Week 1: Basic biomechanimal concepts

Question 1

what are the numerous fields that contribute to biomecs

Answer 1

math, physics, engineering
biologyc, chem, physiology
health sciences, med

Question 2

where is biomecahncs used

Answer 2

sports, ergonomics and design, medecine and surgery (cardio, neuro, ortho) rehab

Question 3

fancy definition of kinematics

Answer 3

study of motion without regard to the forces that cause that motion

Question 4

velocity, accetable, jt angles are associated with kinematics or kinetics

Answer 4

kinematics

Question 5

torque is associated to kinetics or kinematics

Answer 5

kinetics

Question 6

in kinematics what are the 2 types of movement possiblr

Answer 6

1) translation
2) rotation

Question 7

explain translation in terms of kinematics

Answer 7

all points on body move the same distance

Question 8

explain rotation in terms of kinematics

Answer 8

there is a stationary point (COR) and all points move in an arc around that stationary point

Question 9

what type of movement is most common in the buman body and explai n

Answer 9

rotation
=rotation occurs at the joints
=there are some translations that occur with the rotation but very small movements

Question 10

injuries can increase rotational or translational movment

Answer 10

translation

Question 11

what are the 4 kinematic variables

Answer 11

position
displacement
velocity
acceleration

Question 12

explain position

Answer 12

where you are

Question 13

explain displacement

Answer 13

change in position

Question 14

explain velocity (formula)

Answer 14

change in position/time
displace/time

Question 15

explain accelration (fromaula)

Answer 15

change in velocity/time

Question 16

velocity has two components and speed only has one. what are the componenets of velocity

Answer 16

its a vector so it has both magnitude and direction

Question 17

what are the 3 axis in the coordinate system

Answer 17

anterior/posterior
superior/inferior
medial/lateral

Question 18

what are the 3 planes of the coordinate system

Answer 18

saggital
frontal/coronal
transverse

Question 19

sagital splits the body into what

Answer 19

l/r halves

Question 20

frontal splits the body into what

Answer 20

anterior and psoterior halves

Question 21

transverse splits the body into what

Answer 21

up and dwon

Question 22

planes rotate around the axis that are BLANK to it

Answer 22

perpendicular

Question 23

what are the 2 axis of the sagital plane

Answer 23

super/inferior
anterior/posterior

Question 24

what are the 2 axis of the frontal plane

Answer 24

super/inf
med/lat

Question 25

what are the 2 axis of the transverse plane

Answer 25

med/lat ant/post

Question 26

explain the axis and plane of shoulder abduction

Answer 26

moves in the coronal plane along the ant/post

Question 27

explain the axis and plane of shoulder flexion

Answer 27

rotation in sagital plane about med/lat

Question 28

global coordinate system has how many dimensions

Answer 28

3

Question 29

what is the difference between global and local coordinate systems

Answer 29

global: fixed to some point in space local: fixed to a rigid body (ex: femur)

Question 30

explain local/anatomic coordinate system

Answer 30

seperate coordinate systems per segment and joint angles is how they move relative to each other

Question 31

two local coordinates (eg: knee and femur) are often compared to determine what

Answer 31

joint angles

Question 32

in our global coordinate system, how many degrees of freedom do we have

Answer 32

6 degrees of gfreedom

Question 33

what does it mean to have 6 degrees of freedom of movement

Answer 33

it means there are 6 wways to move in 3 dimensional space

Question 34

with 6 degrees of freedom you can translate and rotate along what axes

Answer 34

3 axes

Question 35

true or false: there are 6 DOF in joints of the body

Answer 35

false, there are less than 6 DOG in joints because of contraints (joint surfaces, ligaments, etc)

Question 36

how can we translate along the 3 axis

Answer 36

forward/bnackwars right/left up/down

Question 37

how can we rotate along the 3 axis

Answer 37

roll pitch yaw

Question 38

what is force

Answer 38

a push or pull acting on a body (F=massx acceelation)

Question 39

what is the formula for force

Answer 39

F= mass x acceleration

Question 40

what is the units for force

Answer 40

newtons ( N= kg*m/s2)

Question 41

name some common forces:

Answer 41

muscles, ligaments, ground reaction, weight (gravity)

Question 42

what is moment (torque)

Answer 42

force acting at a distance from center of rotation

Question 43

what is the formula for moment/torque

Answer 43

M = moment arm x force

Question 44

what is the unit of moment/torque

Answer 44

measured in New*Meters Nm= kg*m2/s2

Question 45

what is newtons 1st law

Answer 45

an object remains at rest (or continutes moving at a constant velocity) unless acted upon by an unbalanced extermal force SigmaF=0. SigmaM=0 (sum of all forces/torques = 0 )

Question 46

what is the significance of newtons 1st law

Answer 46

will be used to help solve forecs and moments in static bodies

Question 47

what is newtons 2nd law:

Answer 47

If there is an unbalanced force acting on an object, it produces an acceleration in the direction of the force, directional proportional to the force

Question 48

what is the formula for newtons 2nd law

Answer 48

F=ma

Question 49

what is the significace of newtons 2nd law

Answer 49

will be used to help solve forces and moments in accelerating bodies

Question 50

what is newtons 3rd law:

Answer 50

for every action (force), there is a reaction (opposing force) of equal magnitude but in the opposite direction

Question 51

what is the significance of the 3rd newton law

Answer 51

will be used to measure external forces acting on the body (ex: GRF)

Question 52

what is anthropometry

Answer 52

study of the physical measurements of the human body

Question 53

what do anthropometrics measure

Answer 53

segment length, segment mass, centre of mass location, radius of gyration (resistance to rotation)

Question 54

what is the centre of mass/center of gravity

Answer 54

point on which any line passing through it divides the bodys segments mass in half

Question 55

true or false: around the centre of mass, the mass is equally distributed around this point

Answer 55

truw

Question 56

does center of mass change with movement

Answer 56

yes

Question 57

are you more stable when your center of mass is in or OUTSIDE your pass of sjupport

Answer 57

in (you are less stable outside your base of support)

Question 58

what do motion capture systems do for kinematics

Answer 58

measure position (calculate velocity, acceleration ,joint angles)

Question 59

what are the current motion capture systems we are using

Answer 59

optoelectric electromagnetics ultrasound

Question 60

historically, what was used to capture motion

Answer 60

cameras and movie/television cameras

Question 61

what is the principle of optoelectric systems

Answer 61

markers emit (active) or reflect (passive) infrared light, cameras identity marker position

Question 62

what is the principle of electromagnetic systems

Answer 62

receivers (markers) pick up magnetic field emitted by a transmitter

Question 63

what are the advantages of optoelectric systems

Answer 63

high accuracy can be wireless not influenced by materials

Question 64

what are the disadvantages of optoelectric systems

Answer 64

markers can be occucluded (blocking each other) post-processing time with some systems

Question 65

what iare the advantages of electromagnetic systems

Answer 65

clear line of sight not necessary

Question 66

what are the disadvantages of electromagnetic systems

Answer 66

metal interferance limited range wires

Question 67

what are the instrumentations used in biomechanics

Answer 67

1) cameras 2) optoelectric, electromagnetic, ultrasound 3) inertial sensors 4) markerless systems

Question 68

explain inertial sensors for motion caputuring

Answer 68

combination of accelorometers (acceleration/inclination), gyroscopes (orientation), magnetometers (horizontal position)

Question 69

explain markerless systems

Answer 69

multiple cameras getting 3D image (use contrast, machine learning = computer can automatically detect and label joints)

Question 70

what are electrogoniometers used for and how

Answer 70

to measure joint angles during movement by change in electrical current when device is bent

Question 71

what is the advanaage of electrogoniometeers

Answer 71

cheap, simple

Question 72

what are the disadvantages of electrogoniometers

Answer 72

difficult to align, movement can be limited by device

Question 73

what do acceleratomets measure

Answer 73

acceleration

Question 74

what can accelorometeres determine

Answer 74

net forec (F=ma), velocity or disaplacement

Question 75

what is the instrumentation used for kinetics

Answer 75

force transducers and force plates dynammometers electromyography pressure sensors

Question 76

what do dynamometers measure

Answer 76

strength (force) ex: isokinetic dynamometers, hand help., grip strenght

Question 77

what does electromyographt measure

Answer 77

measures muscle activation during different activities

Question 78

true or false: electromyography measures muscle force

Answer 78

false, it does not

Question 79

when are pressure sensors usually used in kinetics

Answer 79

often used to measure plantar pressure