practical

Question 1

e-stim indications (5)

Answer 1

1. pain
2. muscle weakness
3. edema
4. wound healing
5. diagnostic purposes

Question 2

transcutaneous e-stim works by triggering action potential. to do this we need: (3)

Answer 2

1. sufficient intensity (amplitude)
2. duration (width of pulse)
3. speed of rise

Question 3

order of fibers e-stim works on and why (3)

Answer 3

1. sensory (first tingle) -these have the widest diameter and most mylenated so they are excited quickest
2. motor - this is what you see when u see affected when u see contractions; not actual muscle contractions
   skip over if you put on bony prominence
3. pain (recruited painful nerve fibers)

Question 4

pulse intensity duration curve (2)

Answer 4

1. PW vs. PI

2. shows better discrimination the narrower the pulse width (makes it easer to just trigger sensory)

Question 5

electricity definition

Answer 5

1. electricity is flow of e-

Question 6

amplitude basics (4)

Answer 6

1. amplitude is the # of e-
2. height of pulse
   factors that affect amplitude:
3. voltage - increase in voltage increases potential difference btwn point A & B => driving force for current 4. proportional relationship
4. resistance (ohms)- how well a particular environment conducts the flow (healthy tissue has less resistance than necrotic tissue) 6. inverse relationship

Question 7

3 types of electrical current

Answer 7

1. direct
2. alternating
3. pulsified

Question 8

direct current (2)

Answer 8

1. flows in long pulse (1s or greater) in 1 direction

2. can be very irritating be careful

Question 9

alternating current (3)

Answer 9

1. continous flow in 2 directions (switches polarities)
2. short pulse width (ms)
3. less irritating

Question 10

pulsatile current (3)

Answer 10

1. most common
2. 1 or 2 directions, but not continous monophasic or biphasic (symmetrical or a-symmetrical)
3. narrowest pulse width (microseconds)

Question 11

4 setting on e-stim machine

Answer 11

1. intensity
2. frequency
3. duration
4. modulation

Question 12

pulse intensity

Answer 12

1. height of pulse = amplitude (can change from subsensory -> sensory -> motor)

Question 13

pulse frequency (4- 1= low vs. high frequency)

Answer 13

1. # pulses/ second
2. increase frequency = decrease interpulse interval
3. low frequency = twitching muscle vs. 50pps = tetanic contracion
4. high for wound healing and electro-osmosis because you need polarity*

Question 14

pulse duration (3)

Answer 14

1. pulse width
2. to keep at sensory want low pulse width/ duration
3. for muscles higher b/c want to have as much intensity as possible

Question 15

modulation

Answer 15

1. continuous vs ramp

Question 16

bipolar vs. unipolar

Answer 16

1. bipolar= same size electrodes, used for muscle strengthening
2. unipolar = one much larger than the other, used for wound healing

Question 17

anodes and cathodes (direct current) (4)

Answer 17

1. anodes are (+) and attract (-)ions = cations
   cathodes are (-) and attract (+) ions = anions
2. they are always the same (monophasic) and can causing burning or be irritating because of HCl or NaOH that builds up under skin (NaOH is worse for you, under (+)
3. this doesn't happen with biphasic current b/c change direction
4. doesn't happen with monophasic b/c current is milliseconds

Question 18

gate theory of pain (4)

Answer 18

1. non-noxious A fibers stimulate SG (substantial gelatinous)
2. noxious C fibers don’t stimulate SG (=>SG is inhibited by pain)
3. SG inhibits T cells, which cause pain (this is the “gate)
4. we want to stimulate SG with non-painful stimulus to inhibit pain = comfortable sensory input

Question 19

conventional TENS (transcutaneous electrical neural stimulation)

Answer 19

1. rationale = gate theory of pain
2. PI= low intensity for comfortable sensory
   Waveform : asymmetric biphasic
3. PR = increase frequency as high as possible
4. PW= narrow (50us) to tap into sensory
5. modulations= continuous
6. electrode placement = on or bracket pain, or nerve root
7. rx time= 20m- 24h

Question 20

low frequency TENS

Answer 20

1. rationale= stimulating brain to release endogenous opiates (endorphins)
2. PI= strong sensory, localized motor
3. PR= low frequency
4. PW= wide as possible (more stim at given intensity)
5. modulations= burst to minimize fatigue
6. electrode placement= electrical acupuncture points
7. rx time= 15=45m

Question 21

rationale for NMES (3)

Answer 21

1. better overall recruitment of muscles
2. more selective recruitment of muscles - we volitionally recruit type I muscles, this increases recruitment of type II muscles (fast twitch)
3. synchronous contraction which is more demanding stimulus than our asynchronous normal contractions

Question 22

NMES for muscle strengthening

Answer 22

1. rationale= increase type 2 muscles and increase synchronous contractions
2. PI= strong motor (75% max contraction)
3. PR= tetanizing = 50pps
4. PW= wide
5. modulation= interrupted 1:3 w/ ramped
6. electrode placement: motor point/ muscle belly or peripheral nerve trunk
7. rx time = based on # contractions you want

Question 23

NMES for neuromusclar activation

Answer 23

1. rationale: enhance cortical reorganization (post stroke)
2. PI= motor (enough to start contraction)
   Waveform: VMS, Russian, symmetric biphasic
3. PR= tetanizing = 50pps
4. PW= wide
5. mod: interrupted 1:3 with ramp
6. electrode placement= motor point or nerve trunk
7. rx time= based on # contractions

Question 24

e-stim for external muscle pump

Answer 24

1. rationale: create mechanical forces to move edema
2. PI= motor
   Waveform: Russian- reciprocal electrodes
3. PR= tetanizing (50pps) or twitch (below 35pps)
4. PW= wide
5. mod: interrupt 1:3 (tet) or 1:1(twitch)
6. electrode placement= motor point
7. rx time = 5-10m

Question 25

e-stim for edema (electro-osmosis)

Answer 25

1. rationale= edema is (-) so place (-) electrode on edema to repel it 2. PI= sub-motor 3. PR= **high** 120- need to get polarity monophasic pulsatile* 4. PW= wide 5. mod= continous 6. electrode placement = (-) over edema, (+) 4in proximal 7. rx time = 20m -1h

Question 26

testing nerve damage severity | r/d(4)

Answer 26

1. reaction of degeneration (R/D) test is based on that nerve is more excitable than muscle so you can activate it in micro-mili seconds and not a muscle 2. short duration current (ac or PC, usually use PC) with unipolar technique- if partial or full response, PNS is intact 3. no response => DC 4. DC if response = full RD (muscle intact, nerve gone) 4. DC if no response = absolute R/D = have more fibrotic tissue than muscle

Question 27

e-stim for wound healing

Answer 27

1. rationale= to mobilize cells to go from phase 1 (inflammatory response) -> phase 2 (proliferation phase) 2. PI= sub motor 3. PR = *high to increase polarity 4. PW= wide 5. mod= continous 6. electrode placement = (+) over wound,(-) large dispersive pad 7. rx time= 1-2hrs- 2x /day