Exam 3 Flashcards
1
Q
what is the sternoclavicular jt
A
clavicle like a strut holding the scapula
2
Q
what is the acromioclavicular jt
A
firmly attaches the scapula to clavicle
3
Q
what is the scapulothoraic jt
A
not a true jt
interface between bones
link to SC and AC
base of GH jt
4
Q
what is the glenohumeral jt
A
most distal and mobile portion of the whole complex
5
Q
what can happen to the shoulder complex when weakened or painful
A
decreases effectiveness of the entire UE
6
Q
what are the slides of elevation and depression
A
ele- sup slide
dep- inf slide
7
Q
where does the medial border of scapula slide in protraction and retraction
A
pro- ant and lat
re- post and med
8
Q
describe the SC jt
A
basilar jt of UE
large ROM
irregular saddle shape
convex and concave with sternal facet reciprocally shaped
9
Q
what is the longitudinal diameters in the SC jt
A
frontal plane
sup and inf points
10
Q
what is the transverse diameters of SC jt
A
horizontal plane
ant and post points
11
Q
what muscle can restrict the clavicle movement
A
subclavius
12
Q
what muscles can affect the movement of SC jt
A
SCM
sternothyroid
sternohyoid
subclavius
13
Q
where does the costoclavicular lig attach to
A
clavicle to 1st rib
14
Q
what movements does the clavicle do
A
3 DOF- all 3 with UE elevation
ele/dep
protract/retract
rotates
15
Q
what is the goal of SC
A
to place scapula in optimal position for head of humerus
16
Q
what is the osteo of the SC joint
A
axis= AP
35-45 elevation
10 depression
clavicular promotes scapula motions
17
Q
what is the arthro for SC elevation
A
convex surface rolls sup and slides inf
CCL ligament stretches
18
Q
what is the arthro for SC depression
A
convex surface rolls inf and slides sup
ICL lig stretches
19
Q
what is the osteo of SC protraction
A
axis- vertical
15-30 degrees
associated with scapula pro/re
20
Q
what is the arthro of SC retraction
A
concave surface of clavicle rolls and slides post
stretches ant CCL and ant capsule
21
Q
what is the arthro of SC protraction
A
concave surface of clavicle rolls and slides ant
stretches post CCL and post capsule
22
Q
what is the osteo of SC rotation
A
longitudinal axis
20-35 degrees
23
Q
what is the arthro of rotation of SC
A
spin of sternal end relative to lateral surface
linked with flx and abd
24
Q
what is the coracoclavicular lig
A
extrinsic stability for AC
trapezoid and concoid
coracoid process to clavicle
25
what are the kinematics of AC jt
3 DOF
up/down rotation
secondary motion= rotational adjustment
26
describe upward rotation of scapula at AC
swings up and out
up to 30 degrees
contributes to scapulothoracic motion
27
describe the downward rotation of scapula at AC
return to anatomical position
28
describe the rotation of AC in horizontal plane
vertical axis
medial border moves away (IR)
29
describe the rotation of AC in sagittal plane
Tilting
ML axis
inferior angle moves away- ant or post tilting
30
describe the protraction of AC jt
internally rotates in horizontal plane
align ant surface of scapula and thorax
31
what happens to the scapula with IR
ant tilting
upward rotation
32
where does the scapula sit
between 2-7 ribs
medial border 6 cm lateral to spine
33
what are the ranges for the scapulathoracic jt
ant tilt- 10 degrees
upward rotation- 5-10
IR- 30-40
34
how is the motion for protraction/retraction of scapulothoracic jt
SC pro/re plus AC IR/ER
35
how is the motion of upward/downward rotation of scapulothoracic jt
SC elevation plus AC upward rotation
60 degrees upward rotation
36
how is the humeral head postioned
medial, superior, posterior
37
how is the glenoid fossa positioned
anterior-lateral in scapula
38
what is the axillary pouch
anatomic postion inferior portion of capsule is slackened
39
what lines the humeral head and glenoid fossa
articular cartilage
40
what is the potential size of the GH jt
2x humeral head
41
describe the fibrous capsule of GH jt
rim of glenoid fossa to anatomic neck
loose fitting
allows mobility and reinforced by ligaments
42
what allows for GH jt stability
passive tension of lig
active forces- RTC
long head of biceps crosses sup over head
43
describe GH superior capsular lig
resists ER and ant/inf translation
44
describe the GH middle capsular lig
stabilizes most motion
ant restraint of 45-90 abd and ER
45
describe the GH inf capsular lig
3 bands
taut in 90 abd
resists inf/ant-post translations
46
what is the coracohumeral lig
blends with sup capsule
taut in anatomical position
restrain inf translation and ER
47
what is the RTC interval
common site of dislocation
reinforced by LHB, coracohumeral lig and sup/mid capsule
48
describe the LHB
supraglenoid fossa and labrum
intratubercle groove on ant humerus
resists ant translation
ABD
49
describe the labrum
fibrocartilage
stabilzer
50
describe the coracoacromial arch and bursa
arch= coracoacromial lig and acromion process
roof of GH jt
1 cm in adults
51
what is contained in the coracoacromial arch and bursa
supraspinatus
subacromial bursa
LHB
sup capsule
52
where is the subacromial space
between arch and humeral head
53
what is the subacromial bursa
protects SS from acromial bone
54
what is the subdeltoid bursa
limites friction between deltoid and SS tendon and humeral head
55
describe the ABD and ADD of humerus
frontal A-P
120 degrees, also with 60 deg scap RT
convex rolls sup and slides inf on concave
opposite in ADD
56
what is dynamic stability
supraspinatus tendon blends with superior capsule
contraction pulls capsule tight=no pinching
57
what is adhesive capsulitis
excessive thickening or stiffness in ICL
limits inferior slide of humeral head (sup roll)
58
what is impingement syndrome
unnatural and repeated compression/abrasion damaging the SS tendon, subacromial bursa, LHB tendon or sup capsule
59
describe FLX of humerus
sagittal M-L
120 deg/180 with scap
most structures are taut
tension in post capsule= ant translation
60
describe EXT of humerus
65 deg active/ 80 passive
slight ant tilt of scap= stretch capsular lig
61
describe IR of humerus
horizontal plane SI
75-85 deg
rolls ant slides post
62
describe ER of humerus
horizontal SI
60-70 deg(can be up to 90)
rolls post and slides ant
at 90 deg ER is all spinning
63
what is scapulohumeral rhythm
natural rhythm between GH ABD and ST upward RT
after 30 degrees ABD= rhythm consistent
2 deg GH + 1 deg ST = 3 deg
full arc = 120 GH/60 ST
64
what is the result of 60 deg of scapula with ABD at SC and AC jt
SC= elevation (30 deg)
AC= upward RT
65
what does the clavicle do at the SC jt during full ABD
retract (15-20 deg)
66
how is the scapula positioned at full ABD
tilts posteriorly (20 deg) and rotates outward
67
how does the post tilt and ER of scapula in ABD help
keeps scapula flush with thorax
orients fossa
68
how is the scapula normal positioned
ant tilt (10 deg)
IR (30-40 deg)
69
what does the clavicle do during ABD
posteriorly RT along axis
20-35 deg
most predominant motion
70
what happens to the clavicle during ABD if there is an subacromial impingement
reduced RT
71
what happens to the humerus during ABD (beside the Arthro)
ER
allows to pass post acromion
25-50 deg before 70-80 deg of ABD
72
what is the sensory innervation of the SC jt
C3-4
73
what is the sensory innervation of the AC and GH jt
C5-6
suprascapular and axillary n
74
what nerves come from the posterior cord
upper subscapular n
thoracodorsal n
lower subscapular n
axillary n
75
what n come from the proximal segments of the brachial plexus
dorsal scapular
long thoracic
pectoral
suprascapular
76
what are proximal stabilizers
originate from spine/ribs/cranium and insert on the scapula and clavicle
77
what are distal mobilizers
originate on scapula and clavicle and insert on humerus or forearm
78
what muscles elevate the ST
UT (CN 11)
levator scapulae (dorsal scapular)
rhomboids (dorsal scapular)
79
what muscles retract ST
MT (cn 11)
rhomboids (dorsal scapular)
LT (cn 11)
80
what muscles depress ST
LT (cn 11)
Lat dorsi (thoracodorsal)
Pec minor (medial pectoral)
subclavius (subclavian)
81
what muscles protract ST
SA (long thoracic)
pec minor (medial pectoral)
82
what muscles upward rotate ST
SA (long thoracic)
U/MT (cn 11)
83
what muscles downward rotate ST
rhomboids (dorsal scapular)
pec minor (medial pectoral)
84
what is the function of the elevators
support the posture of the sh girdle
85
what can happen if elevator m support is lost
can damage underlying structures
86
how is the Lat dorsi a depressor
pulls humerus inf leading to indirect depression
87
what can the pec minor limit if tight
retraction
88
what are the retractors main function
proximal stabilizers anchoring scapula to axial skeleton
essential for pulling activities
89
what 3 groups of m help elevate the arm and their function
muscles that elevate the humerus at GH
scapular m that control up RT of ST
RTC m that control dynamic stability and arthro of GH
90
what muscles elevate the humerus
ant/mid deltoid (axillary)
supraspinatus (supraclavicular)
coracobrachialis (musculocutaneous)
biceps brachii (musculocutaneous)
91
when are the m that elevate the humerus activated with ABD
between 60-90 deg
ant/mid deltoid and SS share equally
92
what are the roles of the upward RT of ST
drive up RT and RT adjustments
provide stable attachments for distal mobilizers (deltoid and RTC)
93
what can happen if you have paralysis of the trap
with full ABD (very difficult) = T spine extends 10-15 deg
control of scapula changes
excessive protraction
94
what can happen if you have paralysis of the SA
downward RT position
abnormal ant tilt and IR
can not resist the deltoid and SS pull in ABD
95
what is scapular dyskinesis
abnormal position or movement of the scapula
reduced up RT
excessive down RT, IR, ant tilt/elevation
96
what are type 1 and 2 prominences of the inf and med border of the scapula indicating
labrial lesions
97
what does type 3 prominence of superomedial border of scapula indicating
impingement and RTC lesions
98
what is function of RTC m during elevation of arm
regulators of dynamic jt stability and control jt arthro
compensates for natural laxity
RT, compress, and stabilize in fossa
99
what m FLX the humerus
ant deltoid (axillary)
coracobrachialis (musculocutaneous)
biceps brachii (musculocutaneous)
100
what m ABD the humerus
mid deltoid (axillary)
supraspinatus (suprascapular)
101
where does the RTC distally attach
blends into capsule before attaching to humerus
102
what is the action of the SS when ABD of GH
rolls humeral head sup while compressing for stability
103
what is the action of the IS, SubS, and TMin when ABD of GH
downward translation on humeral head due to SS sup translation
104
what other action is IS and Tmin doing during ABD of GH
ER humerus to create clearance
105
what m ADD and EXT the sh
post delt (axillary)
lat dorsi (thoracodorsal)
LH triceps (radial)
pec major (med and lat pectoral)
IS (supraclavicular)
Tmin (axillary)
106
what is required for the sh to ADD/EXT
scapula stabilization with rhomboids
107
what m IR the sh
subscapularis (lower subscapular)
pec major (med and lat pectoral)
lat dorsi (thoracodorsal)
teres major (lower and upper subscapular)
ant deltoid (axillary)
108
what m ER the sh
infraspinatus (suprascapular)
Tmin (axillary)
post deltoid (axillary)
109
what m has the greatest moment arm of IR and which has the least
subscapularis
ant deltoid
110
which movement (IR or ER) has the greatest mass and torque
IR by 40-70% of torque
111
in throwing sports what movement (IR or ER) has the most internal torque and which has the strongest deceleration force
IR largest torque
ER largest deceleration
112
what muscle contraction has peak force
eccentric forces
