Electrical Stimulation

Question 1

name some roles of biophysical agents and why how they help

Answer 1

• control pain, edema, and inflammation by decreasing pain?
• facilitate tissue healing
• reeducate lost or impaired function by decreasing spasm and increasing muscle force/function
• control symptoms from ROM exercises, manual therapy, muscle strengthening, motor reeducation

Question 2

what kinds of e-stim work with sensation?

Answer 2

TENS - decreases pain

Question 3

what kinds of e-stim work with motor? (ie muscle strengthening/reeducation/substitution)

Answer 3

NMES - re-education and strengthening

FES - muscle substitution

Question 4

when would you want to use e-stim?

Answer 4

injuries, chronic pain, weakness or loss of function, spasticity or wound healing

Question 5

in a neuron, is the inside more negative or positive

Answer 5

inside is more negative

Question 6

force-frequency relationships are what kind of relationships?

Answer 6

sigmoidal, needs 30-85Hz for max tetanic rxn

Question 7

to create max tensions voluntarily, one needs high frequency or low?

Answer 7

lower

Question 8

what does moving the electrodes farther apart do?

Answer 8

deepens the current

Question 9

what two factors determine whether you are targeting sensory vs motor stimulation?

Answer 9

threshold of activation of nerve types and intensity of stimulating current

Question 10

what is the difference between the order of natural muscle recruitment and e-stim recruitment? why is this different?

Answer 10

natural = small to large fibers
e-stim = large to small fibers
the difference is because larger muscles have lower imput resistance so are more easily recruited by e-stim

Question 11

what is impedance?

Answer 11

resistance of tissue to electrical current

Question 12

where is current density the hightest?

Answer 12

near the surface of tissue

Question 13

what can change current density?

Answer 13

change size of electrode, smaller electrode active and larger electrode dispersion

Question 14

what are the two main factors used to create an action potential using e-stim?

Answer 14

strength and duration of pulse (intensity and pulse duration)

Question 15

what is a rheobase? and a chronaxie?

Answer 15

minimum current needed to produce an action potential at a long pulse duration.

minimum duration that will produce an action potential twice the rheobase

Question 16

what is the range of normal pulse duration?

Answer 16

100-350ms, should be below 1s

Question 17

What type of muscle fiver is the least resistant to fatigue? What is the best type of stimulation frequency for this type?

Answer 17

Type 2b (fast oxidative) - high stimulation frequency

Question 18

What are the 3 parameters of e-stim

Answer 18

Waveform shape and duration, time between pulses

Question 19

When should you not do e-stim

Answer 19

Cardiac pacemakers and arrhythmia
Over carotid sinus
Thrombosis
Pregnancy (on baby)
Trans thoracic or trains cranial