Chapter 3: Energy

Question 1

Electrophysical Agent

Answer 1

• for of therapy used in rehabilitation that changes tissue through water, temp, sound, electricity. Include TENS, ultrasound, whirlpool, hot and cold packs, and other modalities
• alternate: application or removal of energy from biological tissue in order to stimulate that tissue to perform its normal function

Question 2

TENS

Answer 2

transcutaneous electrical nerve stimulation

Question 3

energy

Answer 3

• capacity to do work. manifested as motion (kinetic), potential (potential energy), light, heat, ionizing radiation, sound
• neither created nor destroyed

Question 4

radiant energy

Answer 4

• process by which energy of various forms travels through space
• everything above absolute zero (-273C) emit radiant energy
• occurs when sufficient electrical or chemical force is applied to an object
• explained by quantum and electromagnetic wave theory

Question 5

radiant energy cont.

Answer 5

• thought of as a packet of energy carried along by propagating waves
• constant velocity (3x10^8 m/sec)
• includes radio waves, microwaves, infrared waves, visible light waves, ultraviolet waves, x-rays, gamma rays, and cosmic rays

Question 6

quantum theory

Answer 6

• packet of energy (indivisible)-photon
• produced by high velocity electronic or molecular motion or transformed kinetic energy released when molecules collide
• E(quantum)=H(Planck’s constant) x f(frequency)
• the higher the frequency, the higher the photon energy-> potentially destructive

Question 7

electromagnetic wave theory

Answer 7

• energy is transmitted by oscillatory motion in the form of electromagnetic waves
• composed of perpendicularly oriented fields of electric and magnetic composition that vary over time
• can propagate without the need of a medium (travel through vacuum, like space)
• velocity=wavelengthxfrequency(f)
• shorter the wavelength, the higher the frequency

Question 8

radiant energy cont.

Answer 8

• quantum theory states that if frequency (f) is low, energy (E) must be low
• electromagnetic theory states that if frequency (f) is low, wavelength is long (high)
• thus, therapeutic modalities at low electromagnetic frequencies have relatively long wavelengths and low amounts of energy, safe to apply to human system

Question 9

low frequency electromagnetic radiation

Answer 9

• ELF waves
• shortwaves
• microwaves
• IR radiation
• visible light
• ultraviolet A and B radiation
• all non-ionizing (cannot break molecular bonds or produce ions)

Question 10

high frequency EMR

Answer 10

• x-rays
• gamma rays
• are ionizing (can inhibit cell division, break molecular bonds and form ions)

Question 11

arndt-schultz principle

Answer 11

• energy absorbed must be sufficient so as to stimulate the absorbing tissues
• -ex: e-stim for muscle contraction. the current intensity must be strong enough to facilitate depolarization of the nerve
• -ex: heat to increase tissue elongation. must be intense enough to increase viscoelastic properties of tissue
• too much energy absorbed may impair normal function of the tissues

Question 12

law of Grotthus-Draper

Answer 12

• if energy is not absorbed by the superficial tissue, then it will penetrate to deeper tisues
• ex: 1MHz, US will be more efficient in treating deeper tissues than 3 MHz, US

Question 13

cosine law

Answer 13

• maximum amount of absorption of radiant energy occurs when the source is at righ angles to the absorbing surface
• energy absorbed=energy available x cos theta

Question 14

inverse square law

Answer 14

-intensity of the radiation striking the surface varies inversely with the square of the distance from the source

Question 15

bunsen roscoe law of reciprocity

Answer 15

• intensity and duration of the dose of radiant energy are inversely proportional
• energy (E)=intensity (I) x Time (T)

Question 16

how do the laws work

Answer 16

• to increase the amount of energy absorbed by the patient:
• increase treatment time
• increase treatment intensity
• lessen the distance of the source of energy to the pt
• make the source of energy more perp. to absorbing surface

Question 17

electromagnetic modalities

Answer 17

• e-stim
• biofeedback
• iontophoresis
• shortwave and microwave diathermy
• infrared
• UV
• low-power laser

Question 18

acoustic spectrum

Answer 18

• range of frequencies and wavelengths of sound waves
• audible sound: frequencies between 16 and 20 KHz
• ultrasound-frequencies above 20KHz
• therapeutic ranges-.75 and 3.3 MHz

Question 19

acoustic modalities

Answer 19

• therapeutic ultrasound (above .75 mHZ-3.3MHz)
• phophoresis
• ultrasound is generally thought of as a mechanical modality

Question 20

mechanical modalities: mechanical traction

Answer 20

• cervical

- lumbar

Question 21

mechanical modalities: compression

Answer 21

• external pumps

- elastic bandages

Question 22

physical agent categories

Answer 22

• thermal
• mechanical
• electromagnetic

Question 23

thermal

Answer 23

-deep heating
-superficial heating
-cooling
CLINICAL EXAMPLES
-diatherrmy
-hot pack
-ice massage

Question 24

mechanical

Answer 24

traction
compression
water
sound
CLINICAL EXAMPLES
-mechanical
elastic bandage
whirlpool
ultrasound

Question 25

electromagnetic

Answer 25

electric currents
electromagnetic fields
CLINICAL EXAMPLES
interferential
ultraviolet

Question 26

precautions and contraindications

Answer 26

• precaution: conditions where a particular physical agent should be applied with care or limitations
• contraindication: condidtions where the application of a particular agent is unsafe or undesirable

Question 27

general contraindications and precautions

Answer 27

• pregnancy
• malignancy
• pacemaker
• impaired sensation
• impaired mental status