Test 2- Part 1: Biomechanics Flashcards Preview

KIN245 > Test 2- Part 1: Biomechanics > Flashcards

Flashcards in Test 2- Part 1: Biomechanics Deck (55):
1

Study of physical actions of forces

Mechanics

2

What two systems are mechanics divided into?

Statics & Dynamics

3

Study of systems that are in a constant state of motion, whether at rest w/ no motion or moving at a constant velocity w/out acceleration

Statics

4

Study of systems in motion with acceleration

Dynamics

5

This involves all forces acting on the body being in balance resulting in the body being in equilibrium

Statics

6

Description of motion and includes consideration of time, displacement, velocity, accleration, and space factors of a system's motion

Kinematics

7

Study of forces associated w/ the motion of the body

Kinetics

8

Load/effort =

Mechanical advantage

9

Using relatively small force (of effort) to move a much greater resistance

Mechanical advantage

10

Used to increase mechanical advantage

Machines

11

What are the four ways in which machines function?

1. Balance multiple forces
2. Enhances force in an attempt to reduce total force needed to overcome a resistance
3. Enhance ROM & speed of movement so that resistance may be moved further or faster than applied force
4. Alter resulting direction of the applied force

12

The musculoskeletel system provides 3 types of machines, what are they?

Levers (most common)
Wheel-Axis
Pulleys

13

Which machines are not found in the body?

Inclined plane
Screw
Wedge

14

A rigid bar that turns about an axis of rotation or a fulcrum

Lever

15

Point of rotation about which lever moves

Axis

16

In an arm, what represents the bars, axes, and applied force of a lever?

Bicep- force
Joint- axis
Bones- bars

17

All levers consist of what?

Axis (fulcrum)
Force (effort)
Load (resistance)

18

Axis between force &/or resistance

1st class lever

19

A F R

3rd class lever

20

A R F

2nd class lever

21

First class levers produce:

Balanced movements
Speed & ROM
Source motion

22

When does a first class lever produce speed & ROM?

When the axis is close to force (triceps in elbow extension)

23

When does first class levers produce source motion?

When axis is close to resistance (crowbar)

24

Where is force applied?

Where muscle inserts in bone (NOT BELLY OF MUSCLE)

25

Produces force movements, since a large resistance can be moved by a relatively small force

Second class levers

26

What are some examples of SCL?

Wheelbarrow
Nutcracker
Loosening a lug nut
Raising body on toes

27

Produces speed & ROM movements; the most common in humans. Requires a great deal of force to move even a small resistance

Third class levers (shoveling)

28

The turning effect of an eccentric force (moment of force)

Torque

29

Force applied off center or in a direction not in line with the center of rotation of an object w/ a fixed axis. Must occur for rotation to occur

Eccentric force

30

Equation for torque

Force x Force Arm = torque

31

Perpendicular distance between location of force application & axis

AKA?

Force arm

Moment arm & torque arm

32

How can you increase torque to help more easily move a relatively large resistance?

Increase force arm length

33

Distance between the axis and the point of resistance application

Resistance arm

34

Longer the force arm, the _______ ________ required to move the lever if the resistance & resistance arm stay constant

Less force

35

Shortening the resistance arm allows a __________ ____________ to be moved if force and force arm remain constant

Greater resistance

36

There is an inverse relationship between _______________________ and a proportional relationship between ______________________.

Length of the two lever arms
Force components & resistance components

37

Greater resistance or resistance arm requires what?

Greater force or a longer force arm

38

In a FCL, if the axis is right in the middle of the force arm and resistance arm, how much weight is needed to balance it?

An equal force

39

In a FCL, if the force arm becomes longer __ _____________ ________ of force is required to move a relatively larger resistance

A Decreasing amount

40

As the force arm becomes shorter, __ _____________ _________ of force is required to move a relatively smaller resistance

An increasing amount

41

In SCL, placing the reistance halfway between the axis & the point of force application provides a MA of:

2

42

In a SCL, what happens if you are to move the resistance closer to the axis?

The MA increases, but decreases the distance that the resistance is moved

43

In a SCL, what happens if you are to move the resistance closer to the force?

The less of a MA, but the greater the distance it is moved

44

In a TCL, a force greater than the resistance....

is ALWAYS required due to the resistance arm always being longer

45

In a TCL, what happens when the force application is closer to the axis?

There is an increase in the ROM & speed

46

In a TCL, what happens when when the force application is closer to the resistance?

It decreases the force that is needed

47

What do short fore arms & long resistance arms require in order to produce movement?

Great muscular force

48

The longer a lever is, the more effective it is in imparting __________

Velocity

49

For ______________, it is more desirable to have a short lever arm.

Quickness

50

Used primarily to enhance ROM & speed of movement in the musculoskeletal system

Wheel and axles

51

The center of the wheel & the axle both correspond to the ________

Fulcrum (axis)

52

If the wheel radius is __________ than the radius of the axle, then, due to the longer force arm, the wheel has a ____________ ______________ over the axis

Greater
Mechanical advantage

53

If application of force is reversed and applied to the axle, then the mechanical advantage results from the wheel
turning a _________________________

Greater distance & speed

54

Function to chance effective direction of force application

Single pulleys

55

Lateral malleolus. As peroneus longus contracts, it pulls toward it's bell (toward the knee). Using the lateral malleolus as a pulley, force is transmitted to plantar aspect of foot resulting in eversion/plantarflexion

Pulley example