biomech midterm 2

Question 1

frictional force

Answer 1

acts parallel to the interface of two surfaces that are in contact during motion or impending motion
- more friction in a static state

Question 2

frictional force formula

Answer 2

force required to move object / force of the object

Question 3

three ground reactional forces

Answer 3

• medial lateral sheer
• anterior posterior sheer
• vertical force

Question 4

inertial force

Answer 4

amount of force needed to move an object
(more inertia = harder to move)

Question 5

elastic force

Answer 5

the ability of something to deform and then return to its original force
(stiffness of material x change in length (kg/s))

Question 6

impulse

Answer 6

-indicates effort
- directly related to momentum
- measures the area under a curve

Question 7

countermoment jump

Answer 7

when the force value goes into the negative because the muscles are absorbing the change in force getting ready to jump

Question 8

energy

Answer 8

the capability to do work

Question 9

two types of energy

Answer 9

kinestic energy
potential energy

Question 10

kinetic energy (KE)

Answer 10

energy resulting from a movement

Question 11

potential energy (PE)

Answer 11

the capability to do work because of position or form

Question 12

kinestic energy formula

Answer 12

KP= 1/2 mv2

Question 13

potential energy formula

Answer 13

PE = magh

Question 14

impulse formula

Answer 14

force x dt (change in time)

Question 15

inertia formula

Answer 15

I = mp2

Question 16

work

Answer 16

efforts of a force applied over a distance

Question 17

work formula

Answer 17

w = F cos theta x displacement

Question 18

power

Answer 18

measures the amount of exploisiveness that occurs

Question 19

power formulas

Answer 19

power = work/time
or
power = F x V

Question 20

groudn reaction force

Answer 20

• contact forces
• 6 outputs on force plate (3 forces, 3 moments)

Question 21

center of pressure use

Answer 21

clinic use for orthotics

Question 22

kinematics reference systems

Answer 22

x, y, and z

Question 23

kinematics axes

Answer 23

medial - lateral, anterior-posterior, vertical

Question 24

kinesmatic planes

Answer 24

sagital (left to right), frontal, transverse (top - bottom)

Question 25

kinematic coordinate method

Answer 25

location of marker w reference system

Question 26

Optotrak motion capture system

Answer 26

active merker system traked online
- used to make simiulations and video games

Question 27

three degrees of freedom on a rigid body in space (2D, sag plane)

Answer 27

• translation parameters (x, y)
  - anterior-posterior
  - upward - downward
• rotaion parameter (z)
  - flexion - extension

Question 28

relative angles

Answer 28

• joint position
• joint movement
• rate

Question 29

absolute angle

Answer 29

• segmental angular postion
• displacement
• acceleration and velocity relative to the right horizontal

Question 30

six degrees of freedom on a rigid body in space (3D)

Answer 30

• translation parameters (x, y, z)
  - anterior - posterior
  - upward - downward
  - medial - lateral
• rotation parameters (theta x, y, z)
  - abduction - adduction
  - internal - external
  - flexion - extension

Question 31

radius of gyration - the inertial force

Answer 31

• how concentrated the mass of those segments are away frmo the COM

Question 32

segmental equation of motion (p)

Answer 32

relative to the mass of the object
- what is the radius of the segment
- p = SL x ROG/SL

Question 33

difference between impulse and resultant force vector

Answer 33

• impulse only takes into consideration the vertical forces
• resultant force vectors takes into consideration vertical and horizontal forces ( which produce a magnitude and direction)