Chapter 7: Biomechanics

Question 1

What are the anatomical planes of movement?

Answer 1

sagittal
frontal
transverse

Question 2

What plane divides the body into right and left segments?

Answer 2

Sagittal plane

Question 3

What’s an example of the sagittal plane?

Answer 3

Flexion and extension

Question 4

What plane separates the body into ventral (anterior) and dorsal (posterior) segments?

Answer 4

Frontal (coronal) plane

Question 5

What plane separates the body into superior and inferior segments?

Answer 5

Transverse (axial) plane

Question 6

What’s an example of the frontal (coronal) plane?

Answer 6

abduction, adduction, and lateral

Question 7

What’s an example of the transverse plane?

Answer 7

Rotational movements

Question 8

What are the 3 primary joints forming the shoulder girdle?

Answer 8

The glenohumeral (GH) joint

The acromioclavicular (AC) joint

The sternoclavicular (SC) joint

Question 9

The study of mechanical laws related to movement or structure is called . . .

Answer 9

Biomechanics

Question 10

What are the two main types of biomechanic systems?

Answer 10

Dynamic and static

Question 11

What do we call systems in motion with acceleration

that create uneven forces acting on the body?

Answer 11

Dynamic systems

Question 12

What are the characteristics of static systems?

Answer 12

At rest
No acceleration
Still with no motion
Constant motion with no acceleration

Question 13

What is velocity?

Answer 13

The direction and rate of displacement

Question 14

What’s the difference between kinematics and kinetics?

Answer 14

Kinematics describes motions of the body

Kinetics describes the forces acting on a body in motion

Question 15

What’s the most common mechanical machine with the body? What does it consist of?

Answer 15

Lever systems, which consist of a bar and an axis

Question 16

How do levers function?

Answer 16

Levers rotate around an axis as a result of force applied to move weight or applied against resistance

Question 17

What’s another name for an axis and force?

Answer 17

Fulcrum

Load or effort

Question 18

The bones are the . . .
The joints are the . . .
The muscles contract to . . .

Answer 18

levers
axes
apply force

Question 19

What’s the common lever?

Answer 19

Third-class

Question 20

What is torque?

Answer 20

Turning effect of force applied to the various levers to create movement

Question 21

What is eccentric force?

Answer 21

Force applied in a direction not in line with the center of rotation when an axis is fixed, necessary for rotation

Question 22

How is torque determined?

Answer 22

Force x length x distance (fulcrum and the force)

Question 23

How does torque affect human movement?

Answer 23

The length of the lever determines the amount of velocity

For example, a tennis player can strike a tennis ball harder and with more velocity with a straight arm than with a bent elbow

Question 24

When is a shorter level preferred?

Answer 24

When speed is desired instead of velocity

Question 25

What mechanisms enhance range of motion and speed or change the direction of movement?

Answer 25

Wheels, axles, and pulleys

Question 26

What are the laws of motion?

Answer 26

Motion of the human body is always initiated by a muscular contraction These contractions initiate and propagate movement and are the source of force

Question 27

What are two types of motion for human movement

Answer 27

Linear: Movement along a line (straight or curved) Angular: Rotation around an axis

Question 28

What law of motion describes the distance an object is displaced from its starting point?

Answer 28

Displacement

Question 29

What law of motion refers to the total or sum of the length of travel?

Answer 29

Distance

Question 30

What law of motion refers to the change in location of a rotating object?

Answer 30

Angular displacement

Question 31

What law of motion describes the distance an object moves in a straight line

Answer 31

Linear displacement

Question 32

The biomechanical system maintains the current motion whether the body or a segment is moving or at rest. What's the only thing that can change the status of movement?

Answer 32

force via muscular contraction

Question 33

The change of acceleration is directly proportional to the ___ causing it and ____ proportional to the mass of the body

Answer 33

Force | Inversely

Question 34

What provides the reactionary force in opposition to the force of the human body?

Answer 34

Surface, aka friction

Question 35

What is the force created by the resistance between two surfaces of two objects moving across one another?

Answer 35

Friction

Question 36

What are the 3 types of friction?

Answer 36

Static friction: The friction between two objects not moving Kinetic friction: The friction between two objects moving across one another Rolling friction: The friction when one object rolls across a surface

Question 37

What is constantly challenged in human movement?

Answer 37

balance, equilibrium, and stability

Question 38

What is balance?

Answer 38

The ability to control equilibrium

Question 39

What is equilibrium?

Answer 39

A state of no acceleration with the body at rest

Question 40

What is stability?

Answer 40

Resisting changes to the body’s acceleration or equilibrium

Question 41

What is the state in which all objects desire to be?

Answer 41

Equilibrium

Question 42

When is it possible to achieve static equilibrium?

Answer 42

When the body is at rest

Question 43

What is the state when the body is moving at a steady and unchanging speed or direction?

Answer 43

Dynamic equilibrium

Question 44

When is stability maximized?

Answer 44

When the center of gravity can be determined and, if necessary, shifted

Question 45

What is the point at which both body mass and weight are equally distributed?

Answer 45

Center of gravity

Question 46

Momentum =

Answer 46

Mass x velocity

Question 47

What are the two types of loads?

Answer 47

external or internal forces

Question 48

What gives rise to internal loads?

Answer 48

Muscle contraction

Question 49

What are the 5 types of stress from mechanical loading?

Answer 49

``` Tension: stretching or strain Compression: reducing in volume and increasing in pressure Bending: shaping into a curve or angle Torsion: twisting Shearing: cutting or breaking ```

Question 50

What's the best way to avoid deformations on the body from mechanical stress?

Answer 50

Absorbing force over a larger part of the body over time

Question 51

A joint has only the ability to . . .

Answer 51

Rotate

Question 52

What is always opposite of the direction of rotation?

Answer 52

Direction of resistance

Question 53

What is flexion?

Answer 53

Movement decreasing the angle between two body parts

Question 54

What is extension?

Answer 54

Movement increasing the angle between two body parts

Question 55

What is abduction?

Answer 55

Movement away from the midline

Question 56

What is adduction?

Answer 56

Movement toward the midline

Question 57

What is medial rotation?

Answer 57

Rotational movement toward the midline

Question 58

What is lateral rotation?

Answer 58

Rotational movement away from the midline

Question 59

What is elevation?

Answer 59

Movement in a superior direction

Question 60

What is depression?

Answer 60

Movement in an inferior direction

Question 61

What is a triplanar motion occurring from dorsiflexion, eversion, and abduction?

Answer 61

Pronation

Question 62

What is the combined motion of plantar flexion, inversion, and adduction?

Answer 62

Supination

Question 63

What causes a bone to rotate around its axis?

Answer 63

The contraction of muscles, which creates an eccentric force

Question 64

What are the following? Motion of the human body is always initiated by a muscular contraction These contractions initiate and propagate movement and are the source of force

Answer 64

Laws of motion