kinematics, kinetics, muscle performance and function and joints test questions

Question 0

what are the components of kinematics?

Answer 0

displacement, velocity and acceleration

Question 1

what is kinematics?

Answer 1

branch of mechanics that describes motion of objects

Question 2

what is displacement?

Answer 2

change in position of an object

Question 3

what is velocity?

Answer 3

• Rate at which an object moves in a given direction

- Time rate of change of displacement (m/s)

Question 4

what is acceleration?

Answer 4

rate of change of velocity with respect to time

Question 5

what are the two types of motion?

Answer 5

linear (translation) and rotational

Question 6

what is linear motion?

Answer 6

all points move equidistant in the same direction, at the same time (translation)

• occur in a straight line (rectilinear)
• occur in a curvature (curvilinear) (ex. gait)

Question 7

what is rotational motion?

Answer 7

circular motion around a fixed point (angular)

• all points rotate simultaneously
• axis or rotation is the pivot point

Question 8

what is the relationship between linear and rotational motion? what is an example of this?

Answer 8

(1) there is a direct relationship
- most motion involves a combination
(2) glenohumeral joint

Question 9

what is the difference between osteokinematics and arthokinematics?

Answer 9

osteokinematics: includes ROM, Planes of motion, degrees of freedom
arthrokinematics: describes movement of the joint surfaces when a bone moves through a ROM (includes roll, spin and glide)

Question 10

what is joint play?

Answer 10

the passive movement in the form of translation

Question 11

what is the instantaneous center of rotation (ICR)

Answer 11

(1) point about which rotation of an object takes place
- changes throughout the ROM due to the spinning, gliding, and rolling
- the closer the center of rotation is to the joint surface, the more gliding takes place

Question 12

what is the closed packed position (in general)?

Answer 12

joint position in which the ends of the two surfaces are most congruent. Ligaments are on max tension and joint surfaces can not be separated.

Question 13

what is the loose (open) packed position?

Answer 13

position in which a joint has its greatest capacity or volume. Joint ends can easily be separated and ligaments are in a position of laxity.

Question 14

what is kinetics?

Answer 14

the study of motion and the forces that act to produce the motion

Question 15

define mass (m)

Answer 15

the amount of matter that makes up an object (weight includes gravity)

Question 16

define center of mass (CoM)

Answer 16

point about which the body’s mass is evenly distributes (whole body or one segment)

Question 17

define inertia

Answer 17

amount of energy required to alter a body’s velocity

Question 18

define momentum (p)

Answer 18

quantity of motion of an object and is equal to the mass and the velocity (v) p=mv

Question 19

define friction

Answer 19

parallel force that opposes or impedes motion between two contacting bodies

Question 20

what are the different types of forces?

Answer 20

• tensile
• compressive
• shear
• bending
• torsion
• combination

Question 21

example of internal forces within the body

Answer 21

muscle contraction, muscle, ligament stretch, tendon

Question 22

example of external forces acting on the body?

Answer 22

gravity and weight

Question 23

what is torque?

Answer 23

moment force or rotational force

- forces applied at a distance from an axis/joint can produce rotation

Question 24

what is the moment arm?

Answer 24

the distance the force is applied from the axis of rotation

Question 25

What is the concave-convex rule?

Answer 25

When a concave surface moves on a convex surface, roll and glide occur in the same direction.

Question 26

What is the convex on concave rule?

Answer 26

When a convex surface moves on a concave surface, roll and glide occur in the opposite direction.

Question 27

What is a tensile force?

Answer 27

Cool linear forces acting in opposite directions to pull an object apart.
Ex: ligament tear

Question 28

What is a shear force?

Answer 28

Complainer and opposite in direction but not collinear. These forces cause 1 surface of a body to slide past an adjacent surface.
Ex: blister

Question 29

What is a compressive force?

Answer 29

Collinear forces acting in similar directions to push tissues together. Ex: compression fracture, a fall

Question 30

What is static rotary equilibrium?

Answer 30

When internal and external torque are equal.

Question 31

What is the law of inertia?

Answer 31

A body at rest will remain at rest unless acted upon by a resultant force.

Question 32

What is the law of acceleration?

Answer 32

A body subjected to a resultant force will accelerate in the direction of that force, and the magnitude of the acceleration will be proportional to the magnitude of the force.

Question 33

What is the law of action-reaction?

Answer 33

To every action there is an equal and opposite reaction.

Question 34

Class 1 lever

Answer 34

FAR
MA > or <1
Ex: Selenus muscle in neck

Question 35

Class 2 lever

Answer 35

ARF
MA>1
Ex: gastrocnemius/soleus in calf, rising up on toes

Question 36

Class 3 lever

Answer 36

AFR
MA<1
Ex: biceps curl

Question 37

Muscle skeletal properties;

Extensibility

Answer 37

The ability to be stretched or to increase in length. Determined by connective tissues, surrounding muscle.

Question 38

Muscle skeletal properties;

Elasticity

Answer 38

Ability of a tissue to return to its normal resting length after removal of a stretch. Determined by connective tissue about and within the muscle.

Question 39

Muscle skeletal properties;

Irritability

Answer 39

The ability to respond to stimulation from the nervous system. Muscles are very irritable and respond very quickly.

Question 40

Isometric

Answer 40

• Static contraction
• no change in muscle length
• advantageous when joint movement is restricted (post surgical brake)

Question 41

Isotonic

Answer 41

-provides contraction
-change in muscle length occurs
-concentric (shortening)
eccentric (lengthening) greatest force

Question 42

Isokinetic

Answer 42

• concentric or eccentric

- constant velocity is maintained throughout the muscle action

Question 43

Strength

Answer 43

Ability of the muscle to exert a max force or torque at a specified determined velocity.

• absolute
• relative

Question 44

Power

Answer 44

Rate of work per unit time

Power= force x velocity

Question 45

Endurance

Answer 45

Ability to perform low intensity, repetitive, or sustained activities over a. Prolonged period w/o fatigue

Question 46

Factors affecting muscle performance

Answer 46

• neural control and adaptation
• muscle fiber arrangement
• muscle length
• Joint angle
• muscle fiber type
• muscle fiber diameter
• force velocity relationship
• training specificity

Question 47

Clinical measures of muscle performance

Answer 47

• anthropometric (measuring size, weight, properties)
• MMT (tests strength of individual muscles)
• dyamometry (assess pinch and strength)
• isotonic (lifting a fixed max against gravity)

Question 48

List the types of joint receptors found in diarthrosis synovial joints

Answer 48

• ruffini endings (sensitive to stretch at extremes of joint motion)
• Pacinian corpuscles (detect compression, pressure, movement)
• Golgi tendon (detect pressure and forceful motion at extremes)
• unmyelinated free nerve endings (detect noxious and nonnoxious movements and stress)