Biomechanics Unit 4 Part 2

Question 1

What forms the wrist joint

Answer 1

distal radius, structures in ulnocarpal space, carpal bones and proximal ends of metacarpals

Question 2

proximal row of carpals bones

Answer 2

triquetrum, lunate, scaphoid

Question 3

distal row of carpals

Answer 3

hamate, capitate, trapezoid, trapezium

Question 4

odd bone out

Answer 4

pisiform - anterior to triquetrum - easily palpated at pinky

Question 5

What inserts into the pisisform bone

Answer 5

flexor carpi ulnaris (flexes and adducts the wrist)

Question 6

The wrist is a stable joint

Answer 6

YES due to intricate ligamentous structures

Question 7

What carpal bones articulate with the radius - what kind of joint

Answer 7

lunate and scaphoid - condyloid joint (oval shaped condyloid - capral- fits into depression - radius)

Question 8

What articulates with the ulna

Answer 8

triquetrium via triangular shaped inter-articular disc which occupies ulnocarpal space (apex: styloid procress of ulna and base: ulnar notoch of radius)

Question 9

what movemetns does the wrist do and numbers

Answer 9

flexion (90) and extension (80)

ab (15-20) and adduction (35)

Question 10

Joints of the hand include….

Answer 10

CMC, IMC, MCP, PIP, DIP

Question 11

Which is the most freely moving CMC joint and why - type of joint

Answer 11

first - trapezium and thumb - allows us to oppose other figners - saddle join

Question 12

what type of joint is the MCP joints

Answer 12

condlyoid

Question 13

type of joint is PIP and DIP

Answer 13

hinge

Question 14

Which metacarpals are pretty much immobile

Answer 14

second and third

Question 15

what ROM do 4th and 5th MC produce

Answer 15

10-15 4th and 20-30 5th

Question 16

MCP joints
flexion:
E:

Answer 16

F: 90
E: depends on laxity of individual

Question 17

PIP and DIP only allow what movement and which is has a greater ROM

Answer 17

flexion and etension
PIP - more flexion - 100-110
DIP: 90

Question 18

Thumb ROM
flexion (what is it)
extension) 
extension
abuduction

Answer 18

F: moving across the palm - 15
E: moving to side of palm -20
Ab: away from hand - 60

Question 19

What influences wrist movements

Answer 19

it’s position and whether the fingers are extended or not –> changes functional msucle length

Question 20

Components of the spine

Answer 20

24 unfused vertebrae (7 cervical, 12 thoracic, 5 lubar,, sacrum (5) and coccyx (4)

Question 21

describe a vertebrae

Answer 21

flat, round body palced anteriorly and centrally - vertebral body. Arch of bone (neural arch) that froms spinal foramen (spinal cord runs thorguh), spinous process projects posteriorly inferiorly and centrally, two transverse processes laterally

Question 22

Function of transverse processes

Answer 22

anchorage sites for ligaments and muscles which stabilise and move the spine

Question 23

Articulations of the vertbrae are….

Answer 23

vertebral body - IV disc and two facet joints (upper and lower) on each side

Question 24

two functions of IV disc

Answer 24

bear and distribute load, restrain excessive motion

Question 25

What makes the IV disc

Answer 25

outer annulus fibrosus and inner nucleus pulposus (sits centrally in most, posteriorly in lumbar)

Question 26

Describe the nucleus pulposus

Answer 26

formed by strong hydrophilic gel enmeshed in random collagen matrix

Question 27

function of nucleus pulposus

Answer 27

gel produces a high water content therefore elevated nucleus pressure - balanced the applied compressive stress –> increased applied stress water driven out unitl new steady state is reached, if stress decreases then rehydrates

Question 28

How much height do we lose during the day and why

Answer 28

about 1cm as the mechanism of rehydration can’t be maintained for a long period of time therefore results in decreased disc height

Question 29

describe the annulus fibrosus

Answer 29

tough layer made of collagen fibres - form concentric layers (lamellae) with alternating orientations of collagen fibres - resists high bending and torsional loads

Question 30

What is the most mobile region of the spien

Answer 30

cervical spine

Question 31

which cervicl vertebrae are special

Answer 31

C1 (atlas)and C2 (axis)

Question 32

Why is the atlas different

Answer 32

no body but has an oval fossa that articulates with the axis

Question 33

describe the axis

Answer 33

articular process projecting superiorly called the dens that articulates with the oval fossa of atlas - allows the atlas to rotate

Question 34

What is different about thoracic vertebrae

Answer 34

attach to ribs

Question 35

Where do ribs articulate on thoracic vertebrae

Answer 35

head attaches to body of vertebrae on same level and (2-9) above it (via costal facet joints) and tubercle attaches to transverse process

Question 36

The ribs allow extra mobility of the thoracic spine

Answer 36

FALSE limit mobility with only limited degree of flexion and extension

Question 37

What makes the lumabr vertebrae different

Answer 37

They ahve larger bodies as they carry significantly larger loads

Question 38

What joins the sacrum to the pelvis

Answer 38

fibrous joints – small amount of motion

Question 39

ROM of spine

Answer 39

varies among individuals depending on age and sex

Question 40

Flexion and extension of spine

Answer 40

flexion: forward
extension: backwards
greatest in cervical (around 30)
lowest in thoracic (3 degrees)

Question 41

Lateral bending

Answer 41

most - cervical (non between occiput, C1 and C2)

least -thoracic

Question 42

Difference of load on the spine between relaxed sitting and standing

Answer 42

The moment arm of the upper body weight is larger when relaxed sitting therefore back muscles must produce a larger force to counter act the resistive load (causing more compression on spine)