chapter 5

Question 1

torque

Answer 1

the turning effect produced by a force

Question 2

torque causes change in

Answer 2

angular motion

Question 3

___ create torque about joints

Answer 3

muscles

Question 4

centric force

Answer 4

force line of action directed through COG
causes changes in linear translation

Question 5

eccentric force

Answer 5

force line of action not directed through COG
causes changes in linear translation and rotation

Question 6

force couple

Answer 6

2 eccentric noncolinear forces, equal and opposite in direction
causes change in rotation only

Question 7

force couple in relation to muscle and joints

Answer 7

2 or more muscles on opposing sides of a joint work together to provide joint stability or create movement

Question 8

moment arm

Answer 8

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

Question 9

moment arm represented by

Answer 9

r

Question 10

longer momentum arm: ___ turning affect of a force

Answer 10

increases

Question 11

shorter momentum arm: ___ turning affect of a force

Answer 11

decreases

Question 12

we push doors open as far away from hinges because

Answer 12

less force to create torque

Question 13

torque forumla

Answer 13

T= Fr

Question 14

torque unit

Answer 14

Nm

Question 15

a torque is vector or scalar

Answer 15

vector

Question 16

to fully describe a torque we need

Answer 16

specified axis of rotation, magnitude, sense

Question 17

sense of a torque is

Answer 17

direction
clockwise -, counterclockwise - (anatomically)

Question 18

what position at any joint do we have the largest moment arm

Answer 18

90 degree

Question 19

muscle moment arm length varies as

Answer 19

joint rotates

Question 20

resistance torque

Answer 20

external force caused by weight

Question 21

as weight is moved through joint ROM, ______ varies

Answer 21

resistance torque magnitude

Question 22

weight torque ___ as moment arm gets longer

Answer 22

increases

Question 23

weight torque ____ as moment arm gets shorter

Answer 23

decreases

Question 24

_____ opposes the resistance torque

Answer 24

muscle (effort) torque

Question 25

when muscle torque "wins" we have

Answer 25

movement against gravity

Question 26

static equilibrium

Answer 26

external forces sum to zero

Question 27

when can torques be added and subtracted

Answer 27

when around the same axis

Question 28

net torque

Answer 28

summing torques T clockwise + T counterclockwise

Question 29

center of gravity

Answer 29

point in a body or system where the entire mass may be assumed to be concentrate

Question 30

center of gravity is the point of

Answer 30

balance

Question 31

COG for shoulder torque

Answer 31

entire arm

Question 32

COG knee torque

Answer 32

low leg and foot

Question 33

COG hip torque

Answer 33

thigh, lower leg, foot

Question 34

COG height

Answer 34

55% female 57% male

Question 35

lift left arm away from side, COG shifts to the

Answer 35

left

Question 36

lift left arm in front of body, COG shifts

Answer 36

forward

Question 37

raise both arms away from side, COG shifts

Answer 37

upward

Question 38

when a body os projectile, COG follows a

Answer 38

fixed parabolic path

Question 39

stability

Answer 39

capacity of a body to return to equilibrium when displaced

Question 40

factors of COG and stability

Answer 40

height of center of gravity, size of base support, weight of object

Question 41

lower, wider, heavier = more or less stable

Answer 41

more