chapter 1

Question 1

What branch of mechanics describes motions of the body

Answer 1

kinematics

Question 2

The center of mass of the human body tends to move in what line

Answer 2

curvilinear

Question 3

movement of the body can be described as which two ways

Answer 3

active or passive

Question 4

What are the three planes of motion and how do they divide the body

Answer 4

Sagittal: Left and right sides
Frontal (coronal): anterior and posterior
Transverse (horizontal): superior and inferior

Question 5

Osteokinematics describes what

Answer 5

motion of the bones relative to the three planes

Question 6

The number of independent directions of movement at a joint is referred to as what?

Answer 6

Degrees of freedom

Question 7

The sagittal plane allows what type(s) of joint movement(s)?

Answer 7

flexion and extension

Forward/backward bending

Question 8

The frontal plane allows what type(s) of joint movement(s)?

Answer 8

ABduction and ADduction
Lateral flexion
Ulnar and radial deviation
eversion and inversion

Question 9

The transverse plane allows what type(s) of joint movement(s)?

Answer 9

Internal and External rotation

Axial Rotation

Question 10

What part of the joint has zero body motion?

Answer 10

axis of rotation

Question 11

Accessory motions are defined as

Answer 11

slight passive translations that occur in most joints

Question 12

What are the two perspectives that movement can be described as?

Answer 12

Proximal segment can rotate against a fixed distal segment (closed kinetic chain)
Distal segment can rotate against a fixed proximal segment (open kinetic chain)

Question 13

Arthrokinematics describes what

Answer 13

motion that occurs between the articular surfaces of joints

Question 14

What are the three fundamental movements that can exist between joint surfaces?

Answer 14

Roll, slide, and spin

Question 15

Describe Roll-and-slide movement

Answer 15

rolling of its articular surface against another bone’s articular surface and coupled with the sliding of articular surface

Question 16

describe the spin movement

Answer 16

spinning of its articular surface against the articular surface of another bone

Question 17

Describe the convex-on-concave movement

Answer 17

convex segment rolls and slides in opposite directions

Question 18

Describe the concave-on-convex movement

Answer 18

concave segment rolls and slides in similar directions

Question 19

The position of maximal congruency is referred to as:

Answer 19

the joint’s close-packed positions

Question 20

Accessory motions are _______ in a joint’s close-packed position?

Answer 20

minimal

Question 21

Open(loose)-packed positions are considered to be

Answer 21

all positions other than close-packed

Question 22

Accessory motions are _______ in open-packed position

Answer 22

maximal

Question 23

Kinetics describes what branch of mechanics

Answer 23

the effect of forces on the body

Question 24

When is the force zero

Answer 24

when the acceleration of the mass is zero

Question 25

What forces are most frequently applied to the musculoskeletal system?

Answer 25

tension, compression, bending, shear, torsion, combo loading

Question 26

the stress/strain curve shows what?

Answer 26

the amount of force required to deform an excised tissue

Question 27

Viscoelasticity

Answer 27

factor of time, causing the stress/strain curve to change

Question 28

creep

Answer 28

long, constant stress | i.e. your vertebral discs over the course of day, hence why you are shorter in the evening.

Question 29

Forces produced from structures within the body are referred to as:

Answer 29

internal forces

Question 30

Active internal forces are produced by what?

Answer 30

muscles under volitional control

Question 31

passive internal forces are produced by what?

Answer 31

gravity, or tension in stretched connective tissues

Question 32

What forces occur outside of the body?

Answer 32

External forces

Question 33

Line-of-force or line-of-gravity

Answer 33

direction of a muscle force and the direction of gravity

Question 34

angle of insertion

Answer 34

angle formed between the tendon of a muscle and the long axis of the bone to which it inserts

Question 35

Gravity acts on what part of the body segment

Answer 35

center of mass

Question 36

Joint reaction force

Answer 36

force through the center of the joint, produced between surfaces of a joint

Question 37

static linear equilibrium

Answer 37

where no movement occurs due to equal forces

Question 38

forces that act at a distance from the axis of rotation produce what?

Answer 38

a potential rotation of the joint

Question 39

moment arm

Answer 39

distance the force is acting, that causes the torque

Question 40

When internal moment equals the external moment, what happens?

Answer 40

no motion or rotation | aka static rotary equilibrium

Question 41

What are the types of muscle activation?

Answer 41

concentric, eccentric, and isometric

Question 42

concentric contraction refers to what?

Answer 42

the shortening of the muscle fibers

Question 43

eccentric contraction refers to what?

Answer 43

the lengthening of muscle fibers

Question 44

isometric contraction refers to what?

Answer 44

the fiber lengths do not change

Question 45

biceps vs. triceps is termed as what?

Answer 45

agonist vs. antagonist

Question 46

gluteus max + hamstrings is termed what?

Answer 46

synergists

Question 47

hip flexors and low back extensor muscles is termed what?

Answer 47

force-couple

Question 48

Force-coupling

Answer 48

what two or more muscles simultaneously produce forces in different linear directions, although the resulting torque act in same rotary direction (ie turning wheel with two hands)

Question 49

how many musculoskeletal levers are there?

Answer 49

three

Question 50

1st class lever

Answer 50

axis of rotation is between opposing forces

Question 51

2nd class lever

Answer 51

axis of rotation is located at one end of the bone, and the internal force (muscle) has greater leverage than the external force

Question 52

3rd class lever

Answer 52

axis of rotation is at one of the bone, and the external force exceeds the internal force

Question 53

what lever is most common

Answer 53

third class

Question 54

what is mechanical advantage (MA)

Answer 54

a ratio of the internal moment arm to the external moment arm (external force to internal force)

Question 55

why must third class levers always have MA<1

Answer 55

The muscle force must produce a force that is much greater than the opposing external force