Principles Flashcards Preview

DPT Biomechanics > Principles > Flashcards

Flashcards in Principles Deck (43):
1

T or F 'z' is positive to the person's right

T

2

which directional plane is positive anteriorly (direction of forward progression for gait)

x

3

what axes form the frontal (coronal) plane

vertical (y) and mediolateral (z)

4

what axis does frontal plane motion rotate about?

x axis (anteroposterior)

5

Transverse Plane is formed by

the anteroposterior (x) and mediolateral (z) axes

6

what axis does motion in the transverse plane rotate about

vertical

7

sagittal plane is formed by

the vetical (y) and antero-posterior (x) axes

8

motion in the sagittal plane rotates about which axis

mediolateral (z) axis

9

what is kinematics? example?

description of motion
displacement, velocity, acceleration

10

what is kinetics?

description of forces
forces, moments

11

what is translation?

linear kinematics

12

what is angular displacement measured in?

theta. degrees

13

what is true about linear and angular motion regarding human movement

it's usually a combination of the two

14

What's the difference between external and internal forces?

external - forces acting on the body (gravity, a weight in hand)
internal - forces acting inside the body (muscle force, passive constraints)

15

what is the moment arm defined as

perpendicular distance between line of action of the force and the axis of rotation

16

hyper/hypo-mobile, smooth/jerky is an example of which kind of description of movement

Qualitative

17

The standard for 3-dimensional analysis is

y (vertical)
x (anteroposterior)
z (mediolateral)
International Society of Biomechanics standard

18

T o F Scalar Quantities can only add quantities of the same units

T

19

which quantity have magnitude AND direction

vector

20

mass is a

scalar

21

weight is a

vector (mass x gravity)

22

distance is a

scalar

23

displacement is a

vector

24

point at which the entire mass of an object can be considered to be located

COM

25

Balance point for an object

center of gravity

26

Where is the Whole Body COM

S2

27

Newtons 1st Law

object at rest will stay at rest unless acted on by an unbalanced external force. object in motion will stay in motion unless acted on by an unbalanced external force

28

When is something in Static equilibrium

when the sum of the forces = 0

29

Newtons Second Law

sum of Forces = ma

30

Newtons third law

for every action, there is an equal and opposite reaction

31

collinear force system

forces act on the same segment
(tug of war)

32

concurrent force system

lines of action are at angles to each other

33

First Class Lever

See-Saw
external force and internal force on opposite sides of fulcrum

34

Second Class levers

wheelbarrow
fulcrum and internal force on opposite side of the external force

35

third class levers

fulcrum and external force on opposite sides of internal force

36

which lever is very common in the body

third class

37

What happens when you multiply a vector by a scalar

get a vector

38

How do you decrease stability

decrease base of support (BOS) and move COM further from BOS

39

To determine the stiffness of a tissue from its stress-strain curve, I would

calculate the slope in the linear (elastic) portion of the curve

40

Which of the following is not a primary component of connective tissue?
fibrous proteins
blood vessels
ground substance
cell

blood vessels

41

GAG molecules have a negative charge. What important effect does this have on the ground substance of connective tissue?

the molecules are hydrophilic and attract water into the tissue

42

When a biological tissue is loaded quickly, we would expect it to respond with a _______ response than when it is loaded slowly.

stiffer

43

To effectively stretch a biological tissue, you must be in the _____ region of the load-deformation (stress-strain) curve

plastic