S2_L2: Kinesiology of the Shoulder Complex

Question 1

TRUE OR FALSE: The muscle that is parallel to the movement is the one that is most activated. It’s always about the line or plane of movement to muscle fiber.

Answer 1

True

Question 2

TRUE OR FALSE: Elevation of the arm is always in relation to the trunk unless stated otherwise.

Answer 2

True

Note: As long as the trunk does not participate in the motion, the degree of elevation of arm from vertical and elevation of arm relative to the trunk will be the same.

Question 3

TRUE OR FALSE: The scapulohumeral rhythm is a combination of concomitant glenohumeral and scapulothoracic motion. It varies among individuals and external constraints, but in reality, there is no definitive scapulohumeral rhythm.

Answer 3

True

Question 4

It is the only muscle capable of producing simultaneous scapular upward rotation (prime mover), posterior tilting, and external rotation, and has the largest moment arms of any of the scapulothoracic muscles.

Answer 4

Serratus anterior

Note: It is also the primary stabilizer of the inferior angle and medial border of the scapula.

Question 5

Paralysis of this muscle results to scapular winging

Answer 5

serratus anterior (boxer’s muscle)

Question 6

____ occurs to maintain the contact of the scapula with the contour of the rib cage and to orient the glenoid fossa.

Answer 6

Scapular tilting

Question 7

During normal flexion or abduction of the arm, the scapula ____ tilts on the thorax as the scapula is upwardly rotating.

Answer 7

posteriorly

Question 8

TRUE OR FALSE: The orientation of the glenoid fossa is important for maintaining congruency with the humeral head; maximizing function of glenohumeral muscles, capsule and ligaments; maximizing stability of the glenohumeral joint; and maximizing available motion of the arm.

Answer 8

True

Question 9

TRUE OR FALSE: Elevation of the scapula in the thorax (e.g., shoulder shrug) can result in anterior tilting or tipping of the scapula.

Answer 9

True

Question 10

The greatest shear forces during humeral elevation typically occur between ___ degrees of elevation.

Answer 10

30-40

Question 11

Painful arc of motion between ___ degrees of elevation (flexion & abduction) may indicate the rotator cuff or biceps as the primary source of pain.

Answer 11

60-120

Note: Pain later in the range of motion may indicate acromioclavicular degeneration as the primary source of pain.

Question 12

TRUE OR FALSE: A force component parallel to the long bone has a stabilizing effect because the parallel component contributes to joint compression.

Answer 12

True

Question 13

Most frequently dislocated joint in the body

Answer 13

glenohumeral joint

Question 14

TRUE OR FALSE: Shoulder dislocations are usually anterior-inferior, but multi-directional.

Answer 14

True

Question 15

Most common because of the weakness of the rotator interval capsule, foramen of Weitbrecht, weak rotator cuff muscles, and tendency of humerus to shift anteriorly (anteversion of the scapula).
A. anterior shoulder dislocation
B. posterior shoulder dislocation
C. inferior shoulder dislocation

Answer 15

A. anterior shoulder dislocation

Question 16

Brought about by the pull of gravity, and weak supraspinatus, deltoids, rotator interval capsule support, and area on the superior aspect.
A. anterior shoulder dislocation
B. posterior shoulder dislocation
C. inferior shoulder dislocation

Answer 16

C. inferior shoulder dislocation

Question 17

A potential space between the superior and middle glenohumeral ligaments; thus accounts for the weak capsular region and anterior dislocations.

Answer 17

Foramen of Weitbrecht

Question 18

Area between the middle and inferior glenohumeral ligaments that is not a common problematic area

Answer 18

Foramen of Rouviere

Question 19

Enumerate the components of the rotator interval capsule (RIC)

Answer 19

superior glenohumeral ligament, superior joint capsule, and coracohumeral ligament

Question 20

Most functional activities of the shoulder happen in this shoulder motion

Answer 20

scaption/scapular abduction

Question 21

This structure is the osteoligamentous vault over the humeral head that forms the subacromial space, suprahumeral space, or supraspinatus outlet.

Answer 21

Coracoacromial/Suprahumeral Arch

Note: It is 10mm in healthy subjects with an adducted arm, 5mm in arm elevation.

Question 22

Enumerate the contents of the subacromial space, the region between the suprahumeral/coracoacromial arch and humeral head

Answer 22

1. subacromial bursa
2. rotator cuff tendons
3. portion of tendon of the long head of the biceps brachii

Note: These structures are protected superiorly from direct trauma by the coracoacromial arch. Contact of the humeral head with the undersurface of the arch can cause painful impingement or mechanical abrasion of the structures within the subacromial space.

Question 23

These bursae are very important in the shoulder complex because they separate the supraspinatus tendon and humeral head from the acromion, coracoid process, coracoacromial ligament, and deltoid muscle.

Answer 23

Subacromial and subdeltoid bursae

Note: The bursae are commonly continuous with each other and are collectively known as subacromial bursa.

Question 24

TRUE OR FALSE: The subacromial bursa permits smooth gliding between the humerus and supraspinatus tendon and surrounding structures. Interruption or failure of this mechanism is a common cause of pain.

Answer 24

True

Question 25

TRUE OR FALSE: The subacromial space is considered as a component of the glenohumeral joint rather than a separate joint.

Answer 25

True

Note: The subacromial or suprahumeral joint (or space) is also described as a functional joint which is formed by movement of the head of humerus below the coracoacromial arch.

Question 26

This structure is a false joint formed by the coracoid process, acromion, coracoacromial ligament, and inferior surface of acromioclavicular joint. It acts as a physical barrier to superior translatory forces acting on the humeral head, preventing it from dislocating superiorly.

Answer 26

Coracoacromial/Suprahumeral Arch

Note: The coracoacromial ligament connects the acromion and coracoid process and creates the subacromial space below these structures.

Question 27

This condition occurs with a narrowed subacromial space. It occurs most commonly secondary to inflammation or degeneration of the supraspinatus tendon.

Answer 27

Subacromial bursitis

Question 28

TRUE OR FALSE: In shoulder impingement syndromes due to a narrowed subacromial space, the supraspinatus tendon (supraspinatus impingement syndrome), subacromial bursa, or long head of biceps are the ones usually impinged.

Answer 28

True

Note: There is no one single reason why people develop impingement syndromes, there are multiple factors involved. If the reason is anatomical, surgery is the solution.

Question 29

TRUE OR FALSE: Below 60º or above 120º in relation to the painful arc of shoulder motion, the supraspinatus tendon has yet to rotate past the overlying acromion or has already rotated past it, respectively. In these ranges, the pain is minimized or decreased.

Answer 29

True

Note: Beyond 120º, the space is less narrowed (opening further) because the scapula moves more superiorly with clavicular elevation, which is why there is no more pain/reduces the pain for the patient.

Question 30

Enumerate the 3 functional reasons for a narrowed subacromial space

Answer 30

1. Repetitive shoulder motion (Leads to inflammation, fibrosis, and thickening of soft tissues; e.g., throwers & swimmers)
2. Abnormal scapular mechanics (E.g., inadequate posterior tilting or upward rotation of the scapula)
3. Poor humeral mechanics (I.e., inadequate rolling or gliding movements, excessive superior or anterior translation of humeral head)

Question 31

Enumerate the 4 anatomical reasons for a narrowed subacromial space

Answer 31

1. Shape of acromion process (a curved or hooped shape causes narrowing compared to a flat shape)
2. Another object occupies the space (e.g., bony spurs or osteophytes)
3. Large coracoacromial ligament (congenital)
4. Disproportionately large humeral head

Question 32

This muscle is the prime mover of glenohumeral flexion

Answer 32

Anterior deltoid

Question 33

These muscles are the prime movers of glenohumeral abduction

Answer 33

deltoid and supraspinatus

Question 34

Most vulnerable rotator cuff muscle to tensile overload and chronic overuse because it is either passively stretched or actively contracting; it also participates in humeral elevation.

Answer 34

Supraspinatus

Question 35

It is the combination of scapular, clavicular, and humeral motion that occurs when the arm is raised either forward or to the side; including sagittal plane flexion, frontal plane abduction, and all the motions in between.

Answer 35

Elevation

Question 36

This movement is a combination of upward rotation of the scapula, external rotation of the shoulder, and posterior tilting of the scapula.

Answer 36

Abduction

Question 37

TRUE OR FALSE: Motion of the scapula on the thorax normally contributes about one-third of the total shoulder complex motion necessary for arm elevation, whereas the glenohumeral joint contributes about two-thirds of the total motion.

Answer 37

True

Question 38

TRUE OR FALSE: Any motions of the scapula will influence glenohumeral joint function.

Answer 38

True

Question 39

modified T/F on shoulder complex

TRUE joints are glenohumeral, acromioclavicular & sternoclavicular jount

FALSE joints are scapulothoracic, subacromial space & suprahumeral joint

Answer 39

TT

• false joints have no anatomical relationship with each other

Question 40

modified T/F on shoulder complex

It is made up of humerus, scapula & clavicle for mobility/motion & not for stability

It is from the scapula through the acromion process & lateral aspect of clavicle

Answer 40

TT

Question 41

modified T/F

sternoclavicular joint is the articulation of medial aspect of clavicle & manubrium of sternum

It is a saddle joint (double condyloid joint)

Answer 41

TT

Question 42

modified T/F on sternoclavicular joint

the concave part is for protraction & retraction

the convex part is for elevation & depression

Answer 42

TT

Question 43

match the ff ligament

1. between 2 clavicle, touches manubrium & supports superior aspect of joint that restrict too much depression of the clavicle
2. found anterior & posterior that prevent too much ant/pos displacement of clavicle
3. found inferior to clavicle to prevent too much elevation of the clavicle

A. sternoclavicular ligament with capsule
B. costoclavicular ligament
C. interclavicular ligament

Answer 43

1. C
2. A
3. B

Question 44

which of the ff are true about sternoclavicular joint

A. Has THREE ROTATIONAL Degrees of freedom

B. Elevation / Depression (z axis)

C. Protraction / Retraction (y axis)

D. Anterior (when protracting) / Posterior (when elevating shoulder) Rotation (x axis)

E. All of the above

Answer 44

E

• B&C are osteokinematic (observable)
• D is arthrokinematic (not observable)

Question 45

modified T/F on Sternoclavicular Joint:

Clavicular rotation aids in scapular upward rotation and shoulder elevation

If there’s no clavicular rotation, then it limits shoulder complex elevation

Answer 45

TT

Question 46

modified T/F on Sternoclavicular Joint:

Controls for clavicular elevation & depression

Costoclavicular ligament controls elevation while superior interclavicular ligament controls depression

Answer 46

TT

Question 47

modified T/F

Sternoclavicular Joint have THREE TRANSLATORY Degree of freedom:
Anterior / Posterior, Superior / Inferior, Lateral / Medial

During horizontal abduction of shoulder, there’s a lateral translation while during horizontal adduction of shoulder, there’s a medial translation

Answer 47

TT

Question 48

modified T/F

acromioclavicular joint articulates in the acromion process of scapula & lateral aspect of clavicle

It allows scapular rotation/movement & is the site of force transmission from the UE going to the clavicle

Answer 48

TT

Question 49

modified T/F on coracoclavicular ligament

conoid is lateral & anteriorly located

trapezoid is medial & posteriorly located

Answer 49

FF

trapezoid is lateral & anteriorly located

conoid is medial & posteriorly located

Question 50

modified T/F

acromioclavicular (AC) capsule has weaker support & easily tears than sternoclavicular capsule

acromioclavicular joint is connected with AC capsule & prevents too much depression of scapula/clavicle

Answer 50

TT

Question 51

modified T/F on acromioclavicular disk

fibrocartilagenous disk that prevents friction & for shock absorption, lubrication, & inc. joint congruency

It is found between joints & not oblique shaped unlike sternoclavicular disk

Answer 51

TT

Question 52

which of the ff are true about Acromioclavicular Joint:

A. Has THREE ROTARY Degrees of Freedom(DOF)

B. Internal / External Rotation (y axis) [30°of motion]

C. Anterior / Posterior Tilting or Tipping (x axis) [60°of motion]

D. Upward / Downward Rotation (z axis) [30°of motion]

E. All of the above

Answer 52

E.

Question 53

modified T/F

anterior tilting/tipping is where the superior aspect of scapula moves backward

posterior tilting/tipping is where the superior aspect of scapula moves forward

Answer 53

FF

anterior tilting/tipping is where the superior aspect of scapula moves FORWARD

posterior tilting/tipping is where the superior aspect of scapula moves BACKWARD

Question 54

T/F
Acromioclavicular Joint has THREE TRANSLATORY DOF: Anterior / Posterior, Superior / Inferior &
Lateral / Medial

Answer 54

T

Question 55

which of the ff are true about Scapulothoracic Joint:

A. Articulation of scapula with the thorax

B. Not a true anatomic and synovial joint

C. Interdependent with AC and SC joints

D. all of the above

Answer 55

D

Question 56

the ff are resting position of Scapulothoracic Joint, EXCEPT:

A. 5cm from midline through 2nd-7th ribs

B. Internally rotated (35-45°) from coronal plane

C. Anteriorly tilted (10-15°) from vertical

D. Upwardly rotated (5-10°) from vertical

E. None of the above

Answer 56

E

Question 57

which of the ff are functions of the Scapulothoracic Joint:

A. Increases shoulder ROM for greater reach

B. Maintains favorable length-tension relationships for deltoid to function above 90° shoulder elevation for stability while moving

C. Provides GH stability (glenoid and humeral head alignment) for overhead activities

D. Shock absorption for FOOSH & Permits elevation of body (e.g. seated push-up, ambulating with crutches)

E. All of the above

Answer 57

E

Question 58

modified T/F on Scapulothoracic Joint:

THREE ROTARY DOF
- Upward / Downward Rotation
- Internal / External Rotation
- Anterior / Posterior Tilting/Tipping

TRANSLATORY DOF
- Elevation / Depression
- Protraction / Retraction

Answer 58

TT

Question 59

which of the ff are true about glenohumeral joint:

A. articulation is at the humeral head & glenoid fossa of scapula

B. Ball-and-Socket Synovial Joint (universal joint)

C. More Mobility than Stability which is why it’s prone to instability

D. Anteverted scapula with Humeral head in superior, medial, posterior direction

E. All of the above

Answer 59

E

• the direction of humeral head with anteverted scapula (resting position of scapula) will contribute to the stabilization of glenohumeral joint

Question 60

match the ff

1. Axis through humeral head and neck in relation to longitudinal axis through humeral shaft
2. 130-150° (120°) in frontal plane
3. Axis through humeral head and
   neck in relation to an axis through humeral condyles
4. 30° posterior

A. ANGLE OF INCLINATION
B. ANGLE OF TORSION

Answer 60

1. A
2. A
3. B
4. B

Question 61

modified T/F on GLENOID LABRUM

Enhances the depth and concavity of the glenoid fossa by 50%

Fibrous connective tissues are covered by cartilaginous tissue

Answer 61

TT

Question 62

the ff are Functions of glenoid labrum, EXCEPT:

A. Resistance to humeral head translation

B. Reduction of joint friction

C. Dissipation of joint contact forces

D. Attachment site of ligaments, joint capsule and tendons

E. None of the above

Answer 62

E

Question 63

modified T/F on GLENOHUMERAL CAPSULE

Taut superiorly to prevent humerus sliding downward & slack anteriorly and inferiorly with arm at dependent side to give more room to elevate shoulder

Tight at adduction and IR (close-packed position)

Answer 63

TF

Tight at ABDUCTION and ER (close-packed position)

Question 64

which of the ff are part of the GLENOHUMERAL LIGAMENTS

A. Superior, Middle, & Inferior Glenohumeral Ligaments

B. Foramen of Weitbrecht which is the space between superior & middle GH ligament that can cause anterior dislocation because of the weak joint capsule

C. Foramen of Rouviere which is the space between middle & inferior GH ligament

D. Coracohumeral Ligament from coracoid to humerus that prevents humerus from being pulled downwards & maintains the stabilization of the humerus in the joint

E. All of the above

Answer 64

E

Question 65

which of the ff are true about rotator interval capsule (RIC)

A. consists of superior GH ligament, superior joint capsule, & coracohumeral ligament

B. acts to stabilize humerus in place, prevents humerus from inferiorly sliding

C. bridges the space between supraspinatus & subscapularis muscles

D. no muscular support, so no dynamic stabilization, only static stabilization

E. all of the above

Answer 65

E

Question 66

which of the ff statements are incorrect

A. bursa prevents excessive frictional forces

B. acromion bursa is found below acromion process

C. subdeltoid bursa is found between deltoid & humerus

D. Subcoracoid bursa is found between subscapularis & coracoid process

E. Without the bursa, the muscles will generate too much friction when they contract & result in muscle tear

Answer 66

B.

*subacromial bursa is found below acromion process

Question 67

which the ff are true on Motions of Glenohumeral Joint:

A. Has THREE ROTATIONAL DOF

B. Flexion (90-120°) / Extension (50°) [sagittal]

C. Abduction / Adduction (arms in neutral/IR versus arms in ER) [frontal]

D. External / Internal Rotation → 130° of rotation at 90° abduction [transverse]

E. All of the above

Answer 67

E

Question 68

modified T/F

SCAPTION / SCAPULAR ABDUCTION is the Shoulder elevation in the plane of scapula

It occurs along sagittal & transverse planes when abducting shoulder diagonally

Answer 68

TF

It occurs along sagittal & FRONTAL planes when abducting shoulder diagonally

• most functional activities happen in caption

Question 69

modified T/F

Coracoacromial/Suprahumeral Arch forms the subacromial space

Subacromial bursa, Rotator cuff tendons & Long head of biceps
brachii can also be seen in the Coracoacromial/Suprahumeral Arch

Answer 69

TT

Question 70

modified T/F

Narrowed subacromial space causes Impingement syndromes, Subacromial bursitis & bicipital tendinitis.

painful arc is between 50-130°

Answer 70

TF

painful arc is between 60-120°

Question 71

which of the ff are anatomical factors that narrows subacromial space

A. shape of acromion process (curved, flat, hooked)

B. when another object occupies the space (bony spurs/osteophytes)

C. in born large coracoacromial ligament

D. large humeral head that push up the structures & narrows the space

E. All of the above

Answer 71

E

Question 72

the ff are functional factors that narrows subacromial space, EXCEPT:

A. repetitive motion like swimmers, throwers

B. abnormality of scapular mechanics (not moving properly/rhythmically with humerus)

C. poor humeral mechanics ( concave-convex function of humeral head is altered, inadequate rolling/gliding movements can narrow the area)

D. None of the above

Answer 72

D

Question 73

modified T/F

static stabilization is provided by ligaments, joint capsules & rotator interval capsule (RIC)

In the dependent arm position, the negative pressure creates a suction effect that’s created by the joint capsule & allows the static stabilization of the GH joint & maintain stability of the joint

Answer 73

TT

Question 74

which of the ff are true about Dynamic Stabilization in dependent arm position

A. relies on the muscle

B. capable of stabilizing humerus by counteracting inferior forces of gravity

C. supraspinatus is found superiorly that dynamically stabilizes humerus & prevents downward pull

D. The line of force is inwards to compress together the humeral head to glenoid fossa to provide stabilization

E. All of the above

Answer 74

E

Question 75

modified T/F

the short head of the biceps brachii tendon stabilizes the humerus & prevents the downward pull

Others are born with laxed rotator cuffs, deltoids, long head of biceps that results in the instability of the shoulder so they rely on dynamic stabilizers & need to further strengthen the muscles

Answer 75

FT

the LONG head of the biceps brachii tendon stabilizes the humerus & prevents the downward pull

Question 76

modified T/F on shoulder impingement syndrome

painful in 60-120° arc because it narrows the subacromial space that could impinge the bursa, long head of biceps & supraspinatus tendon

pain is reduce but is still there in less than 60° & more than 120°

Answer 76

TT

Question 77

modified T/F on AC joint degeneration/destruction of the cartilage & disc

there’s a direct bone to bone contact & it’s very painful

when its compressed by crossing arms in front/ sidelying on that side, it becomes very painful

Answer 77

TT

Question 78

which of the ff are true about bicipital tendonitis

A. attaches inferiorly in superior labrum & rim of glenoid fossa

B. inflamed when narrow subacromial space

C. injured by torn in superior labrum (SLAP lesion)

D. Done by repetitive movements & if the bursa is absent then the tendon will have a direct frictional force wit the bone & will tear/degenerate the tendon

E. if the transverse humeral ligament is torn then the tendon can easily be moved sideways that create friction with he tubercles

Answer 78

A.

attaches SUPERIORLY in superior labrum & rim of glenoid fossa

Question 79

modified T/F

anterior shoulder dislocation is common due to weak RIC, foramen of weitbrecht, & rotator cuff in which the anterversion of the scapula easily push humerus anteriorly

Inferior dislocation is due to pull of gravity, & weak supraspinatus, deltoid, RIC

Answer 79

TT

• most people with shoulder dislocation is antero-inferior

Question 80

which of the ff are SCAPULOHUMERAL
FUNCTION

A. Shoulder complex (especially GH and ST) acts in coordinated manner

B. Distributes motion between joints for greater ROM with less compromise in stability

C. Maintains glenoid fossa in optimal position in relation to humeral head to increase congruency

D. Permits good length-tension relationship of muscles (prevents active insufficiency of shoulder muscles)

E. All of the above

Answer 80

E

Question 81

which of the ff are true about SCAPULOHUMERAL RHYTHM

In shoulder elevation:
A. GH contributes 100-120° (flexion); 90-120° (abduction)

B. ST contributes 50-60°

C. Combined is 150-180° elevation

D. Overall ratio of 2° for GH and 1° for ST (2:1 ratio)

E. all of the above

Answer 81

E

Question 82

match the ff phase to its SCAPULOHUMERAL RHYTHM

1. Initial 60° of flexion; 30° of abduction (3:1 ratio)
2. Scapula seeking a position of stability (GH joint only, scapula isn’t moving)
3. At 30° abduction, 2:1 ratio begins
4. ST joint movement is increased with GH joint motion reduced (approaching 1:1)
5. More scapular motion at 80-140° abduction

A. Setting Phase
B. Mid portion phase
C. Later Phase

Answer 82

According to Inman et. al.

1. A
2. A
3. B
4. C
5. C

Question 83

which of the ff are true about SC & AC
CONTRIBUTIONS

A. Contributes to 60° of scapular upward rotation since when we elevate GH complex, the scapula needs to move too

B. ST elevation results in SC
elevation & clavicular posterior rotation

C. SC in retraction

D. AC in internal rotation

E. All of the above

Answer 83

E

Question 84

identify the wrong statement

A. upper part of trapezius is an upward scapula rotator

B. levator scapula is a downward rotator with retraction of scapula

C. serratus anterior is an upward rotator with protraction of scapula

D. if same muscles are contracting on the same direction, they’ll move/create motion

E. if same muscles are contracting on the opposite direction, they’ll create stabilization on the scapula

Answer 84

B.

rhomboids is a downward rotator with retraction of scapula

Question 85

modified T/F

when upper trapezius & serratus anterior contract, the scapula will move upward

If you have a serratus anterior movement with the co-contraction of rhomboids, then the scapula is stabilized due to the stabilizing synergistic function of the muscles

Answer 85

TT

Question 86

modified T/F

SHOULDER COMPLEX DEPRESSION is when there’s a forceful downward movement of arm in relation to trunk (scapula rotates downward and adducts)

the shoulder complex is depressing while elevating trunk when lifting body in seated position, seated push-up (inc. tone of latissimus dorsi)

Answer 86

TT

Question 87

match the ff muscles
(can have multiple answers)

1. agonist in shoulder complex depression
2. synergist with latissimus dorsi
3. secondary agonist
4. aside from rotating scapula downward & adducting, the humerus will extend, adduct & IR
5. adducts & IR humerus

A. Latissimus Dorsi
B. Pectoralis Major (Sternal)
C. Teres Major
D. Rhomboids
E. Pectoralis Minor

Answer 87

1. A
2. D
3. B, C, E
4. A
5. B

Question 88

match the ff muscles

1. secondary role that anteriorly tilts scapula only for assistance
2. downward rotator of scapula, scapular downward rotation & adduction together with GH extension, adduction, IR which is a synergistic action
3. extensor, adductor, IR of humerus (secondary actor because it only activates if there’s resistance)

A. Latissimus Dorsi
B. Pectoralis Major (Sternal)
C. Teres Major
D. Rhomboids
E. Pectoralis Minor

Answer 88

1. E
2. D
3. C