterior/posterio coracohumeral ligament
sghL is also a primary stabilizer to blank humeral head translation
anterior
not much ligamentous restraint for blank translation of humeral head
posterior
for 45 degree scaption, blank resists anterior humeral head translation mostly
MGHL
90 degrees scaption, blank stabilizes against anterior humeral head translation
IGHL
IGHL during internal rotation goes blank
superior
IGHL during external rotation goes blank
inferior
hypermobility on one side of capsule can lead to tear on blank
opposite side (circle of instability)
