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Flashcards in Modalities Deck (41)
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1
Q

What are the contraindications to thermal modalities?

A
  1. Cancer in the area
  2. active infections
  3. decreased sensation to the area
  4. cognitive deficits to explain sensation
  5. metal implants
  6. undergoing X-ray therapy
  7. ACUTE inflammation, fevers
  8. peripheral vascular disease (impaired circulation)
  9. possibility of clot
  10. active bleeding
2
Q

What are the contraindications to ice?

A
  1. angina pectoris or other cardiac dysfunctions
  2. open wounds
  3. arterial insufficiency
  4. cold urticarial
  5. patients with preexisting anesthetic skin or inability to communicate
  6. regenerating peripheral nerves
3
Q

What are the contraindications to e-stim?

A
  1. wounds with osteomyelitis
  2. application over topical agents containing heavy metal ions
  3. systemic infections
  4. pts wearing demand-inhibited cardiac pacemakers
  5. stimulation directly over superficial metal implants
  6. active bleeding in the area to be treated
  7. malignancies in the area to be treated
  8. very disoriented patients
  9. over a gravid uterus
4
Q

What are the contraindications to TENS?

A
  1. demand-inhibited cardiac pacemaker
  2. pregnancy
  3. over carotid sinus, laryngeal or pharyngeal muscles, sensitive eye areas, or mucosal membranes
  4. while operating hazardous machinery
  5. pain or condition of unknown etiology
5
Q

What are contraindications for US?

A
  1. application over anesthetic area
  2. impaired arterial circulation
  3. hemorrhage
  4. over eyes
  5. over reproductive organs, pregnant uterus
  6. cancer- local exposure
  7. over spinal cord and brain
  8. in presence of infection
  9. over carotid minus or cervical ganglia or over a pacemaker
  10. thrombophlebitis
  11. growing epiphyseal plates
6
Q

How does high frequency TENS decrease pain?

A
  • gate theory
  • TENS excites A beta fibers, which excite inhibitory interneurons, which releases enkephalin; inhibits transmission of pain of presynaptic release from a delta and C fibers
7
Q

How does low frequency decrease pain?

A
  • stimulates the pituitary gland through the reticular formation causing the release of endogenous endorphins to control pain
  • longer lasting pain control
8
Q

When would you use 3.3MHz? what is the minimal intensity for a thermal effect?

A
  1. 3 MHz is superficial target tissue (<1 inch below the surface)
    - minimal dosing is .5 W/cm2
9
Q

When would you use 1MHz? what is the minimal intensity for a thermal effect?

A

for a deeper target tissue
- 1-2” below surface = minimal dosing is 1 W/cm2
= >2” below surface = minimal dosing is 1.5 - 2 W/cm2

10
Q

The intensity of radiation absorbed is maximum when there is no angle between the surface & the source, but as the angle between the radiation (beam) and surface is increased, less energy is absorbed. The amount of energy absorbed varies as a Cosine function of the angle between the surface and the source.

A

Cosine law

11
Q

The intensity of energy received on a surface is inversely proportional to the square of the distance from the source; the greater the distance = the lower the intesity

A

inverse square law

12
Q

US waves are _________ waves created by a crystal that vibrates at a frequency of 0.8 MHz to 1.0 MHz and 3 MHz

A

linear compression

13
Q

The crystal located in the US head vibrates by _______ in response to an alternating current creating US at the ______ of the applied current

A

expanding and contracting; frequency

14
Q

the changing of electrical energy to mechanical energy; The applied voltage causes compression of the crystal in US head; alternating current compresses and expands the crystal creating the linear compression waves

A

Reverse Piezoelectric Effect

- electrical energy converted to mechanical

15
Q

Movement of molecules are perpendicular to the direction of sound wave propagation

A

Transverse wave

  • only occurs in solids
  • occurs in bones
16
Q

Movement of molecules are parallel to the direction of sound wave propagation

A

Longitudinal wave

  • occur in liquids and solids
  • occur in soft-tissue and bone!
17
Q

Resistance to sound waves

A

acoustic impedance

18
Q

What reflects sound waves and presents the most acoustic impedance?

A

Air

19
Q

What is needed to transmit mechanical sound waves from the US crystal (head) into the body tissues?

A

Denser mediums

  • water, US gel, mineral oil, lotions
  • lotions and creams contain more air bubbles causing acoustic impedance
20
Q

Increased concentration of molecules and increased pressure in regions called

A

condensations

- areas of high pressure (molecule compression)

21
Q

Decreased concentration of molecules and decreased pressure in alternating regions called

A

rarefactions

  • areas of low pressure (molecule expansion)
  • This is where heat is produced!!
22
Q

When do molecules move?

A

during the rarefaction phase

23
Q

When is heat produced in ultrasound?

A

When molecules encounter attenuation to movement (moving molecule bumps into dense tissue creating friction, causing heating of tissue)

  • the more attenuation, the more heat produced!
  • more amount of protein (collagen) in tissue = more attenuation
  • less amount of water = more attenuation
24
Q

average intensity of all regions of the sound beam, and is most affected by the Spatial Peak Intensity.

A

Spatial average intensity

25
Q

Spatial peak intensity / spatial average intensity

A

beam nonuniformity ration (BNR)

  • usually 6:1
  • depends on US head
  • if SPI gets larger than BNR, it could be a danger to your patient
26
Q

What does the intensity setting on the US machine represent?

A
  • with continuous = Spatial average intesnity

- with pulsed = temporal peak intensity

27
Q

What does BNR mean clinically?

A
  • the BNR represents where the treatment field is highest
  • for example, BNR is 5:1 - the average intensity to treatment area will be 1 W/cm2, but at the concentrated area (in the center of the beam), the intensity of the wave is actually 5 W/cm2
  • this is why the ultrasound head must be moved around with adequate speed (4cm/sec) to avoid hot spots
28
Q

setting on US machine during continuous wave US. Represents the average intensity of the sound beam and is sensitive to all high & low strength regions, but is most sensitive to the Spatial Peak Intensity

A

Spatial average intensity

29
Q

The greatest intensity anywhere in the within the US beam

A

spatial peak intensity

30
Q

method of altering the strength of the US beam by “turning the sound wave “on & off” or pulsing the sound wave. When the sound is “off” the intensity is zero; and when the sound is “on” or during the pulse, the intensity is maximum

A

Pulsed ultrasound

31
Q

The US machine setting (W/cm2) during pulsed ultrasound. It does not equal the actual intensity of ultrasound energy received by the patient during pulsed ultrasound

A

Temporal peak intensity

32
Q

the average ultrasound intensity received by the patient over the time of the pulse; the actual ultrasound energy received by the patient during pulse ultrasound

A

Temporal average intensity

- To determine the Temporal Average Intensity you must understand the Duty Cycle of Pulsed Ultrasound

33
Q

How does US decrease muscle spasms caused by musculoskeletal injury?

A
  1. US decreases the frequency of discharge of Type II muscle spindle afferents
  2. US increases the frequency of discharge of Type Ib GTO afferents (inhibits α-motoneurons)
34
Q

What is the effects of US on collagen?

A
  1. US selectively raises the temperatures of joint capsules and scar tissue because the high collagen content and low water content of these tissues.
  2. With the temperatures raised to the therapeutic range, US increases the extensibility of these tissues.
35
Q

What is the therapeutic heating range?

A

41 - 45 degrees C

36
Q

What kind of US would you use for acute and subacute inflammation?

A

pulsed US

37
Q

what does the cosine and inverse square laws apply to?

A
  1. Microwave Radiation
  2. Infrared Radiation
  3. Ultraviolet Radiation
38
Q

How is beat frequency derived from carrier frequency?

A

The two circuits need to be on slightly different carrier frequencies. For example:

  • Circuit 1 is set to 4000 Hz
  • Circuit 2 is set to 4100 Hz
  • the adding of the two waves (in the tissue) forms a beat with times of amplitude peaks and times of no amplitude
39
Q

What would you set the TENS machine to if you wanted longer pain relief?

A
  • beat frequency of 1-10 Hz

- amplitude adjusted to muscle contraction

40
Q

What would you set the TENS machine to if you wanted pain relief and the pt couldn’t stand a intensity of muscle contraction?

A
  • beat frequency of 50-150 Hz

- amplitude adjusted to sensation only

41
Q

What is the difference between a lower and higher carrier frequency?

A
  • lower = greater cycle duration; reduces accommodation but is less comfortable
  • higher = reduces skin resistance and in theory is more comfortable to patient