interactions

Question 1

Origin terms

Answer 1

• Proximal
• Medial
• Superior

Question 2

Insertion terms

Answer 2

• Distal
• Lateral
• Inferior

Question 3

What is the line of action

Answer 3

line between origin and insertion
(tendon to tendon)

Question 4

what do muscles do

Answer 4

generate force

Question 5

what is the equation for torque

Answer 5

T= F*r
torque = force * moment arm

Question 6

what is torque

Answer 6

the tendency of a force to rotate and object around an axis

Question 7

what is the moment arm

Answer 7

perpendicular distance from the line of axis to the center of rotation of a joint

Question 8

what does moment arm depend on

Answer 8

joint angle and origin and insertion

Question 9

why are multiple muscles active at a joint

Answer 9

to preform an action

Question 10

what is net joint torque

Answer 10

the summation of all torques produced by muscles acting at a joint

Question 11

which torques does net torque balance

Answer 11

• weight of body segment
• motion of body segment
• external forces

Question 12

when is a concentric movement

Answer 12

when internal torque is greater than external torque

Question 13

when is a eccentric movement

Answer 13

when external torque is greater than internal torque

Question 14

when is a isometric movement

Answer 14

when internal and external torque are equal

Question 15

what is a fulcrum

Answer 15

point about a lever rotates (axis)

Question 16

what are levers classified according to

Answer 16

Axis, Resistive force and Motive force
(ARM)

Question 17

what is a first class lever

Answer 17

axis between motive and resistance force (ex. elbow extension and plantar flexion)

Question 18

what is a second class lever

Answer 18

resistive force in the middle
(ex. push ups)

Question 19

what is a third class lever

Answer 19

motive force in the middle (ex. most joints)

Question 20

how to calculate mechanical advantage

Answer 20

moment arm (force)/moment arm (resistance)

Question 21

what does it mean if force MA is greater than resistance MA

Answer 21

• mechanical advantage is greater than 1.0
• low force is needed to overcome resistance
• resistance moved through limited ROM

Question 22

what does it mean id resistance MA is greater than force MA

Answer 22

• mechanical advantage is less than 1.0
• larger force is needed to overcome resistance
• resistance is moved through larger ROM

Question 23

what are majority of levers types in the human body

Answer 23

third class levers

Question 24

muscle force production must exceed what

Answer 24

resistance force

Question 25

define uniarticulate

Answer 25

muscle cross one joint

Question 26

define biarticulate

Answer 26

muscles cross two joints

Question 27

define multiarticulate

Answer 27

muscles cross multiple joints

Question 28

what is special about biarticulate muscles

Answer 28

produce force and contribute to two joint torques simutanusly

torque produced at one joint depends on the angle of the other joint

Question 29

What is Lombards paradox

Answer 29

from sit to stand both the rectus femoris and hamstrings contract when they shouldn’t because both are antagonist
-antagonist action allows biarticulate muscles to act like tendons

Question 30

what are the 5 steps in muscle control formula

Answer 30

1. identify joints that are moving
2. identify planes of movement
3. identify effects of external torques
4. identify type of muscle action
5. identify muscles that are controlling/producing movement

Question 31

how do muscles produce force

Answer 31

when sarcomere contracts ie. myosin interacting with actin

Question 32

what are the units for torque

Answer 32

newton meters (N*m)