Ptha 1413 - Functional Anatomy - Mansfield And Neumann Book And Miele Lecture - Exam 2

Front 1

What bones comprise the shoulder complex? ***

Back 1

- clavicle
- scapula
- humerus
- sternum
- ribcage

Front 2

For what action is the shoulder complex responsible? ***

Back 2

movement of hand through space

Front 3

How does the shoulder complex exhibit dynamic stability? ***

Back 3

- provides mobility for the hand to move and function through a large ROM

- provides a stable base on which that mobility occurs

Front 4

The shoulder complex is comprised of what two elements? ***

Back 4

- shoulder girdle

- shoulder joint

shoulder girdle + shoulder joint = shoulder complex

Front 5

What elements comprise the shoulder girdle? ***

Back 5

- scapula
- clavicle

Front 6

Name the joints of the shoulder girdle ***

Back 6

- AC joint

- SC joint

Front 7

What motions is the shoulder girdle capable of completing? ***

Back 7

- elevation/depression
- upward/downward rotation
- protraction/retraction

Front 8

What elements comprise the shoulder joint? ***

Back 8

- scapula

- humerus

Front 9

What is the name of the shoulder joint? ***

Back 9

glenohumeral joint

Front 10

What actions is the shoulder joint capable of performing? ***

Back 10

- flexion/extension
- internal/external rotation

- abduction/adduction
- horizontal abduction/adduction

Front 11

List the four joints of the shoulder complex ***

Back 11

- sternoclavicular (SC) joint
- acromioclavicular (AC) joint
- glenohumeral (GH) joint
- scapulothoracic (ST) joint*

* not a true joint--movement of the scapula over the posterior rib cage

Front 12

Which ligament covers the biceps tendon? ***

Back 12

transverse ligament

Front 13

What are the two components of the coracoclavicular ligament? ***

Back 13

- conoid ligament

- trapezoid ligament

Front 14

Where does the medial (sternal) end of the clavicle articulate? ***

Back 14

with the manubrium and first costal cartilage

Front 15

What is the only direct bony attachment of the upper extremity/shoulder complex to the axial skeleton? ***

Back 15

sternoclavicular joint

Front 16

What type of joint is the sternoclavicular joint? ***

Back 16

it is labeled as a plane or a saddle joint

Front 17

How many degrees of freedom does the sternoclavicular joint have and what movements can it make? ***

Back 17

3

- clavicle elevation/depression
- clavicle protraction/retraction
- clavicle rotation

Front 18

Is the SC joint commonly dislocated? Why? ***

Back 18

no, rarely

although the articulating surfaces are incongruent and therefore the joint is potentially unstable, it is well reinforced with:
- strong capsule
- intra-articular disc
- 3 strong ligaments

Front 19

Location and composition of the sternoclavicular ligament ***

Back 19

contains anterior and posterior fibers joining the clavicle to the manubrium

Front 20

Location and composition of the SC joint capsule ***

Back 20

- surrounds the entire joint
- reinforced by the anterior and posterior sternoclavicular joint ligaments

Front 21

Location and function of the interclavicular ligament ***

Back 21

- spans the jugular notch, connecting the superior medial aspects of the clavicles

- limits clavicular depression

Front 22

Location and function of the costoclavicular ligament ***

Back 22

- attaches the clavicle to the costal cartilage of the first rib

- limits extremes of clavicular motion except depression

Front 23

Function of the articular disc of the SC joint ***

Back 23

- absorbs shock between the clavicle and the sternum

- helps improve joint congruency

Front 24

Plane of motion and ROM for elevation and depression of the SC joint ***

Back 24

- near-frontal plane movement

allows roughly
- 45 degrees of clavicular elevation and
- 10 degrees of depression

Front 25

Plane of motion and ROM for protraction and retraction of the SC joint ***

Back 25

- horizontal plane about a vertical axis of rotation

allows about
- 15 to 30 degrees of clavicular motion in either direction

Front 26

Describe the rotational movement of the SC joint ***

Back 26

- clavicle rotates posteriorly about its longitudinal axis (then returns to normal)

- during shoulder abduction (and flexion per the book), the coracoclavicular ligament (assuming the conoid ligament?) becomes taut and spins the clavicle posteriorly

- clavicle rotates anteriorly back to its rest position as the shoulder is extended or adducted

Front 27

Location and purpose of the acromioclavicular (AC) joint ***

Back 27

- lateral (acromial) end of clavicle articulates with acromion process of scapula

- links the motion of the scapula (and attached humerus) to the lateral end of the clavicle

Front 28

Type of joint and degrees of freedom of AC joint ***

Back 28

- plane/gliding, synovial joint

- three degrees of freedom

Front 29

Motions of the AC joint ***

Back 29

- motion is minimal but necessary for normal shoulder motion; helps fine-tune movements between scapula and humerus

- scapular upward and downward rotation (coronal plane with sagittal/A-P axis)

- scapular winging (posterior movement of medial border with vertical axis through AC joint) occurs in transverse/horizontal plane * (a.k.a. horizontal plane adjustments)

- scapular tipping (posterior movement of inferior angle with coronal axis) occurs in sagittal plane (a.k.a. sagittal plane adjustments)

* fixed this from the slides, which had the same description for both winging and tipping

Front 30

Ligaments reinforcing the AC joint ***

Back 30

weak, loose capsule is reinforced by several ligaments

- acromioclavicular ligament (superior and inferior)
- coracoclavicular ligament (conoid and trapezoid)
- coracoacromial ligament

Front 31

Which joint is stronger, AC or SC? ***

Back 31

SC

(dislocations or shoulder separations at the AC joint are common)

Front 32

Supporting ligaments of the AC joint: ***

Back 32

- acromioclavicular ligament
- coracoclavicular ligament (conoid and trapezoid)
- coracoacromial ligament

Front 33

Location and function of the acromioclavicular ligament ***

Back 33

- joins the clavicle to the acromion
- helps prevent dislocations of the scapula
- links motion of scapula to clavicle—or vice versa

Front 34

Location, composition, and function of the coracoclavicular ligament ***

Back 34

- joins the coracoid process to the clavicle
- composed of the conoid and trapezoid ligaments
- helps suspend the scapula from the clavicle and prevents inferior acromial dislocation

Front 35

Location and function of the coracoacromial ligament ***

Back 35

- attaches the coracoid process to the acromion process
- part of the coracoacromial arch—a functional “roof” that protects the head of the humerus (needs to stay open due to bursa within—subacromial space)

Front 36

What is the purpose of the articular disc of the AC joint? ***

Back 36

- improves joint congruency

- helps to absorb the compressive forces

(These are the purposes of all articular discs!)

Front 37

Motions allowed by the AC joint ***

Back 37

allows motion in all three planes:

- upward and downward rotation (frontal/coronal)
- rotation in the horizontal plane (winging)
- rotation in the sagittal plane (tipping)

Front 38

Description of the ST joint ***

Back 38

- articulation between scapula and posterior thorax

- scapula slides over posterior ribcage

- not a true joint, no point of fixation

Front 39

Is the ST joint a true joint? ***

Back 39

no, there is no point of fixation

Front 40

What forces hold the scapula to the thorax? ***

Back 40

- muscles

- atmospheric pressure

Front 41

The only connection the scapula has with the axial skeleton is the ______ ***

Back 41

clavicle

Front 42

The SC, AC and ST joints form a _______ kinematic chain. ***

Back 42

closed

movement at one point affects movements at the other

Front 43

Function of the ST joint/articulation ***

Back 43

- orient glenoid fossa for optimal UE movement

- along with scapular muscles, provides a stable base for articulation of humeral head

Front 44

Motions at the ST joint ***

Back 44

- elevation and depression
- protraction and retraction (abduction and adduction)
- upward and downward rotation (of glenoid fossa)

Front 45

Description of the glenohumeral (GH) joint ***

Back 45

articulation of head of humerus with glenoid fossa of scapula

Front 46

Type of joint and degrees of freedom for GH joint ***

Back 46

- synovial, ball-and-socket joint

- three degrees of freedom

Front 47

Possible motions of the GH joint ***

Back 47

- flexion/extension
- abduction/adduction

- external/internal rotation
- horizontal abduction/adduction (combination of flex/abd/add)

- circumduction (combination of flex/ext/abd/add)

Front 48

What is required to happen for full abduction of the GH joint to occur? ***

Back 48

the humerus must be externally rotated to avoid impingement of the greater tubercle/bursa after approximately 90-130 degrees of abduction

Front 49

What construction enhances the depth of the glenoid fossa? ***

Back 49

the glenoid labrum

Front 50

Purpose of bursae ***

Back 50

allow for smooth gliding between structures and decrease friction

Front 51

The main bursa in the GH joint ***

Back 51

subacromial bursa

separates head of humerus and supraspinatus tendon from deltoid muscle and acromio-corocoid process/coracoacromial ligament

Front 52

Describe the structure and purpose of the coracoacromial arch ***

Back 52

composed of
- acromion
- coracoid process
- coracoacromial ligament

- prevents dislocation of the humeral head superiorly

Front 53

What is the rotator cuff? ***

Back 53

a musculotendinous cuff around the joint capsule formed by the blending together of the insertions of the:
--- teres minor
--- infraspinatus
--- supraspinatus
--- subscapularis muscles
(which originate from the scapula and insert around the humeral head)

RC supplies a large compression force and negates upward translatory dislocation force of deltoid pull

Front 54

How do the muscles of the rotator cuff work together? ***

Back 54

muscles (infraspinatus, subscapularis, teres minor) contract synergestically to keep head of humerus rotating against glenoid fossa during joint motion by deltoid and supraspinatus muscles which create a translatory, dislocating rather than stabilizing effect (upwardly)

Front 55

Describe GH joint (inferior) subluxation ***

Back 55

passive tension on supraspinatus muscle and coracohumeral ligament, supporting GH capsule is created when arm is hanging dependent at side

-subluxation of GH joint inferiorly occurs with patients who have suffered stroke (CVA)

- results in paralysis of shoulder muscles/RC 2-3 finger subluxation is severe

Front 56

What patients are at risk of developing (inferior) GH joint subluxation? ***

Back 56

CVA patients

Front 57

What is the scapulohumeral rhythm? ***

Back 57

- shared movement of the GH and ST joints at a 2:1 ratio to complete full ROM for shoulder flexion or abduction


--------the following statements from the slide show throw the math off *-------

- first 30-60 degrees of shoulder abduction or flexion are pure GH joint movement

- after that for every 2 degrees of GH movement there is 1 degree of ST movement (upward rotation of scapula) overall ratio of 2:1


* if the first 60 degrees are pure GH, then AFTER that the ratio is 2:1, the overall ratio CANNOT be 2:1

180 (total degrees) - 60 (initial GH degrees) = 120 (degrees remaining)
2:1 ratio for remaining 120 degrees = 80:40
totals 140:40, which is > 3:1

the GH needs to slow, the ST needs to pick up the difference to produce a 120:60 degree ratio (2:1)

Could probably be the first 60 degrees is pure GH, then after that it is 1:1 GH:ST for an overall of 2:1

Front 58

What is the purpose of the scapulohumeral rhythm? ***

Back 58

- Maintain glenoid fossa in optimal position to increase ROM of shoulder (as scapula upwardly rotates so does glenoid fossa)

- Permit the muscles acting on the humerus to maintain a good length-tension relationship

Front 59

ST joint movement (thus the scapulohumeral rhythm) requires invovlvement of the _________ because the ST joint is part of a closed kinematic chain. ***

Back 59

AC and SC joints

(per the book, each contributes about half of the scapular movement, i.e., 30 degrees each for the 60 degrees of scapular upward rotation carried out in 180 degrees of shoulder flexion or abduction)

Front 60

Will disruption of movement in the AC or SC joint cause a loss of shoulder ROM? ***

Back 60

yes, because the SC and AC joints are part of a closed kinematic chain with the ST joint

Front 61

What is a force couple? ***

Back 61

muscles pulling in equal and opposite but parallel directions in order to accomplish a rotational motion of the bone

Front 62

Movements of the shoulder complex require ___ movement and ___ movement. ***

Back 62

- GH joint
- ST joint

(thus also AC joint and SC joint movement b/c of the closed kinematic chain with the ST joint)

Front 63

Shoulder movements of elevation?

Depression? ***

Back 63

- abduction (protraction), flexion, scapular upward rotation

- adduction (retraction), extension, scapular downward rotation

Front 64

What are the two primary groups of muscles involved in shoulder movement? ***

Back 64

- scapular movers

- humeral movers

Front 65

Scapular (prime) movers ***

abduction (protraction)

Back 65

- serratus anterior
- pectoralis minor

Front 66

Scapular (prime) movers ***

adduction (retraction)

Back 66

- rhomboid (major)
- middle trapezius

Front 67

Scapular (prime) movers ***

elevation

Back 67

- upper trapezius
- levator scapulae

Front 68

Scapular (prime) movers ***

depression

Back 68

- lower trapezius
- pectoralis minor

Front 69

Scapular (prime) movers ***

upward rotation

Back 69

- upper trapezius
- lower trapezius
- serratus anterior
(force couple!!)

Front 70

Scapular (prime) movers ***

downward rotation

Back 70

- pectoralis minor
- rhomboids
- levator scapula
(force couple!!)

Front 71

Divisions of the trapezius and their functions ***

Back 71

- upper (elevation, upward rotation)
- middle (retraction)
- lower (depression, upward rotation)

upper/lower
- agonistic for upward rotation
- antagonistic for elevation and depression

Front 72

Levator scapulae function and uses ***

Back 72

- elevation
- downward rotation

- carrying heavy bag on shoulder/in hand
- shrugging (with upper trapezius)

Front 73

Rhomboids function ***

Back 73

- retraction (adduction)
- downward rotation

- major and minor (considered one muscle)

Front 74

Serratus anterior function ***

Back 74

- protraction (abduction)
- upward rotation

- prevents scapular winging
- necessary for full shoulder flexion

Front 75

Pectoralis minor function ***

Back 75

- downward rotation
- depression
- protraction (abduction)

Front 76

Scapular upward rotation accompanies what two motions? ***

Back 76

- shoulder flexion
- shoulder abduction

Front 77

Scapular downward rotation accompanies what movement? ***

Back 77

shoulder extension

Front 78

Humeral (prime) movers ***

flexion

Back 78

- anterior deltoid
- pectoralis major (clavicular head)

Front 79

Humeral (prime) movers ***

extension

Back 79

- posterior deltoid
- latissimus dorsi
- teres major (lat's little helper)
- pectoralis major
- infraspinatus

Front 80

Humeral (prime) movers ***

abduction

Back 80

- middle deltoid
- supraspinatus

Front 81

Humeral (prime) movers ***

adduction

Back 81

- pectoralis major
- latissimus dorsi
- teres minor (major?)

Front 82

Humeral (prime) movers ***

horizontal abduction

Back 82

- posterior deltoid
- infraspinatus
- teres minor

Front 83

Humeral (prime) movers ***

horizontal adduction

Back 83

- anterior deltoid
- pectoralis major

Front 84

Humeral (prime) movers ***

internal (medial) rotation

Back 84

- subscapularis
- latissimus dorsi
- teres major
- pectoralis major
- anterior deltoid

Front 85

Humeral (prime) movers ***

external (lateral) rotation

Back 85

- infraspinatus
- teres minor
- posterior deltoid

Front 86

Anterior deltoid function ***

Back 86

- flexion
- internal rotation
- horizontal adduction

Front 87

Middle deltoid function ***

Back 87

abduction

Front 88

Posterior deltoid function ***

Back 88

- extension/hyperextension
- external rotation
- horizontal abduction

Front 89

How does the scapulohumeral rhythm affect the (middle) deltoid during shoulder abduction? ***

Back 89

because of the SH rhythm, the middle deltoid is able to maintain near optimal length for most of the contraction

(otherwise it would run out of contractile power at about 90 degrees abduction; with the upward rotation of the scapula, the origin of the middle deltoid moves away from the insertion)

Front 90

Why is the deltoid strongly dependent on an intact RC during shoulder flexion or abduction? ***

Back 90

to keep the head of the humerus against the glenoid fossa

Front 91

Supraspinatus action ***

Back 91

- shoulder abduction (most effective during first 60 degrees)

- as an RC component, stabilizes head of humerus against glenoid fossa

Front 92

Pectoralis major action ***

Back 92

- shoulder adduction
- shoulder internal rotation
- shoulder horizontal adduction

- antagonist to shoulder flexion/extension
- agonist with adduction, IR and horizontal adduction

Front 93

Two divisions of pectoralis major muscle and their actions ***

Back 93

- clavicular portion - flexion of extended shoulder

- sternal portion - extension of flexed shoulder

Front 94

Latissimus dorsi function ***

Back 94

- shoulder extension/hyperextension
- shoulder adduction
- shoulder IR

reverse action
- elevation of pelvis
- stabilizing UE in crutch ambulation

Front 95

Infraspinatus function ***

Back 95

- shoulder ER
- shoulder horizontal abduction

Front 96

Which muscle is latissimus dorsi's "little helper"? ***

Back 96

teres major

performs same actions as latissimus dorsi except hyperextension

Front 97

Teres minor function ***

Back 97

- works with infraspinatus
- shoulder ER
- shoulder horizontal abduction

- component of RC

Front 98

Subscapularis function ***

Back 98

- shoulder IR

- component of RC

Front 99

What is the purpose of the rotator cuff? ***

Back 99

- cover the humeral head

- hold the humeral head against the glenoid fossa during shoulder movements

Front 100

List three humeral (assistive) movers ***

Back 100

- coracobrachialis
- biceps brachii
- triceps brachii

Front 101

Coracobrachialis function in shoulder movement ***

Back 101

- assists with shoulder flexion and adduction
- has almost vertical line of pull

- most force is directed back into joint (shunt muscle)
- stabilizes shoulder joint

Front 102

Biceps and triceps function in shoulder movement ***

Back 102

- two-joint muscles that assist at the shoulder

- primary movers with elbow actions

Front 103

What structure innervates the entire upper extremity? ***

Back 103

brachial plexus

Front 104

The majority of shoulder complex muscles are innervated from what two brachial plexus regions? ***

Back 104

- nerves that branch from the posterior cord (axillary, radial, thoracodorsal, subscapular, etc.)

- nerves branching from the more proximal segments of the plexus (dorsal scapular, long thoracic, pectoral, suprascapular, etc.)

Front 105

What muscle is the UE exception to innervation by the brachial plexus? ***

Back 105

the trapezius

(innervated primarily by cranial nerve XI - accessory nerve)

Front 106

In the shoulder complex (GH joint), a superior roll without an inferior slide produces.... ***

Back 106

impingement of the subacromial bursa and supraspinatus muscle
(at apparently 22 degrees of abduction per the picture?)

Front 107

Which of the following statements is true regarding upward rotation of the scapula: ***

a. occurs as a natural component of shoulder extension
b. occurs as a natural component of raising one's arm overhead
c. occurs primarily through activation of the teres major and teres minor muscles
d. results in the inferior tip of the scapula pointing medially

Back 107

b. occurs as a natural component of raising one's arm overhead

Front 108

Which of the following statements is true regarding the glenohumeral joint? ***

a. the glenohumeral joint has a ball-and-socket joint structure
b. the glenohumeral joint allows motion in all three planes
c. the glenohumeral joint is formed by the greater tubercle articulating with the distal clavicle
d. a and b
e. all of the above

Back 108

d. a and b

Front 109

Which of the following joints is a saddle joint? ***

a. glenohumeral
b. sternoclavicular
c. acromioclavicular
d. scapulothoracic

Back 109

b. sternoclavicular

Front 110

Without upward rotation of the scapula, full shoulder abduction would be limited to approximately: ***

a. 60 degrees
b. 80 degrees
c. 120 degrees
d. 170 degrees

Back 110

c. 120 degrees

Front 111

The acromion is a structure associated with which bone? ***

a. humerus
b. scapula
c. clavicle
d. sternum

Back 111

b. scapula

Front 112

A muscle that performs shoulder flexion ***

a. must have a line of pull anterior to the medial-lateral axis of rotation of the shoulder
b. must course posterior to the medial-lateral axis of rotation of the shoulder
c. must also extend the elbow
d. is likely innervated by the radial nerve

Back 112

a. must have a line of pull anterior to the medial-lateral axis of rotation of the shoulder

Front 113

Which of the following best describes the scapulohumeral rhythm? ***

a. for every 3 degrees of scapular upward rotation, 1 degree of glenohumeral adduction must occur
b. for every 2 degrees of glenohumeral flexion or abduction, 1 degree of scapular upward rotation must occur
c. the scapulohumeral rhythm only occurs during passive flexion and extension motions of the shoulder
d. protraction of the scapula must be accompanied by horizontal abduction of the humerus

Back 113

b. for every 2 degrees of glenohumeral flexion or abduction, 1 degree of scapular upward rotation must occur

Front 114

Which of the following muscles is not part of the force-couple that produces upward rotation of the scapula? ***

a. serratus anterior
b. upper trapezius
c. rhomboids
d. lower trapezius

Back 114

c. rhomboids

Front 115

Which of the following muscles does not attach to the humerus (proximally or distally)? ***

a. teres minor
b. anterior deltoid
c. serratus anterior
d. subscapularis

Back 115

c. serratus anterior

Front 116

Which of the following muscles is not part of the rotator cuff? ***

a. supraspinatus
b. teres minor
c. infraspinatus
d. upper trapezius

Back 116

d. upper trapezius

Front 117

Winging of the scapula is indicative of: ***

a. anterior deltoid weakness
b. posterior deltoid weakness
c. serratus anterior weakness
d. teres major and latissimus dorsi weakness

Back 117

c. serratus anterior weakness

Front 118

Which of the following statements is true regarding shoulder depression? ***

a. incorporates scapulothoracic depression and glenohumeral depression
b. can be used in a closed chain to elevate the trunk
c. relies mostly on the combined action of the upper and middle trapezius muscles
d. a and b
e. b and c

Back 118

d. a and b

Front 119

Which of the following statements is true regarding the deltoid muscles? ***

a. the anterior deltoid performs shoulder flexion
b. the posterior deltoid performs shoulder extension
c. all heads of the deltoid are innervated by the axillary nerve
d. a and c
e. all of the above

Back 119

e. all of the above

Front 120

What is the common similarity among the latissimus dorsi, posterior deltoid, and long head of the triceps? ***

a. all three of these muscles attach to the humerus
b. all three of these muscles are strong internal rotators of the shoulder
c. all three of these muscles are innervated by the radial nerve
d. all three of these muscles can extend the shoulder

Back 120

d. all three of these muscles can extend the shoulder

Front 121

Which of the following describes the common function of the rotator cuff muscles? ***

a. all four muscles perform internal rotation of the shoulder
b. all four muscles help to stabilize the humeral head within the glenoid fossa
c. all four muscles produce a force-couple that upwardly rotates the scapula
d. all four muscles prevent excessive external rotation of the glenohumeral joint

Back 121

b. all four muscles help to stabilize the humeral head within the glenoid fossa

Front 122

If the shoulder is abducted to 150 degrees, according to the scapulohumeral rhythm, how much upward rotation of the scapula has occurred? ***

a. 50 degrees
b. 100 degrees
c. 120 degrees
d. 25 to 30 degrees

Back 122

a. 50 degrees

Front 123

Impingement can best be described as: ***

a. reduced activation of the internal rotators of the shoulder
b. a superior migration of the humerus resulting in the humeral head colliding with the acromion
c. the combined actions of scapular depression and glenohumeral protraction
d. complete rupture of the acromioclavicular and coracoclavicular ligaments

Back 123

b. a superior migration of the humerus resulting in the humeral head colliding with the acromion

Front 124

Performing abduction in the scapular plane helps avoid impingement because: ***

a. the teres minor and teres major are put on slack
b. the greater tuberosity is positioned under the highest point of the acromion
c. the scapula becomes fixed to the medial aspect of the posterior thorax
d. the subscapularis becomes an external rotator of the shoulder in this position

Back 124

b. the greater tuberosity is positioned under the highest point of the acromion

Front 125

Which of the following muscles is not an internal rotator of the shoulder? ***

a. pectoralis major
b. latissimus dorsi
c. infraspinatus
d. teres major

Back 125

c. infraspinatus

Front 126

Which of the following statements is true regarding external rotation of the shoulder: ***

a. occurs in frontal plane
b. occurs about a longitudinal axis of rotation
c. performed by two of the four rotator cuff muscles
d. a and c
e. b and c

Back 126

e. b and c

Front 127

The serratus anterior is a primary upward rotator of the scapula. ***

a. true
b. false

Back 127

a. true

Front 128

A muscle that performs glenohumeral abduction must have a line of pull superior to the anterior-posterior axis of rotation. ***

a. true
b. false

Back 128

a. true

Front 129

The shoulder complex is equipped with more external rotators than internal rotator muscles. ***

a. true
b. false

Back 129

b. false (only 2 primary external rotators--infraspinatus and teres minor)

Front 130

During abduction of the shoulder, the arthrokinematic roll and slide occur in the same direction. ***

a. true
b. false

Back 130

b. false (convex on concave = roll and slide in opposite directions)

Front 131

The latissimus dorsi and lower trapezius often work together to depress the entire shoulder. ***

a. true
b. false

Back 131

a. true

Front 132

Horizontal abduction of the humerus is generally accompanied by retraction of the scapula. ***

a. true
b. false

Back 132

a. true

Front 133

The supraspinatus and the middle deltoid are both innervated by the same nerve. ***

a. true
b. false

Back 133

b. false (supraspinatus = suprascapular nerve, middle deltoid = axillary nerve)

Front 134

The rhomboids and pectoralis minor are primary downward rotators of the scapula. ***

a. true
b. false

Back 134

a. true

Front 135

A pulling motion such as a "wide-grip pull-up" will involve strong activation of the latissimus dorsi. ***

a. true
b. false

Back 135

a. true

Front 136

Shoulder impingement is likely to occur if the scapula does not upwardly rotate as the shoulder is actively abducted. ***

a. true
b. false

Back 136

a. true

Front 137

Within the shoulder, paralysis, weakness, or tightness of any single muscle can....

Back 137

disrupt the natural kinematic sequencing of the entire shoulder complex

Front 138

Ribs that attach to the body of the sternum

Back 138

2 - 7

Front 139

Superior and inferior glenoid tubercles (a.k.a. supraglenoid and infraglenoid tubercles) serve as attachment points for what muscles?

Back 139

- long head of biceps (superior)

- long head of triceps (inferior)

Front 140

What structures form a "roof" over the humeral head (coracoacromial arch)?

Back 140

- acromion process

- coracoacromial ligament

Front 141

Why is the inferior angle of the scapula clinically important?

Back 141

it helps track scapular motion

Front 142

What is the radial (spiral) groove of the humerus?

Back 142

a groove that runs obliquely along the posterior surface of the humerus

the radial nerve follows this groove, and helps define the proximal attachment for the lateral and medial heads of the triceps

Front 143

Of what motions is the SC joint capable?

Back 143

- elevation/depression
- protraction/retraction
- axial rotation

Front 144

In essence, all movements of the shoulder girdle (i.e., scapula and clavicle) originate at the

Back 144

SC joint

(thus a fused SC joint would significantly limit movement of the clavicle and scapula and thus limit movement of the entire shoulder)

Front 145

What is unique about the coracoacromial ligament?

Back 145

it is one of the few ligaments of the body that attach both proximally and distally to the same bone

Front 146

What is the primary stabilizing force of the GH joint?

Back 146

the surrounding musculature (particularly the rotator cuff muscles)

this is due to the fact that the ligaments and capsule of the GH joint are relatively thin and provide only secondary stability to the joint

Front 147

List the joints of the shoulder complex

Back 147

- SC joint
- ST joint
- AC joint
- GH joint

Front 148

List the supporting structures of the SC joint

Back 148

- SC ligament
- joint capsule
- interclavicular ligament (spans jugular notch, connects the clavicles)
- costoclavicular ligament
- articular disc

Front 149

List the supporting structures of the AC joint

Back 149

- AC ligament (links motion of scapula to clavicle)
- coracoclavicular ligament (conoid and trapezoid)
- coracoacromial ligament (with acromion process forms coracoacromial arch)

Front 150

List the supporting structures of the GH joint

Back 150

- rotator cuff
- capsular ligaments (superior/middle/inferior GH ligaments)
- coracohumeral ligament (coracoid to greater tubercle)
- glenoid labrum (doubles the depth)
- long head of biceps (stabilizes anteriorly)

Front 151

Describe impingement

Back 151

- convex head of humerus rolls superiorly without corresponding inferior slide

- humeral head jams into acromion

- damage to supraspinatus muscle and/or subacromial bursa

Front 152

Plane of motion, axis of rotation and ROM for flexion and extension of the GH joint

Back 152

- sagittal plane
- medial-lateral axis

- 120 degrees of flexion (180 with scapular upward rotation)
- 45 degrees of extension

Front 153

Normal kinematic interactions of scapula, humerus, and clavicle for: horizontal abduction

Back 153

- horizontal abduction of humerus
- retraction of scapula
- retraction of clavicle

Front 154

Normal kinematic interactions of scapula, humerus, and clavicle for: horizontal adduction

Back 154

- horizontal adduction of humerus
- protraction of scapula
- protraction of clavicle

Front 155

Normal kinematic interactions of scapula, humerus, and clavicle for: shoulder flexion

Back 155

- 2:1 scapulohumeral rhythm of:
-- flexion of humerus
-- upward rotation of scapula
- elevation and posterior rotation of clavicle

Front 156

Normal kinematic interactions of scapula, humerus, and clavicle for: shoulder extension

Back 156

- extension of humerus
- downward rotation and retraction of scapula
- depression and retraction of clavicle

Front 157

Normal kinematic interactions of scapula, humerus, and clavicle for: shoulder abduction

Back 157

- 2:1 scapulohumeral rhythm of:
-- abduction of humerus
-- upward rotation of scapula
- elevation and posterior rotation of clavicle

Front 158

By what two means can FROM be achieved during shoulder abduction?

Back 158

- ER of shoulder

- performing abduction in scapular plane (about 35 degrees anterior to the frontal plane)--a.k.a. scaption

Front 159

Why is scaption (scapular plane abduction) better for the shoulder than abduction in the true frontal plane?

Back 159

- it is more natural
- it places the greater tuberosity of the humerus under the highest point of the acromion
- the humeral head fits better against the glenoid fossa
- ligaments and muscles (esp. supraspinatus) are more optimally aligned for proper shoulder mechanics

Front 160

What is the static passive locking mechanism of the GH joint?

Back 160

- holds the head of the resting humerus flush against the glenoid fossa

- upper trapezius pulls superiorly to keep scapula in about 5 degrees upward rotation
- superior capsular structure pulls upwardly to counteract gravity

- resultant vector is a compressive force through middle of glenoid fossa

(if scapula rotates downward, SCS line of pull changes, gravity gains an edge, compressive force is lost and humerus slips downward)

Front 161

What group of muscles control the shoulder girdle, and how do they attach?

Back 161

- scapulothoracic

- attach proximally on the axial skeleton; distally to the scapula or clavicle

Front 162

Force-couple for scapular upward rotation

Back 162

- upper trapezius
- lower trapezius
- serratus anterior

Front 163

Force-couple for scapular downward rotation

Back 163

- levator scapulae
- rhomboid major
- pectoralis minor

Front 164

Primary scapular elevators

Back 164

- upper trapezius
- levator scapula
- rhomboids

Front 165

What is optimal scapulothoracic posture

Back 165

slightly retracted and elevated scapulae, with glenoid fossa facing forward

Front 166

What can result from a weak or paralyzed upper trapezius?

Back 166

- depressed and downwardly rotated scapula
- which may lead to superior dislocation of SC joint (lateral end is excessively lowered, leaning on first rib like a fulcrum to pop SC joint)

- may also lead to subluxation of GH joint because static stability is compromised

Front 167

Primary scapular depressors

Back 167

- lower trapezius
- latissimus dorsi
- pectoralis minor
- subclavius

Front 168

Describe the "reverse action" of shoulder depressors.

Back 168

- if they are blocked from depressing the arm/shoulder, they can be used to elevate the trunk

- useful for crutch walking, using a walker, pushing from sit to stand, boosting to transfer to bed or W/C

Front 169

What is the sole scapular protractor?

Back 169

serratus anterior

Front 170

How is scapular winging observed?

How is the serratus anterior strengthened?

Back 170

- during resisted shoulder abduction or during a standard push-up

- by performing a push-up-plus (additional protraction of scapula at end-phase of push-up)

Front 171

Primary scapular downward rotators

Back 171

- rhomboids
- pectoralis minor
- latissimus dorsi may assist

Front 172

Primary scapular retractors

Back 172

- rhomboids
- middle trapezius

Front 173

The sternal head of the ______ is the only GH joint muscle without an attachment to the scapula or clavicle.

Back 173

pectoralis major

Front 174

Primary GH joint abductors

Back 174

- supraspinatus
- middle deltoid
- anterior deltoid
(also requires activation of muscles that upwardly rotate scapula for proper scapulohumeral rhythm)

Front 175

Primary GH joint flexors

Back 175

- anterior deltoid
- coracobrachialis
- pectoralis major (clavicular head)
- biceps brachii
(also requires activation of muscles that upwardly rotate scapula for proper scapulohumeral rhythm)

Front 176

Why is upward rotation of the scapula important with shoulder flexion/abduction?

Back 176

- augments total ROM of shoulder (1/3 of total ROM)
- helps maintain favorable length-tension relationship of GH joint abductors and flexors throughout ROM

Front 177

Primary GH joint adductors

Back 177

- teres major
- latissimus dorsi
- pectoralis major

Front 178

Shoulder extension and adduction require simultaneous....

Back 178

downward rotation of the scapula
(opposite of the upward rotation needed for flexion and abduction)

Front 179

Primary GH joint extensors

Back 179

- latissimus dorsi
- teres major
- posterior deltoid
- pectoralis major
- long head of triceps brachii

Front 180

Horizontal abduction and adduction may be thought of as _____ and ______ turned sideways.

Back 180

- flexion
- extension

(because the shoulder flexors also perform horizontal adduction and the shoulder extensors also perform horizontal abduction)

Front 181

Function of the supraspinatus

Back 181

compresses the humeral head directly into the glenoid fossa

Front 182

Function of the subscapularis, infraspinatus, and teres minor

Back 182

produce an inferiorly directed force on the humerus to counteract the superior translatory force of the deltoid

Front 183

Function of the infraspinatus and teres minor

Back 183

externally rotate humeral head to prevent impingement between greater tuberosity and acromion

Front 184

Primary shoulder internal rotators

Back 184

- teres major
- latissimus dorsi
- pectoralis major
- subscapularis
- anterior deltoid

Front 185

How much more isometric torque can internal rotators produce vs. external rotators? Why?

Back 185

- 1.75 times as much

- they are larger and more numerous than external rotators

Front 186

What may happen due to the imbalance of muscles for shoulder IR vs. ER?

Back 186

- can predispose an individual to poor posture (forward, slouchy shoulders)

- makes weaker ER muscles more prone to injury

Front 187

Primary shoulder ER muscles

Back 187

- teres minor
- infraspinatus
- posterior deltoid

(produces smallest torque of any muscle group at the shoulder)

Front 188

Which muscle group produces the smallest torque of any muscle group at the shoulder?

Back 188

the external rotators

Front 189

Bones in the elbow complex ***

Back 189

- humerus (distal)
- radius (proximal)
- ulna (proximal)

Front 190

Joints in the elbow complex/forearm ***

Back 190

- humero-ulnar
- humero-radial
- superior radio-ulnar
- inferior radio-ulnar

Front 191

Function of superior/inferior radio-ulnar joints ***

Back 191

provide forearm pronation and supination

Front 192

The elbow complex is designed to... ***

Back 192

- provide increased mobility for hand

- provide stability for hand during skilled or forceful activities

Front 193

What are the two articulations of the elbow joint? ***

Back 193

- medially: (humero-ulnar joint) trochlea of humerus articulates with trochlear notch of ulna

- laterally: (humero-radial joint) capitulum of humerus articulates with head of radius

Front 194

What type of joint is the elbow? ***

Back 194

- diarthrodial uniaxial joint
- hinge joint
- one degree of freedom, flexion/extension (sagittal plane)

Front 195

What is the normal ROM of the elbow joint? ***

Back 195

- 135-145 degrees flexion (AROM); up to 5 degrees of hyperextension (or so)

- 150-160 (PROM) because biceps is actively insufficient

Front 196

What is the normal ROM for forearm pronation and supination? ***

Back 196

- 75 degrees of pronation

- 85 degrees of supination

Front 197

What is contained in the elbow joint capsule? ***

Back 197

- humero-ulnar joint
- humero-radial joint
- superior radioulnar joint

Front 198

Purpose of the medial and lateral collateral ligaments of the elbow ***

Back 198

- provide medial (ulnar) and lateral (radial) support to the elbow joint

- offer resistance to distraction stresses

- keep joint surfaces in approximation

Front 199

Which is stronger, the medial collateral ligament (ulnar) or lateral collateral ligament (radial)? ***

Back 199

medial collateral ligament (ulnar) is stronger than the lateral collateral ligament (radial)

Front 200

What is "student's elbow"? ***

Back 200

bursitis caused by leaning on the elbow between the olecranon process and triceps tendon

Front 201

What is "carrying angle"? ***

Back 201

- angulation between the humerus and forearm resulting in abduction of forearm in relation to humerus (due to configuration of joint surfaces)

- obvious in elbow extension

Front 202

What is the typical measurement of the "carrying angle" in males? In females? ***

Back 202

approximately
- 5 degrees in males
- 10-15/18 degrees in females

Front 203

What is it called if the "carrying angle" is greater than the typical norms? ***

Back 203

cubitus valgus

Front 204

What is the "functional arc" of elbow flexion? ***

Back 204

30 to 130 degrees of flexion

(full range is -5 to 145 AROM, to 150-160 PROM)

Front 205

What are the two articulations of the radioulnar joint? ***

Back 205

- proximally: (superior radio-ulnar joint) head of radius with radial notch of ulna

- distally: (inferior radio-ulnar joint) head of ulna with ulnar notch of radius

Front 206

What type of joint is the radioulnar joint? ***

Back 206

- diarthrodial uniaxial joint, pivot joint

- one degree of freedom, pronation/supination of forearm (transverse plane)

Front 207

Describe the motion of the radioulnar joints, radius, and ulna during pronation. ***

Back 207

- radius moves over ulna
- ulna does not rotate

- motion occurs at both superior and inferior radioulnar joints simultaneously

Front 208

What is the functional arc for forearm pronation and supination? ***

Back 208

- a 100-degree arc where the majority of function occurs

- 50 degrees each of pronation and supination

Front 209

Describe the radioulnar joint capsule. ***

Back 209

- encloses the inferior radio-ulnar joint (superior radio-ulnar joint is enclosed in the elbow capsule)

- thick and fibrous
- intra-articular disc
--- articular disc between distal ulna/radius
--- binds distal radius/ulna; increases stability to inferior joint

Front 210

Describe the annular ligament. ***

Back 210

- located at superior radio-ulnar joint
- encircles the rim of the radial head

- retaining contact of head to radial notch of ulna
- lined with articular cartilage

- forms 4/5 osseous ring, other 1/5 formed by radial notch (head of radius articulates on this ring during rotation)

Front 211

Against what does the annular ligament hold the head of the radius? ***

Back 211

against the radial notch of the ulna

Front 212

Name the ligaments of the radioulnar joint ***

Back 212

- anterior radioulnar ligament
- posterior radioulnar ligament
- interosseous membrane

Front 213

Describe the radioulnar interosseous membrane ***

Back 213

- broad collagenous sheet running between ulna and radius
- provides stability for superior and inferior radio-ulnar joints

- provides more surface area for muscle attachments
- provides transmission of forces from hand and/or distal radius and ulna

Front 214

Prime movers of the elbow complex (flexors): ***

Back 214

- biceps brachii
- brachioradialis
- brachialis

Front 215

Which is the strongest of the elbow flexor muscles? ***

Back 215

brachialis

it's a strong flexor regardless of forearm position (pronation or supination) because the insertion is on the ulna

Front 216

Which are stronger, elbow flexors or elbow extensors? ***

Back 216

flexors

Front 217

What is the function of the pronators? ***

Back 217

pull radius medially over ulna into pronation

Front 218

What is the function of the supinators? ***

Back 218

pulls the radius laterally over the ulna out of pronation

Front 219

At what angle is the biceps brachii most effective? ***

Back 219

90 - 100 degrees of flexion

Front 220

Which are stronger, supinator or pronator muscles? ***

Back 220

supinators

Front 221

What is active insufficiency? ***

Back 221

-extreme shortening; over-shortening of agonist
- reduced strength
- active movement

- due to position of muscle as it crosses joints
- inability of a two-joint muscle to exert enough tension to shorten sufficiently to complete FROM in both joints simultaneously

- occurs with biceps during concurrent shoulder flexion/elbow flexion/supination

- occurs with triceps during concurrent shoulder extension/elbow extension

Front 222

What is passive insufficiency? ***

Back 222

- extreme lengthening, caused by overstretching of antagonist
- reduced strength and range of motion
- active movement

- inability of a two-joint muscle to stretch enough to complete FROM in both joints simultaneously

- occurs with biceps during concurrent shoulder/elbow extension/pronation

- occurs with triceps concurrent shoulder/elbow flexion

Front 223

How can passive insufficiency be used to the therapist's/patient's advantage? ***

Back 223

passive insufficiency position for a muscle can be used to stretch a tight muscle

Front 224

What can happen to an elbow immobilized for a prolonged period in 90 degrees flexion? ***

Back 224

significant decrease in flexor strength (decreased sarcomeres) but not in extensor strength

- can affect the ability of flexors to counteract during active elbow extension resulting in hyperextension of elbows

- joint stability diminished due to decreased ability of flexors to produce an effective compression or stabilizing force

Front 225

What is a FOOSH? ***

Back 225

falling on outstretched hand

- excessive longitudinal compressive forces can result in fractures of bony components of elbow complex

- falling on hand with elbow extended (close-packed position with bones already in approximation) – excessive compression forces transmitted through radius and ulna to elbow complex: radial head fx, coronoid/olecranon process fx, distal humerus fx

Front 226

What can occur with excessive longitudinal distraction forces to the arm? ***

Back 226

- can result in stresses on joint ligaments and joint capsule which resist these forces

(e.g., nursemaid’s elbow - yanking or lifting a child by arm puts an excessive distraction force on head of radius and annular ligament; in children, radial head not fully developed and with this distraction force, radial head slips out of annular ligament

Front 227

What can occur with excessive medial or lateral forces to the arm?

Back 227

can cause abnormal stretching of either medial or lateral collateral ligaments, resulting in joint instability and causing abnormal compression forces on contralateral joint surfaces

(e.g., baseball pitching can result in medial joint instability… increased compression forces laterally (articulation with radial head)… avascular necrosis of radial head or fx due to deterioration of hyaline cartilage)

Front 228

What can occur with repetitive force muscle contractions of the arm? ***

Back 228

can result in micro tears or microtrauma damage at musculotendinous junction

(e.g., lateral epicondylitis – frequent injury of athletes who use racquets or paddles in repetitive backhand swing activity; microtrauma to musculotendinous wrist extensor muscles which attach at lateral epicondyle)

Front 229

What are other issues that may occur with elbow/forearm injuries? ***

Back 229

- can affect important neurovascular structures passing through the area, supplying the muscles of the wrist/hand

- if damaged (secondary to fx, dislocation, compression, etc) can affect the functions of wrist/hand

(e.g., brachial artery; ulnar or radial nerve)

Front 230

What muscle functions as a secondary elbow flexor? ***

Back 230

pronator teres

Front 231

Bones of the wrist complex ***

Back 231

- distal radius

- carpals

Front 232

Joints of the wrist complex ***

Back 232

- radiocarpal

- midcarpal

Front 233

Disc of the wrist complex ***

Back 233

radioulnar disc

Front 234

Number of axes/degrees of freedom of wrist complex ***

Back 234

2

- flexion/extension (sagittal plane)
- radial/ulnar deviation (frontal plane)

Front 235

Distal radius and ulna form a concavity that articulates with... ***

Back 235

the convex, proximal row of carpal bones

Front 236

Name the medial and lateral borders of the concavity formed by the distal radius and ulna. ***

Back 236

- ulnar styloid process

- radial styloid process

Front 237

Where is the radial tubercle?
What is its other name? ***

Back 237

- bone projection on dorsal aspect of distal radius

- Lister's tubercle

Front 238

What is the purpose of Lister's tubercle? What is its other name? ***

Back 238

- guides direction of several wrist and thumb extensor muscle tendons

- radial tubercle

Front 239

What are the primary functions of the wrist joint? ***

Back 239

- optimize length-tension relationship of hand muscles whose long tendons pass over the wrist from the forearm to the finger

- permit fine adjustment to grip

Front 240

What bones articulate to form the radiocarpal joint? ***

Back 240

- distal end of radius and radioulnar disc
- scaphoid
- lunate
- triquetrum

(ulna is not part of this joint)

Front 241

Describe the articular (radioulnar) disc of the radiocarpal joint. ***

Back 241

- located at the end of ulna and articulates with lunate and triquetrum

- participates both as part of inferior radioulnar joint and as part of radiocarpal joint

- serves as a shock absorber and a filler for ulna which does not extend as far distally as radius

Front 242

Name the carpal bones of the proximal row. ***

Back 242

- pisiform
- triquetrum
- lunate
- scaphoid

Front 243

Name the carpal bones of the distal row. ***

Back 243

- hamate
- capitate
- trapezoid
- trapezium

Front 244

Which row of carpal bones is loosely jointed? ***

Back 244

- bones within proximal row are loosely joined

- strong ligaments tightly bind distal row

Front 245

Why is the stability of the distal row of carpal bones important? ***

Back 245

distal row stability provides an important rigid base for articulations with metacarpal bones

Front 246

Between what bones is the majority of contact made in the radiocarpal joint? ***

Back 246

- radius
- scaphoid
- lunate

Front 247

Which are the most commonly injured bones in a fall braced with the wrist? ***
(a.k.a. "FOOSH" - fall on outstretched hand)

Back 247

- scaphoid (#1)
- radius
- lunate

Front 248

What type of joint is the radiocarpal joint? ***

Back 248

- synovial
- biaxial
- condyloid (distal radius and disc are concave and articulate with convex scaphoid, lunate, triquetrum)

Front 249

What are the plane, axis, and ROM (degrees) of flexion and extension at the radiocarpal joint? ***

Back 249

- sagittal plane
- medial-lateral axis

- flexion - 85 degrees
- extension - 70-80 degrees

Front 250

What are the plane, axis, and ROM (degrees) of radial and ulnar deviation at the radiocarpal joint? ***

Back 250

- frontal/coronal plane
- anterior-posterior axis

- radial deviation - 20-25 degrees
- ulnar deviation - 30-35 degrees

Front 251

What is the close pack position for the radiocarpal joint? ***

Back 251

extension with slight radial deviation

Front 252

Describe the joint capsule of the radiocarpal joint. ***

Back 252

- strong, but loose capsule

- reinforced by many ligaments (intra/extra-capsular)

Front 253

Describe the ligaments of the radiocarpal joint. ***

Back 253

- multiple ligaments dorsal, volar surfaces, medially and laterally

- serve to reinforce the radiocarpal joint and prevent excessive wrist motions

Front 254

Where is the midcarpal joint? ***

Back 254

- occurs between the two rows of carpals

- articulation between scaphoid, lunate, triquetrum proximally and trapezium, capitate, hamate distally

Front 255

Type of joint, degrees of freedom, and motions allowed for the midcarpal joint ***

Back 255

- synovial, condyloid joint
- 2 degrees of freedom

- small amounts of flexion/extension
- radial and ulnar deviation

Front 256

Describe the capsule and ligaments of the midcarpal joint. ***

Back 256

- capsule is separate from the radiocarpal capsule; encloses all of carpal bones and intercarpal joints

Ligaments
- shares many ligaments with radiocarpal joint
- ligaments reinforce and stabilize the midcarpal joint during wrist actions and offset tendency toward collapse of carpal bones on each other with excessive forces

Front 257

What is the carpal tunnel? ***

Back 257

- partly formed by transverse carpal ligament bridging palmar side of carpal bones

- serves as passageway that helps protect median nerve and tendons of extrinsic flexor muscles of digits

Front 258

What nerve passes through the carpal tunnel? ***

Back 258

median nerve

(the ulnar nerve does not; it passes above the transverse carpal ligament between the pisiform and the hook of the hamate)

Front 259

What tendons pass through the carpal tunnel? ***

Back 259

- flexor digitorum superficialis
- flexor digitorum profundus
- flexor polllicis longus

Front 260

Does the wrist spin in a circular motion about a longitudinal axis? ***

Back 260

not typically

- portions of radiocarpal joint naturally block this twisting motion

- pronation and supination are motions of forearm—not hand or wrist

Front 261

What muscles pronate and supinate the wrist? ***

Back 261

trick question

the wrist does not pronate/supinate, the forearm does; the wrist follows

Front 262

What are the primary functions of the wrist muscles? ***

Back 262

- provide a stable base for the hand

- perform positional adjustments of wrist that allow for optimal length-tension in long finger muscles

Front 263

What is meant by "extrinsic" hand muscles? ***

Back 263

- muscles of hand which originate proximal to wrist

- cross the wrist joint on their way to hand, capable of creating wrist movements

Front 264

Name the primary wrist extensors. ***

Back 264

- extensor carpi radialis longus
- extensor carpi radialis brevis
- extensor carpi ulnaris

Front 265

Name the secondary wrist extensors. ***

Back 265

- extensor pollicis longus
- extensor indicis
- extensor digitorum
- extensor digiti minimi

Front 266

Where is the common proximal attachment for many of the wrist flexors? ***

Back 266

common flexor tendon at the medial epicondyle

Front 267

Where is the common proximal attachment for many of the wrist extensors? ***

Back 267

common extensor tendon at the lateral epicondyle

Front 268

Where are the distal attachments for all wrist muscles? ***

Back 268

- majority are at the metacarpal bases

- some are at the distal carpal row

Front 269

Name the primary wrist flexors. ***

Back 269

- flexor carpi radialis
- palmaris longus
- flexor carpi ulnaris

Front 270

Name the secondary wrist flexors. ***

Back 270

- flexor pollicis longus
- flexor digitorum superficialis
- flexor digitorum profundus

Front 271

Name the primary ulnar deviators of the wrist. ***

Back 271

- flexor carpi ulnaris
- extensor carpi ulnaris

Front 272

Name the secondary ulnar deviators of the wrist. ***

Back 272

trick question

there are none

Front 273

Name the primary radial deviators of the wrist. ***

Back 273

per book:
- extensor carpi radialis longus
- extensor carpi radialis brevis

per her slides:
- extensor carpi radialis longus
- flexor carpi radialis

Front 274

Name the secondary radial deviators of the wrist. ***

Back 274

- flexor carpi radialis
- abductor pollicis longus
- extensor pollicis longus
- extensor pollicis brevis
- flexor pollicis longus

Front 275

Wrist muscles can be classified into: ***

Back 275

- primary set that attaches to wrist or nearby regions

- secondary set that bypasses wrist and attaches more distally to digits

Front 276

All muscles of the wrist cross... ***

Back 276

axes of rotation (medial-lateral and anterior-posterior) located at capitate bone and therefore produce movement at wrist

Front 277

Location of radial nerve in forearm ***

Back 277

courses down posterior aspect of forearm and supplies all muscles that extend wrist

Front 278

Location of medial and ulnar nerves in forearm ***

Back 278

travel down anterior aspect of forearm and innervate all primary wrist flexor muscles

Front 279

What is the role of the wrist extensors during a grasp? ***

Back 279

position and stabilize wrist for activities involving fingers
(e.g., making strong fist or grasp)

- contraction of wrist extensors is necessary to prevent wrist from “collapsing” into flexion because of strong flexion pull of extrinsic finger flexor muscles

- therefore, wrist extensor muscles must contract every time a grasp is made; if not, wrist collapses into unwanted flexion

Front 280

What can result from a FOOSH? ***

Back 280

catching falls on outstretched hand and wrist in extension (close-packed position) can result in:

- fracture of distal radius (Colles’ fracture)
- fractures/dislocations of scaphoid or lunate due to ligamentous instability
- may lead to avascular necrosis, as the blood supply to the lunate and scaphoid is poor

Front 281

Most often, wrist muscles are responsible for... ***

Back 281

positioning the hand

Front 282

Which of the following statements is true regarding the interosseous membrane? ***

a. it helps bind the radius and ulna together for increased stability
b. it helps transmit compression forces from the hand or wrist evenly through the humeroulnar and humeroradial joints of the elbow
c. it helps bind the radius to the humerus for increased valgus stability
d. a and b
e. b and c

Back 282

d. a and b

Front 283

Which of the following muscles becomes maximally stretched in full supination of the forearm and full elbow extension? ***
a. supinator
b. long head of the triceps
c. pronator teres
d. lateral head of the triceps
e. a and b

Back 283

c. pronator teres

Front 284

Injury to the radial nerve will likely result in significant weakness of which action? ***

a. elbow flexion
b. elbow extension
c. wrist flexion
d. shoulder flexion
e. all of the above

Back 284

b. elbow extension

Front 285

How many degrees of freedom are allowed at the humeroulnar joint? ***

a. 1
b. 2
c. 3
d. 4

Back 285

a. 1

Front 286

Beginning with the forearm in a fully pronated position and the elbow flexed to 90 degrees, which of the following muscles can supinate the forearm? ***

a. brachialis
b. brachioradialis
c. biceps brachii
d. a and c
e. b and c

Back 286

e. b and c (brachialis attaches to ulna, no pronation/supination effects)

Front 287

Which of the following statements is true? ***

a. full range of motion of elbow flexion is typically 100 degrees
b. normal cubitus valgus (of the elbow) is approximately 15 degrees
c. the brachioradialis is innervated by the musculocutaneous nerve
d. a bony end feel at the elbow is usually associated with full elbow flexion

Back 287

b. normal cubitus valgus (of the elbow) is approximately 15 degrees

Front 288

Which of the following statements is true? ***

a. with the hand free, supination and pronation of the forearm result from the radius rotating about the ulna
b. when pushing down on the hand, most of the compressive force is transmitted directly to the ulna, not the radius
c. the pronator quadratus attaches to the distal humerus
d. the long head of the triceps is an effective pronator of the forearm
e. b and d

Back 288

a. with the hand free, supination and pronation of the forearm result from the radius rotating about the ulna

Front 289

Which of the following muscles has its distal attachment on the radius? ***

a. brachialis
b. brachioradialis
c. biceps brachii
d. a and b
e. b and c

Back 289

e. b and c

Front 290

Which of the following muscles is innervated by the radial nerve? ***

a. brachialis
b. brachioradialis
c. medial head of the triceps
d. a and b
e. b and c

Back 290

e. b and c

Front 291

Which of the following positions maximally elongates the long head of the triceps? ***

a. shoulder flexion and elbow extension
b. shoulder flexion and elbow flexion
c. shoulder extension and elbow extension
d. shoulder extension and elbow flexion

Back 291

b. shoulder flexion and elbow flexion

Front 292

Which of the following statements is true regarding the interosseous membrane? ***

a. it helps bind the radius and ulna together for increased stability
b. it helps transmit compression forces from the hand or wrist evenly through the humeroulnar and humeroradial joints of the elbow
c. it helps bind the radius to the humerus for increased valgus stability
d. a and b
e. b and c

Back 292

d. a and b

Front 293

Which of the following muscles becomes maximally stretched in full supination of the forearm and full elbow extension? ***
a. supinator
b. long head of the triceps
c. pronator teres
d. lateral head of the triceps
e. a and b

Back 293

c. pronator teres

Front 294

Injury to the radial nerve will likely result in significant weakness of which action? ***

a. elbow flexion
b. elbow extension
c. wrist flexion
d. shoulder flexion
e. all of the above

Back 294

b. elbow extension

Front 295

How many degrees of freedom are allowed at the humeroulnar joint? ***

a. 1
b. 2
c. 3
d. 4

Back 295

a. 1

Front 296

Beginning with the forearm in a fully pronated position and the elbow flexed to 90 degrees, which of the following muscles can supinate the forearm? ***

a. brachialis
b. brachioradialis
c. biceps brachii
d. a and c
e. b and c

Back 296

e. b and c

Front 297

Which of the following statements is true? ***

a. full range of motion of elbow flexion is typically 100 degrees
b. normal cubitus valgus (of the elbow) is approximately 15 degrees
c. the brachioradialis is innervated by the musculocutaneous nerve
d. a bony end feel at the elbow is usually associated with full elbow flexion

Back 297

b. normal cubitus valgus (of the elbow) is approximately 15 degrees

Front 298

Which of the following statements is true? ***

a. with the hand free, supination and pronation of the forearm result from the radius rotating about the ulna
b. when pushing down on the hand, most of the compressive force is transmitted directly to the ulna, not the radius
c. the pronator quadratus attaches to the distal humerus
d. the long head of the triceps is an effective pronator of the forearm
e. b and d

Back 298

a. with the hand free, supination and pronation of the forearm result from the radius rotating about the ulna

Front 299

Which of the following muscles has its distal attachment on the radius? ***

a. brachialis
b. brachioradialis
c. biceps brachii
d. a and b
e. b and c

Back 299

e. b and c

Front 300

Which of the following muscles is innervated by the radial nerve? ***

a. brachialis
b. brachioradialis
c. medial head of the triceps
d. a and b
e. b and c

Back 300

e. b and c

Front 301

Which of the follwing positions maximally elongates the long head of the triceps? ***

a. shoulder flexion and elbow extension
b. shoulder flexion and elbow flexion
c. shoulder extension and elbow extension
d. shoulder extension and elbow flexion

Back 301

b. shoulder flexion and elbow flexion

Front 302

The trochlea is a structure on which bone? ***

a. humerus
b. radius
c. ulna
d. scapula

Back 302

a. humerus

Front 303

The primary function of the annular ligament is to: ***

a. help transmit forces from the ulna to the humerus
b. bind the radial head to the proximal ulna
c. bind the distal radius to the distal ulna
d. serve as an attachment for the triceps

Back 303

b. bind the radial head to the proximal ulna

Front 304

For a low-effort elbow extension activity, the nervous system will first "choose" the medial and lateral heads of the triceps over the long head of the triceps because: ***

a. the medial and lateral heads also perform shoulder flexion
b. the medial and lateral heads also perform shoulder extension
c. activation of the long head requires simultaneous activation of the anterior deltoid to prevent unwanted shoulder extension
d. the long head of the triceps has a poor line of pull to perform elbow extension

Back 304

c. activation of the long head requires simultaneous activation of the anterior deltoid to prevent unwanted shoulder extension

Front 305

In the anatomic position: ***

a. the radius is medial to the ulna
b. the forearm is pronated
c. the radius is lateral to the ulna
d. the trochlea is lateral to the capitulum

Back 305

c. the radius is lateral to the ulna

Front 306

During strong activation of the biceps to perform elbow flexion, the posterior head of the deltoid must be activated to prevent: ***

a. unwanted supination of the forearm
b. unwanted flexion of the shoulder
c. excessive cubitus valgus
d. excessive cubitus varus

Back 306

b. unwanted flexion of the shoulder

Front 307

A Colles' fracture refers to: ***

a. an impaction fracture of the humeral head
b. simultaneous fracture of the proximal radius and ulna
c. a fracture of the distal radius
d. a rupture of the interosseous membrane

Back 307

c. a fracture of the distal radius

Front 308

Performing elbow extension with the shoulder in an extended position: ***

a. requires activation of the brachialis
b. produces automatic pronation of the forearm
c. results in the long head of the triceps becoming actively insufficient
d. is the strongest position for producing elbow extension torque

Back 308

c. results in the long head of the triceps becoming actively insufficient

Front 309

Individuals with a painful or inflamed elbow: ***

a. typically hold the elbow in a fully extended position to maximally stabilize the surrounding musculature
b. typically hold the elbow in 70-90 degrees of flexion to help reduce intracapsular pressure and therefore be in a position of comfort
c. are typically unable to extend the shoulder past neutral
d. are typically compensating for weakness of the opposite shoulder

Back 309

b. typically hold the elbow in 70-90 degrees of flexion to help reduce intracapsular pressure and therefore be in a position of comfort

Front 310

Injury to the musculocutaneous nerve will most likely result in: ***

a. elbow extensor weakness
b. elbow flexor weakness
c. pronator weakness
d. shoulder extensor weakness

Back 310

b. elbow flexor weakness

Front 311

A cubitus valgus-producing force is most likely to injure the: ***

a. medial collateral ligament of the elbow
b. long head of the biceps
c. long head of the triceps
d. lateral collateral ligament of the elbow

Back 311

a. medial collateral ligament of the elbow

Front 312

The biceps brachii and the brachialis are both innervated by the musculocutaneous nerve. ***

a. true
b. false

Back 312

a. true

Front 313

The brachialis is an effective supinator of the forearm. ***

a. true
b. false

Back 313

b. false (the brachialis does not pronate or supinate at all because it attaches distally to the ulna; all it does is elbow flexion--for which it is the body's "workhorse")

Front 314

The end feel for elbow extension is typically considered bony. ***

a. true
b. false

Back 314

a. true

Front 315

Excessive valgus-producing force to the elbow will likely result in injury to the lateral collateral ligament of the elbow. ***

a. true
b. false

Back 315

b. false (excessive valgus producing force will most likely injure the medial collateral ligament of the elbow; valgus will stretch the inside/medial aspect and slacken the outside/lateral aspect of the elbow joint

Front 316

Compressive force through the radius is transferred to the ulna largely by the interosseous membrane. ***

a. true
b. false

Back 316

a. true

Front 317

The lateral head of the triceps courses anterior to the medial-lateral axis of rotation of the elbow. ***

a. true
b. false

Back 317

b. false (it courses posterior to the medial-lateral axis of the elbow)

Front 318

The first muscle to be chosen for a low effort-level elbow flexion activity is most likely the biceps brachii because it is a multiarticular muscle. ***

a. true
b. false

Back 318

b. false (the muscle most likely to be recruited for low effort-level elbow flexion is the brachialis, the "workhorse" of elbow flexion; that is all it does, and it won't require activation of additional muscles to suppress other actions)

Front 319

Along with binding the radius and ulna together, the interosseous membrane serves as the site of attachment for many muscles. ***

a. true
b. false

Back 319

a. true

- flexor digitorum superficialis
- extensor indicis
- flexor pollicis longus
- extensor pollicis longus
- extensor pollicis brevis
- abductor pollicis longus

Front 320

In a pronated position of the forearm, the radius is crossed over the top of the ulna. ***

a. true
b. false

Back 320

a. true

Front 321

The three primary actions of the biceps brachii are supination, elbow flexion, and shoulder flexion. ***

a. true
b. false

Back 321

a. true

Front 322

Articulations of the elbow

Back 322

- humeroulnar joint

- humeroradial joint

Front 323

Articulations of the forearm

Back 323

- proximal radioulnar joint

- distal radioulnar joint

Front 324

Four bones that relate to the function of the elbow and forearm complex

Back 324

- scapula
- distal humerus
- radius
- ulna

Front 325

What bony features of the scapula are important to the muscles of the elbow?

Back 325

- coracoid process
- supraglenoid tubercle
- infraglenoid tubercle

Front 326

What is the trochlea?

Back 326

- a spool-shaped structure on the medial side of distal humerus

- articulates with ulna to form humeroulnar joint

Front 327

What is the coronoid fossa of the distal humerus?

Back 327

a pit just superior to the trochlea that accepts the coronoid process of the ulna when elbow is fully flexed

Front 328

What is the capitulum?

Back 328

- rounded area lateral to the trochlea

- articulates with the head of the radius to form the humeroradial joint

Front 329

What structures attach to the medial epicondyle?

Back 329

medial epicondyle is the proximal attachment for:

- most of the wrist flexors
- pronator teres
- medial collateral ligament

Hint 329

Your LES comes from MPF
lateral - extensors and supinator
medial - pronators and flexors

Front 330

What structures attach to the lateral epicondyle?

Back 330

lateral epicondyle is the proximal attachment for:

- most of the wrist extensors
- supinator
- lateral collateral ligament

Hint 330

Your LES comes from MPF
lateral - extensors and supinator
medial - pronators and flexors

Front 331

The rough posterior surface of the olecranon process of the ulna is the distal attachment for:

Back 331

the triceps muscles

Front 332

In a fully supinated position, the radius lies _____ and
______ to the ulna.

Back 332

parallel and lateral to the ulna

Front 333

In which direction is the head of the radius? Head of the ulna?

Back 333

- proximal

- distal

Front 334

Fovea

Back 334

shallow, cup-shaped depression on the head of the radius that articulates with the head of the humerus

Front 335

Radial (bicipital) tuberosity

Back 335

- enlarged ridge on anterior-medial aspect of proximal radius

- primary distal attachment for biceps brachii

Front 336

Ulnar notch

Back 336

small depression on the medial side of the distal radius that articulates with the ulnar head, forming the distal radioulnar joint

Front 337

Which joint provides most of the structural stability to the elbow as a whole?

Back 337

humeroulnar

Front 338

Describe the movement of the humeroradial joint during
- pronation/supination
- flexion/extension

Back 338

- radius (at fovea) spins on its own axis at the capitulum of the humerus

- (concave) radial head rolls and slides over rounded (convex) capitulum--same direction

Front 339

Normal cubitus valgus in degrees

Back 339

15-20 degrees (18 degrees)

Front 340

Another term for normal cubitus valgus

Back 340

carrying angle

Front 341

What is cubitus varus?

Back 341

when the forearm does not project laterally 15-20 degrees when supinated and fully extended

Front 342

Describe the articular capsule of the elbow joint.

Back 342

connective tissue enclosing
- humeroulnar joint
- humeroradial joint
- proximal radioulnar joint

Front 343

How does the medial collateral ligament provide stability to the elbow?

Back 343

primarily by resisting cubitus valgus-producing forces

Front 344

How does the lateral collateral ligament of the elbow provide stability?

Back 344

primarily by resisting cubitus varus-producing forces

Front 345

Normal ROM for elbow flexion/extension

Back 345

- 5 degrees hyperextension to
145 degrees of flexion

Front 346

What is the normal arc of motion for elbow flexion/extension in typical activities of daily living?

Back 346

a 100-degree arc of
30-130 degrees of flexion

Front 347

What limits excessive elbow extension?

Back 347

bony articulation of the olecranon process in the olecranon fossa

Front 348

What is "end feel"?

Back 348

the feel of a joint as it reaches maximum ROM

Front 349

Joints of the forearm

Back 349

- proximal radioulnar joint

- distal radioulnar joint

Front 350

Motion of the radioulnar joints

Back 350

- pronation

- supination

Front 351

Pronation and supination involve the radius rotating around....

Back 351

a relatively fixed ulna

Front 352

Where does pronation and supination take place, at the hand or forearm?

Back 352

forearm, the hand just comes along for the ride

Front 353

Annular ligament

Back 353

- thick, circular band of connective tissue that wraps around the radial head and attaches to either side of the radial notch of the ulna

- holds radial head firmly against ulna, allowing it to spin freely during supination and pronation

Front 354

Distal radioulnar joint capsule

Back 354

- stabilizes the joint

- reinforced by palmar and dorsal capsular ligaments

Front 355

Interosseous membrane

Back 355

- binds radius to ulna
- enables transmission of forces from radius to ulna
- muscular attachment site

Front 356

What is the 0 degree (neutral) position of the forearm?

Back 356

thumb up

Front 357

From position of a neutral forearm, approximately how much pronation and supination is possible?

Back 357

- 75 degrees pronation

- 85 degrees supination

Front 358

How do individuals lacking full ROM for pronation and/or supination compensate?

Back 358

by internally and externally rotating the shoulder

Front 359

What do IR, ER, pronation, and supination combine to enable?

Back 359

the hand to rotate nearly 360 degrees in space

Hint 359

PIR

SER

Front 360

How are IR and ER eliminated from muscle testing of supination and pronation?

Back 360

flex the elbow to 90 degrees

Front 361

Restricted ROM at either the proximal or distal radioulnar joint will....

Back 361

limit the motion at the other

motions creating pronation and supination occur at both joints simultaneously

Front 362

What is "pulled elbow" syndrome?

Back 362

when the radius is forcefully pulled from the annular ligament by a sharp pull at the wrist or radius

Front 363

Why does "pulled elbow" happen most often to small children?

Back 363

- ligamentous laxity
- undeveloped musculature
- likelihood of others pulling on their arms (dressing, hand holding, etc.)

Front 364

Arthrokinematics of pronation and supination (3 facts)

Back 364

- only the radius moves; ulna stays essentially stationary
- radial head spins in place in direction of moving thumb
- distal radius rolls and slides in the same direction relative to ulnar head (concave on convex)

Front 365

Why is a pronated forearm in a position of relative stability?

Back 365

- radius and wrist are braced against ulna

- ulna is firmly anchored to humerus

Front 366

Which joint is the "shared joint" or the functional link between the elbow and forearm?

Back 366

humeroradial joint

Front 367

Which forearm bone absorbs more compressive force?

Back 367

radius

Front 368

How does the interosseous membrane help transfer compressive forces?

Back 368

- a compressive force absorbed by the radius will stretch the interosseous membrane

- the stretched membrane transfers some of the compressive force to the ulna

- this enables force to be shared more equally through the humeroulnar and humeroradial joints

Front 369

How are the fibers of the interosseous membrane oriented?

Back 369

- obliquely (distally and medially from the radius)

Front 370

How much of a compressive force is typically transmitted through the radius at the radiocarpal joint?

Back 370

80 percent

Front 371

What elbow/forearm muscles are supplied by the musculocutaneous nerve?

Back 371

most of the elbow flexors
- biceps brachii
- brachialis
- coracobrachialis

(except
brachioradialis - radial and
pronator teres - median)

Front 372

What elbow/forearm muscles are supplied by the radial nerve?

Back 372

most of the extensors of the elbow, forearm, wrist, and digits
- triceps brachii
- brachioradialis

- supinator
- anconeus

- extensor carpi radialis longus
- extensor carpi radialis brevis
- extensor carpi ulnaris

- extensor pollicis longus
- extensor pollicis brevis
- abductor pollicis longus

- extensor indicis
- extensor digitorum
- extensor digiti minimi

Front 373

What elbow/forearm/wrist muscles are supplied by the median nerve?

Back 373

all the pronators of the forearm, most wrist flexors, extrinsic (long) flexors of the digits (except FDP to ring and little finger) most intrinsic muscles of thumb (muscles of the thenar eminence), and two lateral lumbricals

- pronator teres
- pronator quadratus

- flexor carpi radialis
- flexor digitorum superficialis
- flexor digitorum profundus
- palmaris longus

- opponens pollicis
- abductor pollicis brevis
- flexor pollicis longus (brevis)

- lateral lumbricals

Front 374

What is unique about the elbow flexors? Why is this likely the case?

Back 374

- they are innervated by three separate nerves

- possibly is evolutionary protective mechanism because feeding/hand-to-mouth activity is so important; it is unlikely that all three nerves will be completely damaged

Front 375

Prime movers of elbow flexion

Secondary

Back 375

primary
- biceps brachii
- brachialis
- brachioradialis

secondary
- pronator teres

Front 376

Any elbow flexor that attaches distally to the radius will also ______ the forearm.

Back 376

pronate or supinate
- pronator teres
- biceps brachii
- brachioradialis
(brachialis attaches to the ulna, so is not affected in its line of pull by pronation or supination)

Front 377

The combined action of elbow flexion and forearm supination provided by the _____ muscle is important in bringing the palm of the hand toward the face such as when eating.

Back 377

biceps brachii

Front 378

Which muscle is the "workhorse" of elbow flexion? Why is it so effective?

Back 378

brachialis

it attaches distally to the ulna, thus pronation/supination of the forearm has no influence on its length or force-producing capability;

also, it only does elbow flexion so no other stabilizing muscles are needed to prevent unwanted forearm motion

thus it is the muscle of choice by the nervous system for elbow flexion

Front 379

What actions does contraction of the brachioradialis cause?
What is the effect on torque production?

Back 379

- elbow flexion and rotation to the neutral (thumb up) forearm position

- this enhances the flexion leverage and amplifies torque production

Front 380

What generally happens to muscles without a functional antagonist?

(e.g., C5/C6 quadriplegia w/functioning biceps but no triceps function)

Back 380

the muscle is at risk of developing a contracture, becoming over-shortened and tight

Front 381

When a muscle becomes tight, over-shortened, or contracted it will create a posture....

Back 381

that reflects all of its potential actions

(e.g., C5/C6 quadriplegia w/functioning biceps but no triceps function; arm will reflect shoulder and elbow flexion and forearm supination)

Front 382

To maximally stretch a muscle, it must be placed in a position....

Back 382

opposite to all of its actions

(e.g., C5/C6 quadriplegia w/functioning biceps but no triceps function, arm should be placed in shoulder and elbow extension and forearm pronation)

Front 383

As the "workhorse" of elbow flexion, the brachialis does most of the work, but if the load requires recruitment of the biceps brachii as well, what other adjustments must the body make?

Back 383

since the biceps is also shoulder flexor, a shoulder extensor muscle (like the posterior deltoid) must be activated to counter the unwanted shoulder flexion

Front 384

How is a multiarticular muscle forced into expressing only one action?

Back 384

the muscle will naturally try to express all its actions during contraction, but by recruitment of opposing muscles the unwanted action is cancelled or offset

Front 385

What is a stabilizer?

What can weakness in a stabilizer muscle cause?

Back 385

- a muscle that cancels a given action of another muscle (e.g., posterior deltoid cancels the unwanted shoulder flexion of the biceps brachii during elbow flexion)

- the unwanted action of a multiarticular muscle is insufficiently suppressed

Front 386

How is the optimal length-tension relationship expressed in the biceps brachii during a pulling motion?

Back 386

- elbow flexion is combined with shoulder extension

- muscle shortens across the elbow as it lengthens across the shoulder

- by contracting at one end and lengthening at the other, it only shortens a small net distance and maintains an optimal length-tension relationship (actively efficient)

Front 387

When is a muscle considered actively efficient?

Back 387

when a given effort level produces a greater force

- during muscle contraction, the muscle fibers shorten a relatively small amount per instant in time, and

- muscle remains at nearly optimal length (to create contractile force) throughout an active movement

in the biceps brachii pulling example, the shoulder extensors are offsetting the biceps tendency to shoulder flexion, thus all torque created by the biceps is focused solely on elbow flexion and forearm supination

Front 388

How may the elbow flexors be used in a closed chain?

Back 388

- by anchoring the wrist, the elbow flexors can be used to bring the humerus toward the forearm

- this reverse action would enable a person with C6 quadriplegia to pull to a sitting position

(they have shoulder flexors, but paralysis of triceps or trunk musculature to push up)

Front 389

Primary elbow extensors

Back 389

- triceps brachii (all three heads)
- anconeus

Front 390

Because elbow extension is often associated with pushing motions, the elbow extensor muscles often work in concert with ______ to achieve the desired action.

Back 390

shoulder flexor muscles

Front 391

Pull = _______ + ________

Back 391

elbow flexors + shoulder extensors

- biceps brachii
- brachialis
- brachioradialis
- pronator teres

+

- posterior deltoid
- latissimus dorsi
- teres major
- pectoralis major
- LH of triceps brachii

Front 392

Push = ______ + ________

Back 392

elbow extensors + shoulder flexors

- triceps brachii
- anconeus

+

- anterior deltoid
- coracobrachialis
- pectoralis major (clavicular head)
- biceps brachii

Front 393

Which heads of the triceps brachii extend the elbow? Extend the shoulder?

Back 393

- all heads

- long head only

Front 394

How is the triceps brachii generally activated to produce a large force? A smaller force

Back 394

- all three heads

- only the medial and lateral (one-joint) heads, since activation of the long head would likely extend the shoulder and more muscles would have to be recruited to offset this (metabolically inefficient)

Front 395

How may shoulder muscles be used to substitute for triceps paralysis in patients with C6 and above quadriplegia?

Back 395

since they cannot push away with the elbow extensors (negatively impacting independent transfer), they can

- use muscle substitution, such as the shoulder muscles (pectoralis major and anterior deltoid) to extend and lock the elbow on a firmly fixed hand, contracting the shoulder muscles to adduct or horizontally adduct the GH joint

- this pulls the humerus toward midline, and since the hand is fixed, the forearm must follow and the elbow is pulled into extension

- once elbow is extended, arm can be used as a stable base for transfer

Front 396

Why does muscle activity in persons with a brain injury or other disease affecting motor planning appear labored or uncoordinated?

Back 396

- because the nervous system normally selects just the right muscles for the given task

- persons with the mentioned conditions may activate more muscles than necessary for the task, thus appearing labored or uncoordinated

Front 397

What common activity requires strong activation from all three heads of the triceps brachii?

Back 397

pushing

Front 398

In a pushing motion, how can the shoulder flex when the long head of the triceps brachii (a shoulder extensor) is active?

Back 398

the shoulder flexors (e.g., anterior deltoid) overpower the extension tendency of the long head of the triceps brachii, and all the triceps' contractile energy is channeled into elbow extension torque

Front 399

What are the two requirements for muscles that pronate or supinate the forearm?

Back 399

- muscles must originate on the humerus, ulna, or both AND insert on the radius or hand

- must have a line of force that intersects (vice parallels) the axis of rotation of the forearm joints

(line of pull in the horizontal plane that tracks either anterior/posterior or clockwise/counterclockwise and perpendicular to longitudinal axis)

Front 400

What happens to a multiarticular muscle if it expresses all its actions at once?

Back 400

it becomes too short or

actively insufficient

Front 401

Primary supinator muscles?

Secondary supinators?

Back 401

- supinator
- biceps brachii

- extensor indicis
- extensor pollicis longus
(and brachioradialis can supinate or pronate to neutral position)

Front 402

Function of the supinator

Back 402

- from forearm pronated position, the supinator wraps over the top of the radius, giving it the ability to spin the radius back into supination

- first muscle to respond to task requiring low level of supination force; biceps brachii assists if more force is needed

Front 403

Effectiveness of the biceps as a supinator is greatest when....

Back 403

the elbow is flexed to near 90 degrees, because the biceps tendon approaches the radius at a 90-degree angle

Front 404

What is the reasoning behind, "righty-tighty"?

Back 404

- greater force is required to tighten a screw than to loosen it

- supinator muscles as a group are stronger than pronator muscles

Front 405

How is the triceps involved in supination?

Back 405

- triceps must neutralize tendency of the biceps to flex the elbow

- because the triceps attaches to the ulna, it stabilizes the humeroulnar joint, but does not interfere with the mechanics of a supination task

Front 406

Primary pronator muscles?

Secondary pronator muscles?

Back 406

- pronator teres
- pronator quadratus

- flexor carpi radialis
- palmaris longus

Front 407

Why is the pronator quadratus a particularly effective pronator?

Back 407

because it intersects the axis of rotation at the forearm at a near-perfect right angle

Front 408

When does the pronator teres assist the pronator quadratus?

Back 408

- when larger pronation forces are required

- when elbow flexion is also desired (the elbow will flex when pronator teres is activated, unless neutralized by the triceps)

Front 409

Describe the supinator-biceps and pronator quadratus-pronator teres functional relationships

Back 409

- a small, one-joint muscle handles lower-force supination and pronation (supinator, pronator quadratus)

- if more force/torque is needed a two-joint muscle is available to augment the movement (biceps, pronator teres)

Front 410

Muscles must stabilize the elbow and forearm complex to allow for....

Back 410

transmission of external forces between the hand and shoulder

Front 411

In addition to stability, the elbow and forearm complex must supply ample mobility to...

Back 411

- adjust the functional length of the arm (flexing/extending elbow), and

- place the hand in a position of function (supinating/pronating forearm)

Front 412

How many carpals comprise the wrist?

Back 412

8

Front 413

What are the two major articulations of the wrist?

Back 413

- radiocarpal joint

- midcarpal joint

Front 414

What is the function of the radial tubercle (Lister's tubercle)?

Back 414

to help guide the direction of the tendons of several wrist and thumb extensor muscles

Front 415

Which row of carpal bones is tightly bound by strong ligaments?

Back 415

distal row

(proximal row is loosely joined)

Front 416

The stability of the distal row of carpals provides....

Back 416

a rigid base for articulations with metacarpal bones

Front 417

What is the most-fractured carpal bone? Why?

Back 417

- scaphoid

- it lies in the direct pathway of the forces that cross the wrist

Front 418

Why is healing of a scaphoid or lunate fracture/injury frequently hindered?

Back 418

because blood supply to the fractured bone is often poor

Front 419

What muscles/ligaments attach to the lunate? What does this cause

Back 419

- no muscles
- few ligaments

loose articulation and makes it the most frequently dislocated carpal bone

Front 420

What type of bone is the pisiform?

Back 420

it is a sesamoid bone of the flexor carpi ulnaris tendon, not a true carpal

Front 421

What joint is the trapezium a part of? What is the result of this?

Back 421

- the first carpometacarpal joint (thumb)

- a specialized articulation that allows a wide ROM of the thumb

Front 422

Function of the trapezoid carpal bone

Back 422

stable base for the second metacarpal

Front 423

Description of the capitate

Back 423

- largest carpal bone
- centrally located
- axis of rotation for all wrist motion passes through it

Front 424

Description of the hamate

Back 424

has a prominent hook-like process on its palmar surface

Front 425

What ligament creates the carpal tunnel?

Back 425

transverse carpal ligament, which bridges the carpal bones on the palmar side

Front 426

The carpal tunnel protects:

Back 426

- median nerve

- extrinsic flexor muscles
(flexor digitorum superficialis
flexor digitorum profundus
flexor pollicis longus)

Front 427

What causes carpal tunnel syndrome?

Back 427

prolonged and/or extreme wrist positions irritate tendons and synovial sheaths (FDS, FDP, etc.), which swell within the tightly packed carpal tunnel space and press on the median nerve

this causes pain, paresthesia (tingling) or both over the sensory distribution of the median nerve; in extreme cases, muscular weakness and atrophy may occur in the intrinsic muscles around the thumb

Front 428

What carpals are connected by the transverse carpal ligament?

Back 428

- pisiform

- trapezium & scaphoid

Front 429

Does the ulnar nerve pass through the carpal tunnel?

Back 429

no, it passes over the transverse carpal ligament

Front 430

Describe the radiocarpal joint

Back 430

proximal
- concave surface of radius
- adjacent articular disc

distal
- convex articular surfaces of scaphoid and lunate

Front 431

Approximately 80% of force that crosses the wrist passes between....

Back 431

- the scaphoid/lunate and

- radius

Front 432

Why are the distal ulna and ulnar-sided carpal bones less likely to fracture?

Back 432

- they are not in the direct path of weight bearing

- a relatively wide space exists between the distal ulna and ulnar carpal bones (ulnocarpal space)

Front 433

What is the most prominent midcarpal joint articulation?

Back 433

articulation between head of the capitate and socket formed by the distal surfaces of the scaphoid and lunate

Front 434

The joints of the wrist are enclosed within a fibrous capsule, which is thickened by...

Back 434

extrinsic and intrinsic ligaments

Front 435

Differentiate between extrinsic and intrinsic ligaments

Back 435

- extrinsic ligaments have proximal attachments outside the carpal bones, but distally attach within the carpal bones

- intrinsic ligaments have both proximal and distal attachments within the carpal bones

Front 436

What are the four primary extrinsic ligaments?

Back 436

- radial collateral ligament
- ulnar collateral ligament

- dorsal radiocarpal ligament
- palmar radiocarpal ligament

Front 437

Function of the intrinsic carpal ligaments

Back 437

- interconnect carpal bones
- help transfer forces between the hand and forearm
- maintain the natural shapes of radiocarpal and midcarpal joints to minimize joint stress during movement

Front 438

What is another name for the ulnocarpal complex, and what structures comprise it?

Back 438

triangular fibrocartilage complex (TFCC)

- articular disc
- ulnar collateral ligament
- palmar ulnocarpal ligament

Front 439

Description of dorsal radiocarpal ligament

Back 439

- resists extremes of wrist flexion

- attaches between radius and dorsal side of carpal bones

Front 440

Description of radial collateral ligament

Back 440

- resists extremes of ulnar deviation

- strengthened by abductor pollicis longus and extensor pollicis brevis

- attaches between distal radius and lateral carpal bones

Front 441

Description of palmar radiocarpal ligament

Back 441

- resists extremes of wrist extension

- thickest ligament of wrist, consists of three parts:
--- radiocapitate
--- radiolunate
--- radioscapholunate

Front 442

Description of ulnar collateral ligament

Back 442

- resists extremes of radial deviation

- part of the ulnocarpal complex (TFCC), comprising
--- articular disc
--- ulnar collateral ligament
--- palmar ulnocarpal ligament

Front 443

What is prone to happen to the loosely articulated proximal carpals when compressed strongly from both ends of an unstable wrist?

Back 443

collapse in a zigzag fashion, like a train derailing

Front 444

Does the wrist spin during pronation/supination?

Back 444

no, the forearm rotates and the hand follows the radius

Front 445

The medial-lateral and anterior-posterior axes of rotation at the wrist pass through....

Back 445

the head of the capitate

Front 446

ROM at the wrist for:
- flexion
- extension
- total

Back 446

- 70-80 degrees
- 60-65 degrees
- 130-145 degrees

Front 447

Total wrist flexion normally exceeds total wrist extension by about....

Back 447

15 degrees

Front 448

Wrist extension is normally limited by....

Back 448

- tension in the thicker palmar radiocarpal ligaments

- the carpal bones contacting the slightly elongated dorsal side of the distal radius

Front 449

Normal ROM for
- ulnar deviation
- radial deviation
- total deviation at the wrist

Back 449

- 30-35 degrees ulnar
- 15-20 degrees radial
- 45-55 degrees total

Front 450

Maximum ulnar deviation is normally ____ that of radial deviation. Why?

Back 450

twice

primarily because of the void created by the ulnocarpal space (radial deviation is blocked by contact between the styloid process of the radius and radial side of the carpal bones

Front 451

For activities of daily living, about how much sagittal plane and frontal/coronal plane motion is required at the wrist?

Back 451

sagittal
- 45 degrees total
- 5-10 degrees flexion
- 30-35 degrees extension

frontal/coronal
- 25 degrees total
- 15 degrees ulnar deviation
- 10 degrees radial deviation

Front 452

If a severely painful or unstable wrist must be fused, how will it likely be positioned?

Back 452

in an average position of function
- 10-15 degrees extension
- 10 degrees ulnar deviation

Front 453

What is the central column of the wrist?

Back 453

- radius
- lunate
- capitate
- third metacarpal

Front 454

Wrist movement occurs simultaneously at the _____ and ______ joints

Back 454

- radiocarpal

- midcarpal

Front 455

Arthrokinematics of wrist extension/flexion and ulnar/radial deviation at the central column

Back 455

- movement at both radiocarpal and midcarpal joints

- all are convex-on-concave rotations, thus roll and slide at both joints for all four motions is in opposite directions

Front 456

The radial nerve travels down the _____ aspect of the forearm and innervates all the muscles that ________

Back 456

- posterior

- extend the wrist

Front 457

The median and ulnar nerves travel down the _____ aspect of the forearm and innervate all the primary _______

Back 457

- anterior

- wrist flexor muscles

Front 458

What are the two categories of wrist muscles?

Back 458

- the primary set that attaches to the wrist or nearby regions

- the secondary set that bypasses the wrist and attaches more distally to the digits

Front 459

What are the extrinsic muscles of the hand?

Back 459

the secondary set that bypasses the wrist and attaches more distally to the digits

Front 460

All muscles of the wrist cross....

Back 460

the axes of rotation at the head of the capitate

Front 461

The specific action of each wrist muscle is determined by...

Back 461

the location of its tendon relative to each axis of rotation

Front 462

What elbow/forearm/wrist muscles are supplied by the ulnar nerve?

Back 462

- flexor carpi ulnaris

- flexor digitorum profundus (medial half)

- adductor pollicis

- palmaris brevis

- opponens digiti minimi
- abductor digiti minimi
- flexor digiti minimi (brevis)

- lumbricals (medial half)
- dorsal interossei
- palmar interossei

Front 463

Primary wrist extensors?

Secondary wrist extensors?

Back 463

- extensor carpi radialis longus
- extensor carpi radialis brevis
- extensor carpi ulnaris

- extensor pollicis longus
- extensor indicis
- extensor digitorum
- extensor digiti minimi

Front 464

Which is a more effective radial deviator, the extensor carpi radialis longus or brevis?

Back 464

longus, because it is farther from the anterior-posterior axis of rotation (has greater leverage/longer moment arm)

Front 465

The extensor carpi ulnaris assists in wrist extension, but it must also....

Back 465

neutralize the radial deviation of the extensor carpi radialis longus and brevis

Front 466

What is the main function of the wrist extensors?

Back 466

to position and stabilize the wrist for activities involving the fingers, especially while making a strong grasp or fist

Front 467

Why is contraction of the wrist extensors necessary when making a fist?

Back 467

to prevent the wrist from collapsing into flexion due to the strong flexion pull of the extrinsic finger flexor muscles, namely the flexor digitorum profundus and superficialis

they both cross palmar to the wrist and generate strong flexion torque at the wrist while flexing the fingers, thus the wrist extensors must contract every time a grasp is made

Front 468

What type of grip is produced by full wrist flexion with active flexion of the fingers?

Back 468

a very ineffective one

Front 469

At what angle do the wrist extensors ideally hold the wrist when making a strong grasp?

Back 469

30-35 degrees of extension to produce a strong force

Front 470

What produces lateral epicondylitis/epicondylalgia (tennis elbow)? Why?

Back 470

- activities requiring repetitive forceful grasp, since they tend to overwork the wrist extensors, especially the extensor carpi radialis brevis

- the small common origin of wrist extensors concentrates a large force on a small area

Front 471

How is lateral epicondylitis/epicondylalgia (tennis elbow) treated?

Back 471

- controlling inflammation
- proper stretching
- strengthening
- limiting activation of the extensor muscle group
- wearing a brace to limit motion, or wearing a cuff around the muscle bellies

Front 472

What type of grip will a person with paralyzed wrist extensors (e. g., damaged radial nerve) produce? How can this be remedied?

Back 472

- they will have great difficulty, even if the flexor muscles have normal strength

- will likely produce combined finger flexion and wrist flexion resulting in active insufficiency for finger flexors

- can be remedied by bracing (or even holding) in extension

Front 473

Primary wrist flexors?

Secondary wrist flexors?

Back 473

- flexor carpi radialis
- palmaris longus
- flexor carpi ulnaris

- flexor pollicis longus
- flexor digitorum superficialis
- flexor digitorum profundus

Front 474

Does the flexor carpi radialis pass through the carpal tunnel?

Back 474

no, it passes through a special groove within the transverse carpal ligament

Front 475

How does the sesamoid pisiform help the flexor carpi ulnaris?

Back 475

like the patella in the quadriceps, it improves the leverage of the tendon during combined wrist flexion and ulnar deviation

Front 476

What percentage of the population is missing one or both palmaris longi?

Back 476

10%

Front 477

The flexor carpi radialis is a radial deviator and the flexor carpi ulnaris is an ulnar deviator. Simultaneous activity of both is required to....

Back 477

flex the wrist in the pure sagittal plane

Front 478

Primary radial deviators of the wrist?

Secondary radial deviators of the wrist?

Back 478

- extensor carpi radialis longus
- extensor carpi radialis brevis

- extensor pollicis longus
- extensor pollicis brevis
- flexor pollicis longus
- abductor pollicis longus
- flexor carpi radialis

Front 479

Primary and secondary radial deviators have tendons that pass....

Back 479

lateral (or radial) to the anterior-posterior axis of rotation at the wrist

Front 480

Which extensor muscle has the greatest moment arm of all radial deviators? What kind of torque does it produce?

Back 480

- extensor pollicis brevis

- likely small, as it has a small cross-sectional area

Front 481

Primary ulnar deviators?

Secondary ulnar deviators?

Back 481

- extensor carpi ulnaris
- flexor carpi ulnaris

- trick question, there are no secondary ulnar deviators

Front 482

Explain how the extensor carpi radialis longus and flexor carpi radialis function as both agonist/antagonist and synergists.

Back 482

- they oppose each other in flexion/extension

- they work together in radial deviation

Front 483

Which of the following is not in the proximal row of carpal bones? ***

a. scaphoid
b. lunate
c. capitate
d. pisiform

Back 483

c. capitate

Front 484

The wrist allows motion in: ***

a. one plane
b. two planes
c. all three planes

Back 484

b. two planes

Front 485

Which of the following statements is true? ***

a. complete range of motion for wrist extension is typically 0 to 25 degrees
b. complete range of motion for wrist flexion is typically 0 to 80 degrees.
c. complete range of motion for wrist radial deviation is typically 0 to 60 degrees
d. complete range of motion for wrist extension is typically 0 to 15 degrees

Back 485

b. complete range of motion for wrist flexion is typically 0 to 80 degrees.

Front 486

Radial and ulnar deviation occur about: ***

a. an anterior-posterior axis of rotation
b. a medial-lateral axis of rotation
c. a longitudinal axis of rotation

Back 486

a. an anterior-posterior axis of rotation

Front 487

The wrist extensor muscles are activated when making a strong grip: ***

a. to prevent the fiingers from moving into an ulnar drift
b. to prevent the wrist from collapsing into unwanted flexion
c. to help expand the diameter of the carpal tunnel
d. to prevent the elbow from rotating into a flexed position

Back 487

b. to prevent the wrist from collapsing into unwanted flexion

Front 488

A person with paralysis of the wrist extensor muscles would most likely display weakness of a grasping or gripping activity because: ***

a. the long finger flexors are innervated by the same nerves as the wrist extensors
b. the wrist and the fingers will be in a flexed position, causing the long finger flexors to become actively insufficient
c. the wrist extensors are innervated by the same nerve as the intrinsic muscles of the hand
d. the wrist will likely end up in a hyperextended position

Back 488

b. the wrist and the fingers will be in a flexed position, causing the long finger flexors to become actively insufficient

Front 489

The ulnar deviator muscles of the wrist: ***

a. all course on the ulnar side of the anterior-posterior axis of rotation of the wrist
b. all course on the posterior side of the medial-lateral axis of rotation of the wrist
c. all prevent excessive flexion of the wrist
d. all course on the radial side of the anterior-posterior axis of rotation of the wrist

Back 489

a. all course on the ulnar side of the anterior-posterior axis of rotation of the wrist

Front 490

The most pure antagonist of the flexor carpi ulnaris is the: ***

a. flexor carpi radialis
b. extensor carpi ulnaris
c. extensor carpi radialis longus
d. palmaris longus

Back 490

c. extensor carpi radialis longus

Front 491

Which of the following nerves innervates all of the wrist extensor muscles? ***

a. median nerve
b. ulnar nerve
c. radial nerve
d. hypothenar nerve

Back 491

c. radial nerve

Front 492

The flexor carpi radialis, flexor carpi ulnaris, and palmaris longus: ***

a. attach proximally to the lateral epicondyle of the humerus
b. are innervated by the ulnar nerve
c. attach proximally to the medial epicondyle of the humerus
d. are innervated by the median nerve

Back 492

c. attach proximally to the medial epicondyle of the humerus

Front 493

Which of the following is not an action of the extensor carpi radialis longus? ***

a. extension of the metacarpophalangeal joints of all four fingers
b. radial deviation
c. wrist extension

Back 493

a. extension of the metacarpophalangeal joints of all four fingers

Front 494

The axis of rotation for all motions of the wrist is through which bone? ***
a. lunate
b. scaphoid
c. capitate
d. trapezium

Back 494

c. capitate

Front 495

The median nerve travels through the carpal tunnel. ***

a. true
b. false

Back 495

a. true

Front 496

Overuse and resultant inflammation of the wrist extensors may result in lateral epicondylitis. ***

a. true
b. false

Back 496

a. true

Front 497

Most muscles that originate off the lateral epicondyle of the humerus are innervated by the radial nerve. ***

a. true
b. false

Back 497

a. true

Front 498

All of the wrist extensors course anterior to the medial-lateral axis of rotation of the wrist. ***

a. true
b. false

Back 498

b. false (they course posterior to the medial-lateral axis)

Front 499

The wrist is a double-jointed system, consisting of the radiocarpal and midcarpal joints. ***

a. true
b. false

Back 499

a. true

Front 500

About 80% of the compressive force from the hand is transferred directly to the ulna. ***

a. true
b. false

Back 500

b. false (it is transferred to the radius)

Front 501

During radial and ulnar deviation, the roll-and-slide arthrokinematics occur in opposite directions. ***

a. true
b. false

Back 501

a. true

Front 502

The sesamoid bone located within the set of carpal bones is located on which side of the wrist? ***

a. ulnar
b. radial

Back 502

a. ulnar