Mechanics: Unit 4 Upper limb + spine (online)

Question 1

what are the 5 parts of the upper limb?

Answer 1

shoulder girdle
arm
forearm
wrist
hand

Question 2

What are the 3 synovial joints of the shoulder? what is the other articulation

Answer 2

glenohumeral
acromioclavicular
sternoclavicular

other is scapulothoracic (bone-muscle-bone)

Question 3

What type of joint is the glenohumeral joint and what forms it?

Answer 3

synovial ball and socket formed from the humeral head and the glenoid fossa of the scapula

Question 4

Is the glenohumeral joint stable? which structures help stability?

Answer 4

no the shallow glenoid fossa gives increased ROM but decreased stability so we need the glenoid labrum, joint capsule and rotator cuff muscles to stabilise

Question 5

What movement do the rotator cuff muscles prevent? how?

Answer 5

anterior and posterior displacement of glenohumeral joint by pushing on the humeral head
inferior displacement

Question 6

Which ligaments prevent upward movement of the scapula?

Answer 6

coracoclavicular ligaments

Question 7

What structures prevent movement at the acromioclavicular joint?

Answer 7

thorax and mucle attachments

Question 8

What is the only joint that connects the shoulder girdle to the trunk?

Answer 8

sternoclavicular

Question 9

How does the clavicle elevate at the sternoclavicular joint?

Answer 9

elevates between 0-90 degrees: 4 degrees for every 10 degrees of arm elevation
past this minimal

Question 10

What structure is the axis for rotation of the clavicle during elevation and depression?

Answer 10

costoclavicular ligaments

Question 11

Why is the scapulothoracic articulation not a joint in the truest sense?

Answer 11

there is no direct ligamentous or bony attachment it is bone-muscle-bone

Question 12

What two muscles form the scapulothoracic articulation?

Answer 12

serratus anterior

subscapularis

Question 13

Where does serratus anterior originate and insert?

Answer 13

ribs 1-8/9

on scapula along vertebral border

Question 14

Where does subscapularis originate and insert?

Answer 14

subscapular fossa

lesser tubercle of the humerus

Question 15

What movement does serratus anterior do?

Answer 15

strong abductor in pushing/pulling

prevents scapula winging

Question 16

What movement does subscapulris do?

Answer 16

medially rotates humerus

Question 17

What are the 4 rotator cuff muscles?

Answer 17

subscapularis
infraspinatus
supraspinatus
teres minor

Question 18

What are the main movements of the shoulder referred to?

Answer 18

shoulder elevation and depression

Question 19

What is shoulder elevation called in the

a) sagittal plane?
b) frontal/coronal plane?

Answer 19

a) forward flexion

b) abduction

Question 20

What is shoulder depression called in the

a) sagittal plane?
b) frontal/coronal plane?

Answer 20

a) backward extension

b) adduction

Question 21

What are internal/external rotation of the shoulder?

Answer 21

rotation about the longitudinal axis of the humerus

Question 22

What are horizontal flexion and extension?

Answer 22

with arms abducted parallel to the ground
flexion = move arm across body
extension = move arm behind body

Question 23

What is the ROM of the shoulder for

a) backward extension?
b) abduction?
c) adduction
d) internal and external rotation?
e) horizontal flexion?
f) horizontal extension?

Answer 23

a) 60
b) 180
c) 75
d) 90 each
e) 135
f) 45

Question 24

Which articulation of the shoulder is most prone to dislocation?

Answer 24

anterior dislocation of glenohumeral joint

Question 25

When does anterior dislocation of glenohumeral joint occur?

Answer 25

heavy blow applied to abducted, horizontally extended arm

Question 26

When the arm is in a position of abduction and horizontal extension what type of lever system are the shoulder and arm acting as?

Answer 26

1st class lever system

Question 27

With the arm fully extended is the effort force working at a mechanical advantage or disadvantage at the acromion? What does this mean the resistance force must be?

Answer 27

MA so a small effort force can cause dislocation resistance force must be much larger (eg 10x)

Question 28

What are the 3 articulations of the elbow joint?

Answer 28

humeroradial humeroulnar proximal radioulnar

Question 29

What does the radial head articulate with on the humerus?

Answer 29

capitellum

Question 30

What does the ulnar head articulate with on the humerus?

Answer 30

trochlea

Question 31

Which articulations of the elbow allow a) flexion/extension? b) pronation/supination?

Answer 31

a) humeroradial and humeroulnar | b) proximal radioulnar

Question 32

Where does the axis of rotation for flexion/extension of the elbow pass through?

Answer 32

trochlea

Question 33

What is the ROM of flexion/extension of the elbow?

Answer 33

140 of flexion | 0 of extension

Question 34

What does the radial head rotate in during pronation/ supination of the elbow?

Answer 34

radial notch of the ulna

Question 35

What structure binds the radius and ulna together at the proximal radioulnar joint?

Answer 35

annular ligament

Question 36

What is the ROM of pronation/supination at the elbow ?

Answer 36

70 pronation | 80 supination

Question 37

How many degrees of flexion, pronation and supination at the elbow are required for daily activites at the elbow?

Answer 37

100 of flexion from 30-100 degrees | 100 of pro/sup from 50 degrees

Question 38

Which structure resistes A/P and P/A forces at the elbow?

Answer 38

olecranon

Question 39

Which structures resist lateral and medial forces at the elbow?

Answer 39

collateral ligaments

Question 40

Which collateral ligament of the elbow prevents a) abduction? b) adduction?

Answer 40

a) ulnar/medial | b) lateral

Question 41

Which collateral ligament of the elbow is worse at its job? which structure helps it?

Answer 41

lateral | anconeus muscle

Question 42

Why is the elbow joint subject to such high forces?

Answer 42

moment arm of muscles are much smaller than the moment arms of external forces so the muscle force must be very large

Question 43

What is the radiocarpal joint between?

Answer 43

lunate and scaphoid and distal radius

Question 44

What type of joint is the radiocarpal joint?

Answer 44

condyloid

Question 45

What movements occur at the radiocalpar joint?

Answer 45

flexion-extension abduction-adduction circumduction

Question 46

How do the triquetrum and ulna articulate?

Answer 46

via triangular intra-articular disc in ulnocarpal space

Question 47

Which wrist joint allows for flexion more than extension?

Answer 47

midcarpal

Question 48

Which wrist joint allows for extension more than flexion?

Answer 48

radiocarpal

Question 49

How much ROM at the wrist for a) flexion? b) extension? c) abduction? d) adduction?

Answer 49

a) 80 b) 70 c) 15 d) 35

Question 50

What is the most functional position for an immobilised wrist joint?

Answer 50

fixed extension of 15 degrees

Question 51

What bones are in the hand?

Answer 51

5 metacarpals and 14 phalanges

Question 52

What type of joint are the carpometacarpals?

Answer 52

saddle

Question 53

Why is the 1st CMC joint so important? what bones does it lie between?

Answer 53

most freely moving to allow opposition of thumb | trapezium and 1st metacarpal

Question 54

Where are the intermetacarpal joints?

Answer 54

in the joint capsules of the CMC, formed by articulations between proximal ends of adjacent metacarpals

Question 55

What type of joint are the metacarpophalangeal joints?

Answer 55

condyloid

Question 56

What movements does a a) hinge joint b) saddle joint allow?

Answer 56

a) flexion/extension | b) flexion/extension, abduction/adduction

Question 57

What type of joint are the interphalangeal joints?

Answer 57

hinge

Question 58

How does the maximum amount of flexion at the metacarpo- phalangeal joint vary from finger to finger?

Answer 58

generally decreases from the fifth to the second joint. At the fifth joint (little finger) it is around 95 to 100 degrees and at the second joint (index finger) it is about 70 degrees.

Question 59

What is metacarpophalangeal extension dependent on?

Answer 59

ligamentous laxity

Question 60

Is flexion greater at the proximal or distal interphalangeal joints?

Answer 60

proximal

Question 61

What is extension of the interphalangeal joint beyond neutral called?

Answer 61

hyperextension

Question 62

Do the MCP joints allow more flexion in the thumb or the fingers?

Answer 62

fingers 90 | thumb can be 30-90

Question 63

What movements does the CMC of the thumb allow?

Answer 63

flexion extension abduction rotation

Question 64

How does movement of the wrist affect hand movement?

Answer 64

muscles that move the digits are found in the forearm but their tendons cross the wrist and as it moves it alters their functional length

Question 65

Name the five regions of the spine.

Answer 65

``` cervical thoracic lumbar sacral coccygeal ```

Question 66

How many vertebrae are found in the a) cervical region? b) thoracic region? c) lumbar region?

Answer 66

a) 7 b) 12 c) 5

Question 67

What is the spine made up of?

Answer 67

24 unfused vertebrae sacrum (5 fused) coccyx (4 fused)

Question 68

What is the function of the intervertebral discs ?

Answer 68

bear and distribute load | restrain excessive motion

Question 69

What forms the inner nucleus pulposus?

Answer 69

hydrophilic gel in a collagen matrix

Question 70

What forms the annulus fibrosus? why is this helpful?

Answer 70

tough collagen form concentric layers of lamellae | alternating orientations help to resist bending and torsion loads

Question 71

Describe C1

Answer 71

no body ring within which an oval fossa articulates with axis rotates about dens

Question 72

Describe C2

Answer 72

superior articular process, the dens, joins to form a synovial joint with the oval fossa

Question 73

What is each thoracic vertebrae attached to?

Answer 73

a pair of ribs - head of rib to vertebral body - tubercle of rib to transverse process

Question 74

Why are the lumbar spine's vertebral bodies bigger?

Answer 74

they are subjected to higher loads

Question 75

What links the spine to the pelvic girdle?

Answer 75

sacrum

Question 76

Which spinal region has a) the most mobility? b) the least mobility?

Answer 76

a) cervical | b) thoracic

Question 77

What part of the spine is there no lateral bending?

Answer 77

occipital bone and C1 | C1 and C2

Question 78

How does rotation change along the spine?

Answer 78

greatest C1 and C2 then decreases down the spine

Question 79

As the moment arm of the upper body weight increases does the loading on the spine increase or decrease?

Answer 79

increases

Question 80

Is the load on the lumbar spine more when standing or sitting?

Answer 80

sitting

Question 81

Give the carpal bones in order from right to left if looking anteriorly at the right hand

Answer 81

scaphoid lunate triquetrum pisiform ``` (new row) traezium trapezoid capitate hamate ```

Question 82

Where is the pisiform positioned? what significance does it have?

Answer 82

anteriorly to triquetrum (can be palpated) it is the point of insertion of the flexor carpi ulnaris muscle and increases the lever arm

Question 83

What does flexor carpi ulnaris do?

Answer 83

flexes and adducts the wrist