CH2: Biomechanics of Resistance Exercise

Question 1

proximal attachement

Answer 1

origin

Question 2

distal attachement

Answer 2

insertion

Question 3

toward the center of the body

Answer 3

proximal

Question 4

away from the center of the body

Answer 4

distal

Question 5

what is the pivot point of a lever?

Answer 5

fulcrum

Question 6

what is a first class lever?

Answer 6

muscle force and resistive force act on opposite sides of the fulcrum

Question 7

mechanical advantage

Answer 7

a ratio of the product of muscle force and the moment arm through which it acts, and the resistive force and the moment arm through which it acts, that is greater than 1.0

Question 8

what is a second class lever?

Answer 8

muscle force and resistive force acting on the same side of the fulcrum, with the muscle force acting through a much longer moment arm

Question 9

what is a third class lever?

Answer 9

muscle force and resistive force act on the same side of the fulcrum; with the muscle force acting through a much shorter moment arm

Question 10

what is torque (equation)

Answer 10

torque = force x moment arm (distance)

Question 11

how does bone insertion effect strength?

Answer 11

the further away from the joint center tendons are inserted on bone, the longer the moment arm through which muscle acts and therefore the heavier you can lift

Question 12

how does bone insertion effect speed?

Answer 12

the further away from the joint center tendons are inserted on bone, the more the muscle has to contract to make the joint move through a given range of motion

Question 13

left-right anatomical plane

Answer 13

sagittal

Question 14

front-back anatomical plane

Answer 14

frontal

Question 15

upper-lower anatomical plane

Answer 15

transverse

Question 16

ability to exert force

Answer 16

strength

Question 17

define work

Answer 17

force x distance

Question 18

define power

Answer 18

time rate of doing work ( P = w/t )

Question 19

how do you get a weight into SI units

Answer 19

multiply the mass (kg) by the local acceleration due to gravity (9.8m/s^2)

Question 20

what happens during recruitment?

Answer 20

the determining of which and how many motor units will be involved in a muscle contraction by neural control

Question 21

rate coding

Answer 21

rate at which motor units are fired

Question 22

what makes a muscle contraction stronger?

Answer 22

number of motor units, size of motor units, rate of firing of motor units

Question 23

pennate muscle

Answer 23

fibers aligned obliquely with the tendon, creating a featherlike arrangement

Question 24

how does the angle of pennation effect strength and velocity of shortening?

Answer 24

greater pennation = greater force, lower shortening velocity

lesser pennation = lesser force, greater shortening velocity

Question 25

muscle shortens because the contractile force is greater than the resistive force

Answer 25

concentric

Question 26

muscle lengthens because the contractile force is less than the resistive force

Answer 26

eccentric

Question 27

muscle length does not change since the contractile and resistive forces are equal

Answer 27

isometric

Question 28

what is the classic formula to standardize loads lifted across body sizes?

Answer 28

load lifted divided by body weight to the 2/3 power

Question 29

product of the accelerating force and the mass of the body being accelerated

Answer 29

inertial force

Question 30

bracketing technique

Answer 30

using lighter than normal and greater than normal resistance for a specific movement

Question 31

what does low resistance bracketing do?

Answer 31

allow a greater speed of movement, training the neuromuscular system to operate within that desired speed and acceleration range

Question 32

what does high resistance bracketing do?

Answer 32

develops greater force during acceleration at a lower speed, helps with force production

Question 33

formula for frictional force

Answer 33

F = coefficient of friction x normal force

Question 34

what are the two components of fluid resistance?

Answer 34

surface drag and form drag

Question 35

surface drag

Answer 35

friction of a fluid passing along the surface of an object

Question 36

form drag

Answer 36

how fluid presses against front or rear (frontal cross sectional area) of an object

Question 37

where are you most likely to get a back injury

Answer 37

lower two lumbar vertebrae, and between the lowest lumbar vertebrae and the top of the sacral vertebrae

Question 38

lordotic

Answer 38

curved inward

Question 39

kyphotic

Answer 39

rounded

Question 40

what does the Valsalva Maneuver do?

Answer 40

creates a rigid compartment of liquid in the lower torso and air in the upper torso which increases the rigidity of the entire torso