Shoulder Flashcards
0
Q
What is the function of the shoulder joints
A
Link the upper extremity to the trunk
Provide extensive movement of the arm in space.
Provide stability for the elbow and hand for skills of forceful movements
1
Q
Anatomical and functional structures and function of the shoulder joints
A
Anatomical:
Sterno-clavicular
Acromioclavicular
Glenohumeral
Functional–scapulothoracic and coracromial arch
2
Q
Structural stability of the joint complex depends on?
A
Shape of the articulation
Bony incongruity
3
Q
Muscles, ligaments, and soft tissues maintain what
A
Joint integrity
4
Q
Joint stability is due to what
A
Dynamic muscular control
5
Q
_____ is a segment that depends on more muscles and ligaments than on bony configuration for structural integrity
A
Dynamic stability
6
Q
____ normal position of the scapula in relation to the trunk in all three planes.
A
Alignment
7
Q
What connects the cervical and thoracic spine to the scapula
A
Muscles
8
Q
What are the positional relationships regarding the planes of the scapula
A
Due to the spherical shape of the trunk:
Transverse plane the scapula is rotated anteriorly
Frontal plane the scapula is rotated anteriorly
9
Q
The plane of the scapula is oriented approximately ____ to the frontal plane
A
30-45 degrees
10
Q
The glenoid fossa is directed ____ with respect to the body
A
Anteriorly
11
Q
Movement in the plane of the scapula in a range between 30-45 degrees anterior to the frontal plane.
A
Elevation or scaption
12
Q
Joint capsules in elevation or caption are in what position
A
Loose-packed position
13
Q
Is there impingement of the supra humeral joint if shoulder motions occur in the plane of the scapula in regards to scaption
A
No
14
Q
What is the function of the glenoid fossa being rotated anteriorly
A
Alignment: less stress on the capsule and musculature
Strength: optimal length-tension relationship for shoulder abductors and rotators. Supraspinatus and deltoid are optimally aligned for elevation.
15
Q
How much movement is involved in elevation at the humerus
A
Little or no rotation of the humerus in elevation
16
Q
What is the position of the scapula relative to the spine
A
Superior angle is at T2 spinous process
Inferior angle is at T7 spinous process
5-6 cm between the spine and the medial scapular border (at T4)
Alterations from the ideal alignment may indicate functional impairments
17
Q
Ideal alignment from the side view
A
Acromion- in line with the mastoid process. 20 degree anterior tilt between the lateral border of the scapular border and vertical.
Alterations from the ideal alignment may indicate functional impairments.
18
Q
What is the angle of inclination
A
In the frontal plane
130-150 degree angle is created between the axis of the head and the shaft of the humerus.
19
Q
What is the angle of torsion–> retroversion
A
Transverse plane: the humeral head is rotated 30 degrees posteriorly relative to the epicondyles. It orients the humeral head in the scapular plane for articulation with the glenoid fossa. It increases stability
20
Q
What are the functions of the clavicle
A
Strut to hold shoulder onto axial skeleton
Site for muscular attachment
Protect underlying nerves and blood vessels
Contributes to increased range of motion of the shoulders
Transmit muscle forces to the scapula
21
Q
Describe the arthrology of the sternoclavicular joint
A
Bony connection of the upper limb to the axial skeleton. It’s triaxial and a saddle joint. There are three degrees of freedom and some people argue its a ball in socket joint. It is reciprocally convex/concave
22
Q
Stability of the sc joint depends on ____ and _____
A
Capsule and ligaments
23
Q
What is the periarticular connective tissue of the sc joint
A
Joint capsule Intraarticular disc Sternoclavicular (capsular) ligament (A and P) Interclavicular ligament Costoclavicular ligament
24
____ principle stabilizing structure of the sterno-clavicular joint. It secures the clavicle to the first rib and limits extremes of all clavicular motion except depression.
Costoclavicular ligament
25
What are the axis of the Costoclavicular ligament
Protraction/retraction
| Elevation/depression
26
______ lines the superior aspect of the joint capsule. It checks anterior and posterior movement.
Anterior and posterior sternoclavicular ligament
27
What does the anterior and posterior sternoclavicular ligaments restrain
Posterior--protraction
| Anterior--retraction
28
What does the articular disc do in the sc joint
It is Fibrocartilage and absorbs shock and helps prevent dislocation
29
The articular surface of the ____ is greater than the _____ which results in joint instability
Clavicle
| Sternum
30
_____ increases the articular surface between the clavicle and sternum
Intra-articular disc
31
_____ helps block medial movement of the clavicle and helps distributes forces
Intra-articular disc
32
The force to the lateral shoulder pushes the clavicle _____
Medially
33
Osteokinematic motion is always names for the direction of the movement ______
At the end of the lever
34
What are the osteokinematics of the sc joint
```
Plane synovial joint but sometimes considered a saddle
3 degrees of freedom
Elevation/depression
Protraction/retraction
Rotation
```
35
Osteokinematics at the sc joint of elevation and depression
Frontal plane
A-P axis at the Costoclavicular ligament
Elevation 45 degrees
Depression 5-15 degrees
36
Osteokinematics of protraction/retraction at the sc joint
Transverse plane
Vertical axis at the Costoclavicular ligament
Protraction 15-30 degrees
Retraction 15-30 degrees
37
Osteokinematics of rotation at the sc joint
Longitudinal axis through the clavicle
| 30-40 degrees of spin
38
Arthrokinematics of the sc joint
Elevation and depression occur along the longitudinal diameter
Protraction and retraction occur along the transverse diameter
39
Explain the arthrokinematics of elevation at the sc joint
Convex clavicular surface rolls superiorly and slides inferiorly on the concavity of the sternum.
40
Explain depression for arthrokinematics of the sc joint
Convex clavicular surface rolls inferiorly and slides superiorly
41
Arthrokinematics of retraction at sc joint
Concave articular surface of the clavicle rolls and slides posteriorly on the convex surface of the sternum
42
Arthrokinematics of protraction of the sc joint
Concave articular surface of the clavicle rolls and slides angrily on the convex surface of the sternum
43
Arthrokinematics of rotation at the sc joint
Spin of the head of the clavicle about the disc
44
The closed pack position at the sc joint is ____
Posterior rotation
45
_____ is a gliding or plane synovial joint with 3 degrees of freedom.
Acromioclavicular joint
46
At the ac joint describe the proximal and distal components
Proximal--convex lateral end of the clavicle
| Distal--concave acromion process of the scapula
47
What is the periarticular connective tissue at the ac joint
Superior and inferior ac ligaments
Coracoclavicular ligament
Conoid and trapezoid
Articular disc
48
_____ reinforces the joint capsule, prevents post dislocation! and limits tipping
Superior and inferior AC ligaments
49
____ binds the clavicle to the scapula--major stabilizing structure
Coracoclavicular ligament
50
____ limits excessive superior glide
Conoid
51
____ protects against shearing forces
Trapezoid
52
What are the primary and secondary motions at the ac joint
Primary-- upward and downward rotation
Secondary--horizontal plane adjustments--internal and external rotation
Sagittal plane adjustments--anterior and posterior tilting
53
Osteokinematics of upward and downward rotation in the scapular plane
Primary motion at the ac joint
Glenoid fossa tilts up or down
Closed packed position and fully upward rotation
A-P axis: 1st 30 degrees--axis at base of spine of scapula
Last 30 degrees--axis at the ac joint
54
Osteokinematics of external/internal rotation
Horizontal plane adjustment
| Vertebral border of the scapula moves out around a vertical axis at the ac joint.
55
Scapular internal/external rotation occurs with what?
With scapular abduction/adduction
56
What would happen if abduction and adduction were pure translatory movement
Only the vertebral border of the scapula would contact the ribs
57
Osteokinematics of anterior and posterior tilting at the scapula
Sagittal plane adjustment
| Titling of the scapula--horizontal axis
58
Anterior and posterior tilting of the scapula occurs with what movement
Scapular elevation and depression
59
Describe the movement of anterior tilting
Inferior angle moves away from the thoracic wall
60
What joint of the shoulder is not a true anatomical joint
Scapulothoracic joint
61
How does the st joint function as a joint
The proximal component--convex rib cage
| Distal component--concave anterior scapular surface
62
What is the function of the st joint
Orientation of the glenoid fossa
63
What does scapular motion serve to do at the st joint
It serves to move the glenoid fossa into a position where it can provide a stable base for the humeral head regardless of arm movement.
64
Where does the st joint lie
In the scapular plane not the frontal plane
65
Sc, ac, and st joints are
Closed kinematic chain
66
St joint movements require simultaneous movements at the _______ joints
Sc and ac
67
Osteokinematics of the st joint
Elevation/depression
Abduction/adduction
Upward/downward rotation
68
Osteokinematics of elevation and depression at the st joint
Elevation--entire scapula moves superiorly
Depression--entire scapula moves inferiorly
Composite of sc and ac rotations--sc is elevation and depression and ac is tipping/tilting
69
Osteokinematics of the st joint with adduction/abduction (protraction/retraction)
Side to side translation of the scapula on the ribs (parallel). It's moving towards or away from the spine.
70
What movements are happening at the ac and sc joints with st joint adduction/abduction
Sc--protraction/retraction
| Ac--internal/ external rotation
71
Describe protraction and retraction at the st joint
Protraction--upward forward reach
| Retraction-- pulling toward the body
72
Osteokinematics of the st joint for upward rotation
Glenoid fossa faces superiorly, inferior angle slides laterally and anteriorly.
73
Upward rotation at the st joint occurs with?
It occurs with flexion, abduction, or elevation of the arm (raise arm overhead)
74
What movements are happening at the sc and ac joints with upward rotation at the st joint
Sc--clavicular elevation
| Ac--scapular upward rotation
75
Osteokinematics of the st joint for downward rotation
Glenoid fossa faces inferiorly, the inferior angle slides medially and posteriorly upward. The inferior angle moves away from the vertebra.
76
What motions are occurring at the ac and sc joints for st joint downward rotation
Sc--clavicular depression
| Ac--scapular downward rotation
77
Example of st joint downward rotation
Reaching under your desk
78
Arthrology of the GH joint
There is little bony congruity
There is passive tension on the periarticular connective tissue
There is active muscle tension
79
At the GH joint ____ and _____ are exchanged for _______
Congruency and stability
Mobility
80
What is the periarticular connective tissue in the GH joint
Capuloligamentous complex--capsule and axillary pouch
Glenoid labrum
Glenohumeral and Coracohuneral ligaments
Coracoacromial arch
81
_____ is the rim of the glenoid fossa-->anatomical neck of the humerus and allows for extensive mobility
Capsule of the capsuloligamentous complex
82
_____ is Fibrocartilage surrounding the fossa and deepens the fossa. It increases the articular contact, improves osseous stability, improves articular congruity.
Glenoid labrum
83
The glenoid labrum increases the fossa's depth by ___
50%
84
The _____ decreases the humeral head translation
Glenoid labrum
85
_____ reinforce the capsule and serve as the major static restraints
Glenohumeral and Coracohuneral ligaments
86
The ______ is the anterior capsular reinforcement for the GH joint
Subscapularis
87
______ are the posterior reinforcement of the GH joint
Supraspinatus
Infraspinatus
Teres minor
88
The glenohumeral ligament provides _____ thickening of the joint capsule
Anterior
89
The glenohumeral ligament is ____ in normal rom
Lax
90
______ limits translation and rotation of humeral head on the glenoid. It prevents extremes of range and is useful in joint stabilization
Glenohumeral ligament
91
____ is attached at the supra glenoid tubercle and the lesser tuberosity
Superior glenohumeral ligament
92
_____ is taut with full adduction, inferior and anterior and posterior translation
SGHL
93
Where does the mghl attach
Labrum and anatomical neck
94
______ anterior restraint to the GH joint, resists anterior translation of the humerus. 45-60 decrees abduction and external rotation
MGHL
95
Where does the IGHL attach
Anterior inferior and glenoid labrum
| Inferior anatomical neck of the humerus
96
Where are all fibers taut for the IGHL
90'degrees abduction
97
Where does the Coracohuneral ligament attach
Lateral coracoid process
| Anterior greater tubercle
98
What is the strongest supporting GH ligament
Coracohumeral ligament
99
Where is the Coracohuneral ligament taut
At extremes of external rotation, flexion, and extension
100
What is the primary restraint in the inferior and posterior translation in the adducted arm
Coracohuneral ligament
101
_____ counteracts the downward pull on gravity on the humerus
Coracohumeral ligament
102
GH static stability primary
Fossa oriented upward
| Combine force of coracohumeral ligament, superior capsule and force of gravity
103
GH static stability secondary
Supraspinatus and posterior deltoid--active forces parallel to superior capsule.
Decreases superior capsule equals muscle weakness and poor posture
104
What makes up the coracromial arch
Coracromial ligament and acromion process
GH roof--protective
Subacromial space---supraspinatus, Subacromial bursa, biceps-long head, capsule
105
Closed packed position of GH joint
Full abduction with external rotation
| Max congruency between the glenoid fossa and humeral head
106
Osteokinematics of GH joint abduction
Frontal plane rotation
A-P axis at the center of the humeral head
120 degrees abdcuction at GH joint
107
Arthrokinematics of the GH joint for abduction
Convex humeral head rolls superiorly and glides inferiorly
108
Kinematics of abduction of the GH joint
Humeral head is greater than the glenoid fossa
| Rolling without inferior sliding of the humeral head--> impingement of supraspinatus tendon and Subacromial bursa.
109
Osteokinematics of the GH joint for flexion and extension
Sagittal land rotation.
Med-lateral axis
Flexion. At 120
Extension. 40-55
110
Arthrokinematics of the GH joint for flexion and extension
Flexion--posterior spinning of the humeral head
111
Osteokinematics of the GH joint for internal and external rotation
Axial rotation of the humerus in the horizontal plane
| Vertical or longitudinal axis
112
Rom in neutral abdcuction. For GH joint
Er-- 60-70
| Ir-- 75-80
113
Rom in 90 degrees abduction
Er 90
| Ir75-90
114
Arthrokinematics of external rotation at the GH joint
Humeral head rolls posteriorly and slides anteriorly
115
Arthrokinematics of internal rotation at the GH joint
Humeral head rolls anteriorly and slides posteriorly
116
_____ is the simultaneous kinematic movement of all shoulder joints
Scapulohumeral rhythm
117
_____ is a coordinated series of synchronous movements which distributes motion between the GH and ST joints {sc and ac}
Scapulohumeral rhythm
118
What is the function of the Scapulohumeral rhythm
Permits larger ROM with less compromise to stability.
Maintains the humeral head in an optimal position in the glenoid fossa.
Muscles acting on the humerus maintain a good length-tension relationship.
119
How many principles of the Scapulohumeral rhythm are there
6
120
What is principle 1
2:1 Scapulohumeral rhythm. Active abduction of 180 degrees occurs as a result of simultaneous 120 degrees of glenohumeral abduction and 60 degrees of scapulothoracic upward rotation.
For every 2 degrees of GH movement there is 1 degree of scapular rotation. Ratio is 2:1
121
What is principle 2
60 degrees of scapulothoracic upward rotation --> simultaneous motion at the sc and ac joints
Sc elevation
Ac upward rotation
122
What is principle 3
The clavicle retracts at the sc during full abduction.
Clavicular retraction assists ac to position the scapula optimally.
123
What is principle 4
The scapula posteriorly tilts (at AC) and externally rotates during full shoulder abduction.
External rotation occurs as a net rotation based on sc and ac movements.
124
What is the function of Scapulohumeral rhythm principle 4
Moves the coracoacromial arch away from the advancing humeral head
Limits likelihood of impingement
Decreases the mechanical stress on the capsule and the rotator cuff.
125
What is principle 5
Posterior rotation of the clavicle. The Coracoclavicular ligament attaches the scapula to the clavicle. As the serratus anterior and lower trap upwardly rotate the scapula, the Coracoclavicular ligament gets taut.
126
In principle ______ the clavicular elevation pulls on the Coracoclavicular ligament and the S-shaped clavicle rotates posteriorly around its longitudinal axis.
5
127
Principle 5 allows for the last _____ of ______
30 degrees
Upward rotation
128
In principle ______ the GH externally rotates during shoulder abduction. External rotation allows the greater tubercle to pass posterior to the acromion and avoids impingement of Subacromial space contents.
6
129
A muscle's ability to produce movement in a plane is dependent on?
Location of the muscle action line
Axis of rotation
130
Attached to axioskeleton and shoulder girdle
Axioscapular and axioclavicular
131
Attach scapula to humerus (includes rotator cuff)
Scapulohumeral
132
Attach thorax to humerus
Axiohumeral
133
_____ a weak agonist, a tight agonist, or a combination of the two
Muscle imbalance
134
_____ shorten and tighten in dysfunction
Postural muscles
135
______ lengthen and weaken in dysfunction
Phasic muscles
136
What are the postural muscles of the axioscapular muscles
Upper trap
Levator scapulae
Pec minor
137
What are the phasic muscles in the axioscapular muscles
Rhomboids
Middle trap
Lower trap
Serratus anterior
138
Postural muscles of the Scapulohumeral muscles
Subscapularis
139
What are the phasic muscles of the Scapulohumeral muscles
Deltoid
Supraspinatus
Infraspinatus
Teres minor
140
What are the postural muscles of the Axiohumeral muscles
Pec minor--clavicular portion
141
What are the postural muscle of the cervical and stromatgnathic muscles
Sternocleidomastoid
Suboccipitals
Scaleni
Supra hyoid
142
What are the phasic muscles for the cervical and stomatognathic muscles
Longus capitus
| Infra hyoid
143
What is the primary role of the axioscapular muscles
Position the scapula
144
What are the muscles of the axioscapular muscles
```
Trapezius
Serratus anterior
Levator scapulae
Rhomboids
Pectoralis minor
```
145
Muscles of the Axiohumeral group
Latissimus Dorsi
| Pectoralis major
146
Action of the trap
Upper fibers elevate
Middle fibers retract
Lower fibers depress
Upper and lower work together for upward rotation of the scapula
147
Weakness in _____ is seen with decreased elevation strength; depression, adduction and forward tilt of the scapula
Upper trapezius
148
______ weakness is seen with deceased scapular adduction and posture
Middle trap
149
______ weakness is when there is difficulty stabilizing the scapula during upward rotation
Lower trap
150
How can you tell if there is tightness in the upper traps
There is elevated shoulders or asymmetrical head positions, decreased neck rom, only upper is tight--upward rotation of the scapula
151
What are the actions of the serratus anterior
Scapular abduction and upward rotation = protraction
| And elevation
152
Weakness in the serratus is known as
Winging
153
Weakness in the serratus is seen when
During upward rotation (flexion, elevation or abduction)
Seen at rest or passively--restricted GH rom or postural abnormalities.
154
During winging the scapula is pushed into ____
Adduction
155
Serratus anterior weakness can also been seen as _____ with resisted shoulder _____
Winging
Flexion
156
What causes decreased shoulder medial rotation winging?
Not a result of serratus weakness. There is no full internal rotation because of compensation. The forward position of the scapula is the compensation. It is more tipped forward. This is due to tightness in structures and winging is the compensation
157
What is the action of the levator scapulae
Elevator and downward rotator
158
The levator is a _____ of the neck
Lateral flexor
159
What actions would you see weakness in if the levator was weak
Reaching back
Pulling
Rowing
160
If you have a weak levator what could posture look like
Round shoulders
161
If the levator was tight what would the scapula be doing
The scapula is tilted--the glenoid is downward and forward
162
Action of the rhomboids
Retract scapula
Downward rotation (to depress the glenoid cavity)
Fix scapula to the thoracic wall
163
How would weakness of the rhomboids present
Pulling behind back
Rowing
Round shoulders
Lateral rotation of scapula
164
Action of pec minor
Stabilizes the scapula by drawing it inferiorly and anteriorly against the thoracic wall
Scapular depression and downward rotation.
165
If the pec minor is weak there will be difficulty in what
Difficulty controlling shoulder during weight bearing.
166
How can you tell if the pec minor is tight
Anterior scapular tilt
Round shoulders
Increased internal rotation
Increased impingement
167
Action of the Latissimus dorsi
Extends adducts and internally rotates the humerus
Raises body towards the arms during climbing
Shoulder depression
168
Tightness in ______ limits shoulder rom in flexion and external rotation
Latissimus dorsi
169
How can you check for tightness in the Latissimus dorsi
Flexion in the upper t spine--supine, knees to chest and arms straight over Your head
170
Action of pec major
```
Flexion
Adduction
Internal rotation
Horizontal adduction of the arm
Clavicular--flexes humerus
Sternal--extends humerus
Attaches the trunk to the humerus
```
171
Tightness in the ______ limits rom in horizontal abduction and external rotation
Pec major
172
______ muscles working together to produce a purposeful movement
Functional movement
173
Axioscapular elevation is elevation of the _____ and _____
Scapula and clavicle
174
Axioscapular elevation is synergistic action of
Upper trap
| Levator scapula
175
What muscles do axioscapular depression
Scapular depressors
Lower trap--pulls scapula down
Latissimus dorsi--pulls scapula down
Pec minor--depresses scapula from the coracoid process
Humeral depressors
Latissimus dorsi
Pectoralis major
Both pull humerus down
176
What is the function of axioscapular depression
Closed chain scapular depression
Raise thorax on a fixed scapula.
177
What are some examples of axioscapular depression
Getting up from a wheelchair
Push up
Blocks
Crutch walking
178
What are the primary and secondary muscles of axioscapular retraction
Primary-- middle trap
Secondary-- lower trap and rhomboids
(Synergistic action between these two) they are upward and downward rotators
179
______ elevation of the rhomboids is neutralized by depression of the lower traps. The line of fives of both muscles combine, however, to produce pure retraction
Vigorous retraction.
180
Describe axioscapular protraction
Scapula--serratus anterior pulls the scapula forward
Humerus--pec major pulls the humerus and assists if the arm is at the side
181
What muscles produce upward rotation of the scapula
Upper and lower traps
| Serratus anterior
182
The ____ lifts up lateral clacivle and acromion process in upward rotation
Upper trap
183
______ pulls on the medial end of the spine and scapula in upward rotation
Lower trap
184
_____ pulls on the inferior angle of the scapula (where the majority of the fibers insert) to pull it laterally on the chest wall
Serratus anterior
185
The traps and serratus are a _____ in upward rotation of the scapula
Force couple
186
What muscles produce downward rotation of the scapula
Synergistic action of levator scapula, rhomboids, and pec minor
These are a force couple
187
What is the function of downward rotation of the scapula
Return from upward rotation
Swimming, crawling, pulling down the window
Shoulder adduction with extension
188
What axioscapular muscles do humeral extension
Rhomboids stabilize the scapula
Teres major and Latissimus dorsi extend the humerus
Active during upper extremity weight bearing
189
______ provide motion and dynamic stabilization to the GH joint
Scapulohumeral group
190
What are the Scapulohumeral muscles
```
Deltoid
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
Teres major
Corachobrachialis
```
191
Action of the deltoid
Entire muscle abducts the GH
Anterior: flexes and horizontal adduction with medial rotation of the arm
Middle: abducts the arm
Posterior: extends, laterally rotates the arm and horizontally abducts.
192
What would happen with deltoid paralysis
Supraspinatus would do abduction. It would elevate the arm by substitution of scapula upward rotation and lateral trunk flexion.
193
_____ weakness would cause decreased shoulder flexion strength, decreased internal rotation, abduction, and horizontal adduction
Anterior deltoid
194
_____ weakness would cause decreased shoulder abduction strength
Middle deltoid
195
_______ weakness should cause decreased shoulder extension strength
Posterior deltoid
196
______ tightness would cause decreased shoulder extension and external rotation rom
Anterior deltoid
197
_____ tightness would cause decrease shoulder adduction rom
Middle deltoid
198
____ would cause decreased shoulder flexion and internal rotation rom
Posterior deltoid
199
What is the action of the supraspinatus
Abduction of shoulder throughout rom
External rotation of the shoulder
Stabilizes GH joint
200
____ weakness would cause decreased strength and endurance of shoulder abduction
Supraspinatus
201
_____ tightness would cause decreased internal rotation with shoulder extension and decreased shoulder adduction across the plane of the body.
Supraspinatus
202
Action of teres minor and infraspinatus
Lateral rotation of GH
203
______ weakness would cause decreased strength of external rotation and shoulder impingement
Infraspinatus and teres minor
204
_______ tightness would cause decreased rom of shoulder internal rotation and horizontal adduction.
Infraspinatus and teres minor
205
______ tightness can cause closed kinetic chain winging
Teres minor and infraspinatus
206
Action of subscapularis
Medial GH rotation
207
______ weakness causes decreased strength of internal rotation and contributes to anterior instability of the GH joint and also causes shoulder impingement
Subscapularis
208
______ tightness would cause decreased external rotation rom
Subscapularis
209
action of teres major
Extends and medially rotates the arm
| Pulls scapula when humerus is fixed
210
______ weakness causes decreased strength in internal rotation, extension, and adduction
Teres major
211
_______ tightness causes restriction in shoulder rom-- external rotation, flexion, and abduction. Can be seen in resting position or at the st joint
Teres major
212
What muscles do glenohumeral flexion
Deltoid
Supraspinatus
Long head of the biceps
Coracobrachialis.
213
Muscles of full rom of glenohumeral flexion
Anterior deltoid
Coracobrachialis
Long head of biceps
214
Assists of glenohumeral flexion
Coracobrachialis and biceps- the First 90 degrees of flexion
215
What are the terminal GH flexors
Scapulothoracic abduction and upward rotation- necessary for the distal slide of the humeral head
216
What are the prime movers for flexion abduction and elevation
Deltoid and supraspinatus
217
What muscles initiate abduction and reach max emg at 90 degrees abducton
Deltoid and supraspinatus
218
Where are the deltoid and supraspinatus at their shortest length
90 degrees of abduction
219
____ activity in all rotator cuff muscles and deltoid throughout the range of active abduction.
EMG
220
Both ____ and _____ contribute to large compression components for GH stability
Deltoids and supraspinatus
221
What is the function of the supraspinatus
Stabilizing
222
______ synergistically contract continuously during flexion and abduction thereby eliminating external rotation and internal rotation components, depress the humeral head, and prevent humeral head compression from the unchecked Deltoid
Teres minor, infraspinatus, and subscapularis.
223
What are the regulators of dynamic stability
Deltoid
Supraspinatus
Subscapularis, infraspinatus, and teres minor
224
What does the deltoid do in regulating dynamic stability
Superior line of force rolls the humeral head upward
225
How does the supraspinatus regulate dynamic stability
Rolls the humeral head into abduction and compresses the joint (stability)
226
How do the infraspinatus, subscapularis, and teres minor regulate dynamic stability
They work synergistically--canceling IR and ER components
They have a downward translational force on the humeral head (slide)- counteract superior translation
227
What are the internal rotators
Subscapularis--pure ir
Teres major and Latissimus dorsi--it with adduction and extension
Pec major--ir with adduction
228
What muscles perform external rotation
Infraspinatus
Teres minor
Posterior deltoid
Supraspinatus can assist when GH is between neutral and full external rotation
229
When can the supraspinatus assist external rotation
When the GH is between neutral and full ER
230
What is the interrelationship of the shoulder girlie to the spine
Musculoskeletal
Biomechanical
Postural
Neurogenic
