1 ' Biomechanics Flashcards Preview

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Flashcards in 1 ' Biomechanics Deck (43):
1

Forces are classified as either

Internal or external

2

Internal

Act within the object or system

3

External

Act on an object through some interaction

4

Forces contribute to the acceleration of resistance in a single plane

True

5

Stabilizer

A muscle whose torque prevents moment at a joint

6

Prime mover

The muscle that causes an action

7

Asymmetrical load

A single-sided or unbalanced load or weight distribution

8

Balance

A stable state characterized by the cancellation of all forces by equal opposing forces

9

Static equilibrium

Sum of all external forces acting on the body equal zero; determine the ability to balance

10

Energy

Capacity to do work

11

Work

Transfer of energy by a force acting to displace the body; equal to the product of the force and the distance through which it produces movement

12

Work can be either prosit ice or negative as long as there is movement

True

13

If weight is pressed overhead, the action is positive work; when the weight is lowered back down, the action is considered negative work

True

14

Mechanical energy has two forms:

Kinetic energy and Potential energy

15

Kinetic energy

Energy possessed by the body due to its motion

16

Potential energy

Suggests no movement; implies energy due to position, such as with a stretched rubber band muscle

17

The stretch-shortening cycle (SSC) uses kinetic energy transferred into potential energy and back into kinetic energy for increased force output

True

18

Power

Time rate of doing work (work divided by time)

19

Power output depends on the muscle's contractile velocity; as it increases, maximal force decreases

True

20

Maximal power can be produced at about 50% of velocity capability

True

21

Total power output depends on the quantity of power and the time it is sustained

True

22

Torque

The turning effect created by a force about an axis

23

Muscular force moves limbs around their respective axis of rotation as defined by the joint

True

24

The further the resistance is held from the body, the longer the resistance arm, and the greater the magnitude of torque required to move the load

True

25

Resistance arm

Distance between the fulcrum and the resistance point

26

The more torque experienced during exercise, the greater the difficulty of the movement, even when the weight remains constant

True

27

Center of gravity (COG)

Point where the mass of an object is equally balanced

28

Changes in the COG may cause the body to work harder to establish static equilibrium, dynamic balance and/or stability

True

29

Kinetic chain

A group of body segments that are connected by joints and operate together to provide a wide range of motion for a limb

30

External force energy must be transferred across the kinetic chain to effectively join with internal forces

True

31

Energy leaked due to unstable segments will limit internal force application, reducing external force

True

32

Stability is achieved with

Mass of the object, height of the GOC, line of gravitational pull and base of support

33

The wider the base of support, the more stable an object will become (e.g., brick lying flat vs. on its side)

True

34

Enhanced stability is achieved when the width of the base of support is widest and in-line with the direction of the resistance

True

35

Angular momentum is commonly employed during exercise when excessive resistance is used

True

36

Most often generated from hip extension of Flexion to increase total force output

True

37

Prime movers preform less work and experience reduced training stress compared to the employment proper lifting technique

True

38

The body's production of angular momentum from rotational inertia requires a force proportionate to the angular momentum to stop the movement

True

39

Prime antagonists that cannot manage the declaration requirements employ assistive musculature throughout the kinetic chain to help slow the movement

True

40

Antagonist

Told of a muscle whose torque opposes a preformed action

41

Agonist

Role of a muscle whose torque aids a preformed action; referred to as the prime mover

42

When the agonist muscle group surpasses the antagonist muscle group's strength balance requirements, injuries will occur

True

43

Strength balance

The force production relationship between an agonist and antagonist muscle or group of muscles acting on a joint