Modalities

Question 1

What is the physical stress theory?

Answer 1

none/low = cell death
low = atrophy
normal = maintenance
moderate = hypertrophy
high = injury
extreme = cell death

Question 2

What is the physical stress equation?

Answer 2

exposure (magnitude) + duration + direction = stress placed on tissues

Question 3

What is a therapeutic modality?

Answer 3

A stress placed upon the body to elicit an involuntary physiological response (correct form of energy + proper stage of healing = regeneration)

Question 4

What occurs during primary trauma? What are you trying to avoid? What are you trying to elicit?

Answer 4

Primary trauma = cell death, inflammation & hemorrhage edema
Avoid = hypoxia, blood flow congestion, enzymatic injury, pain, spasm, atrophy
elicit = phagocytosis, blood clotting, revascularization, wound contraction, wound healing

Question 5

When does secondary injury start?

Answer 5

30 mins after primary injury

Question 6

What is the difference between swelling and edema?

Answer 6

swelling = fluid build up & increased capillary permeability (fluid leaves capillaries and enters tissue)
edema = fluid and protein build up in interstitial space (can obstruct venous and lymphatic return)

Question 7

What layers must ice go through?

Answer 7

skin, adipose tissue, fascia, muscle

Question 8

What causes a greater depth of cryo penetration?

Answer 8

longer duration and larger treatment area

Question 9

How does re-warming occur?

Answer 9

Deeper tissues are re-warmed by blood (increased cell metabolism) and skin temp is increased by blood & air

Question 10

How long does intramuscular temperatures continue to decrease after removal of a cold modality? How long does intramuscular temp remain elevated after a heat modality?

Answer 10

30 mins for both

Question 11

A 10 degree temp decrease of the skin causes a ___ degree temp decrease at a joint?

Answer 11

6.5 degrees

Question 12

At what temperatures do certain events happen during cryotherapy (decreased blood flow, decreased cell metabolism etc.)?

Answer 12

• BF decreases instantly and levels out at 13 mins
• CSA of lymph vessels decrease at 15 degrees C
• Cell metabolism decreases at 10-15 degrees C
• Nerve changes occur at a skin temp of 5 degrees C
• P decreases and numbness occurs at 14.4 degrees C and P returns at 15.6 degrees C (approx 18-21 mins of ice application)

Question 13

Does ice affect proprioception? If yes, for how long?

Answer 13

Yes, it affects proprioception for 5-10 mins after removal (decreased nerve conduction velocity and decreased perception of P)

Question 14

What injuries could result from cold and compression application?

Answer 14

frostbite or cold-induced neuropathy

Question 15

How does cold produce its effects physiologically (decreased P, edema formation etc.)?

Answer 15

blood = vasoconstriction, increased blood viscosity, decreased blood flow
edema = decreased cell metabolism, decreased secondary hypoxic injury (requires compression & elevation to remove edema)
pain = decreased nerve conduction velocity, decreased inflam/swelling (removes chemical and metabolic P triggers)
muscle spasm = decreased stretch reflex, decreased sensitivity of muscle spindles, decreased threshold of afferent nerve endings

Question 16

How much does cold slow down a motor vs sensory nerve?

Answer 16

motor = 1.5m/sec
sensory = 2.6m/sec
(1 degree C intramuscular drop)

Question 17

What is the law of Grotthus-Draper?

Answer 17

If energy is absorbed by one tissue layer it can’t be transmitted to deeper layers

Question 18

What is Fouriers law?

Answer 18

The greater the temperature difference the faster the exchange of energy

Question 19

Explain and provide an example of conduction, convection, conversion, radiation and evaporation

Answer 19

• conduction - transfer of heat by touching of two surfaces ex. ice pack
• convection - transfer of heat through the use of a medium (air/water) ex. whirlpool
• conversion - transfer of heat by changing one form of energy to another ex. ultrasound
• radiation - transfer of heat without the use of a medium ex. laser
• evaporation - heat is absorbed as the liquid turns into a gas ex. vapocoolant spray

Question 20

What is the temperature for cold modalities versus thermal modalities?

Answer 20

cold = 10-18 degrees C
heat = 40-45 degrees C

Question 21

Which penetrates deeper and lasts longer, superficial cold or heat?

Answer 21

superficial cold

Question 22

How much does exercise increase body temp and at what depth?

Answer 22

2.2 degrees C at 5cm

Question 23

By what 4 methods is heat produced?

Answer 23

1. transfer of thermal energy
2. chemical action associated with cell metabolism
3. mechanical action (therapeutic U/S)
4. electrical or magnetic currents (diathermy)

Question 24

When should you use cold versus heat?

Answer 24

cold = acute inflammation, before ROM exercises, after activity to decrease cell metabolism
heat = subacute/chronic inflammation, promote venous drainage, encourage tissue healing, reduce edema/ecchymosis, improve ROM before activity

*Patient preference

Question 25

What is the Q10 effect?

Answer 25

for every 10 degree C increase in temp, cell metabolism increases by 2-3x

Question 26

What increases BF more, moist heat or dry heat?

Answer 26

``` moist heat (386% increase) dry heat (282% increase) ```

Question 27

What is required to increase tissue elasticity?

Answer 27

increase tissue temp to 40-45 degrees C for 5 mins then stretch the tissue

Question 28

What is rebound vasoconstriction?

Answer 28

after 20 mins of heating the vessels with automatically constrict to protect the deeper structures

Question 29

How does adipose tissue affect heating/cooling?

Answer 29

Need to increase duration 20mm or less = 25 mins 20-30mm = 45 mins 30-40mm = 60 mins

Question 30

What is inside an ultrasound head and how does it create heat?

Answer 30

piezoelectric crystal that expands and contracts (+ve and -ve electric charges)

Question 31

What is the difference between longitudinal and transvers waves?

Answer 31

``` longitudinal = molecules are displaced parallel to direction of sound, travels through solid and liquid media (soft tissue) transverse = molecules are displaced perpendicular to sound waves, can only travel through solids (occurs when sound strikes bone) ```

Question 32

Explain reflection, refraction and absorption

Answer 32

1. reflection - beam goes in opposite direction (at an angle) when it strikes a surface 2. refraction - beam continues in the same direction but is bent (speeds up if dense to less dense and slows down if less dense to dense) 3. absorption - energy is converted to heat in a layer and cannot move to deeper layers

Question 33

What is the effective radiating area (ERA)?

Answer 33

Small portion of transducer surface that produces ultrasonic energy

Question 34

What are the differences between 1mhz and 3 mhz?

Answer 34

``` 1mhz = low frequency, divergent, 5cm deep, slower absorption, retains heat 2x longer 3mhz = higher frequency, collimating, 2-3cm deep, faster absorption (3x), heat leaves faster ```

Question 35

What is the beam nonuniformity ratio (BNR)?

Answer 35

ratio of the highest intensity within the beam with the average intensity (8:1 is unsafe)

Question 36

What components of the body are highly reflective?

Answer 36

Bone MTJ Intermuscular interfaces Air

Question 37

What is cavitation, acoustical streaming and microstreaming?

Answer 37

Occur to produce non-thermal U/S effects. 1.cavitation = ultrasound produces pressure in tissue fluids which creates gas bubbles that expand and contract 2.acoustical streaming = bulk flow of fluids in one direction 3. microstreaming = fluids move in one direction across a boundary and can change cell structure/function cavitation + acoustical streaming = microstreaming (increases cell membrane permeability)

Question 38

What is the difference between direct current, alternating current and pulse current with examples

Answer 38

DC - uninterrupted flow of electrons from cathode to anode ex. iontophoresis AC - uninterrupted flow of electrons is bidirectional (no true +ve or -ve) ex. IFC/TENS Pulsed - flow of electrons is interrupted by periods of no electron flow (monophasic or biphasic) ex. NMES/Russian

Question 39

What 4 factors affect current flow (resistance to flow)?

Answer 39

1. Conductor material (blood & nerves are better than skin and bone) 2. Length of circuit (shorter = less resistance) 3. CSA of circuit (larger CSA = less resistance) 4. Temperature of skin (warmer temp = less resistance)

Question 40

What tissues are better suited to small pads vs large pads?

Answer 40

small pads = superficial nerves and decreased adipose tissue | large pads = deep nerves and increased adipose tissue

Question 41

What 3 things can change how a nerve responds to electrical stim?

Answer 41

1. Depth of nerve 2. Diameter of nerve 3. Phase duration of current

Question 42

Name the nerves from superficial to deep

Answer 42

sensory nerves motor nerves pain fibres muscle fibres

Question 43

Why do motor nerves fire before pain fibres?

Answer 43

because P fibres have a smaller diameter so they take longer to depolarize

Question 44

What is the difference between a normal muscle contraction and an electrically induced muscle contraction?

Answer 44

normal contraction = - small --> large fibres - contractions and recruitment are asynchronous to decrease fatigue - GTO protect muscle from tension - slow to fatigue Electrically induced = - large -->small fibres - contraction and recruitment are synchronous - GTO can not protect against tension - quick to fatigue

Question 45

What pps is required to reach tetany?

Answer 45

30-40pps

Question 46

Can you get DOMS from electrical stim?

Answer 46

Yes

Question 47

Can you increase strength on the opposite side of electrical stim? If yes, by how much? Why would you do this?

Answer 47

yes, by 10% | to delay atrophy or assist in re-education

Question 48

What are the goals of electrical stim with parameters?

Answer 48

1. Decrease Edema = - 30-50 pps - electrode proximal to edema - 5-10s on 5-10s off - ramp = 0.5s- none - elevate body part and relax - 10-20 mins daily 2. Muscle spasm - 50-70pps - on muscle group in spasm - 10s on 10s off - 1-2s ramp - pt tries to relax - 10-20 mins daily 3. Strength/re-ed - 50-70pps - electrode on muscle - 10:50 (re-ed), 10:30 (strength) - 2-3s ramp - contract with on cycle - 10-20 mins daily

Question 49

What 4 things/domains contribute to how we interpret pain?

Answer 49

1. evaluative- previous P experience 2. sensory - nature of P stimulus 3. affective - mental/emotional state 4. misc - how everything combines into a feeling

Question 50

How fast does a nerve fire?

Answer 50

33mph

Question 51

What is the gate control theory?

Answer 51

Block painful stimulus from reaching the brain = pain relief - stimulate A-beta fibres to reach the spinal cord first (only one sensation at a time can go up) - A-beta = larger fibre, stimulates the SG and prevent P signal from going up

Question 52

What is the opiate theory?

Answer 52

Allow painful stimulus to reach brain so that the body will release endogenous opiates A-delta = large pain fibre (sharp/stinging) C-fibres = small pain fibre (dull/aching) Small fibres inhibit the SG and allow the pain signal to go up (releases enkephalin from pituitary to decrease P)

Question 53

What else besides P relief can IFC do in a meh way?

Answer 53

edema reduction, decrease muscle spasm and bone stimulation

Question 54

What are contras for cold application?

Answer 54

``` open wounds sensory deficit cold allergy cold sensitivity PVD thrombosis advanced diabetes Raynaud's Lupus Hemogolbinemia cold-induced miocardial ischemia ```

Question 55

What are contras for heat application?

Answer 55

``` acute inflammation sensory deficit infection cancer PVD advanced arthritis thrombophlebitis impaired circulation poor thermal regulation DVT Pregnancy ```

Question 56

What are contras for U/S application?

Answer 56

``` Same as heat for thermal, as well as unstable fracture pacemaker metal implants joint replacements organs breast implants eyes, heart, skull, carotid sinus, genitals ```

Question 57

What are contras for electrical stim application?

Answer 57

``` seizures metal implants psychological impairments pacemaker sensory deficits infection blood clots pregnancy cancer unstable fracture arterial disease cardiac disability ```