Electrical Stimulation

Question 1

Indications for e-stim

Answer 1

• Pain modulation
• Muscle spasms
• Improve ROM
• Muscle re-education
• Strength/prevent atrophy
• Edema reduction
• Wound healing
• Stimulate denervated muscle

Question 2

E-stim precautions

Answer 2

• Cardiac disease
• Impaired mentation
• Impaired sensation
• Skin irritation/open wounds
• Controlled BP issues
• Bleeding disorders

Question 3

e-stim contraindications

Answer 3

• Electronic medical device (PACEMAKER)
• Over carotid artery, thrombosis, eyes, phrenic nerve, pelvis +/- LB in pregnancy
• Active DVT
• Transcerebrally
• Active bleeding or infection
• Superficial metal implants
• pharyngeal or laryngeal muscles
• Motor-level stimulation in conditions that prohibit motion

Question 4

Polarity

Answer 4

net charge of object

Question 5

Voltage

Answer 5

driving force that moves electrons

Question 6

Current

Answer 6

movement of ions or electrons in a conductor

Question 7

Ohm’s Law

Answer 7

expresses the relationship between current, voltage, and resistance.

Question 8

All of the following reduce resistance to ensure adequate current flow with e-stim, EXCEPT:
a. minimize the air-electrode resistance
b. using the smallest electrode that will illicit desired response.
c. ask the patient to shave and not wear lotion prior to PT
d. Keep the electrodes clean

Answer 8

b. using the smallest electrode that will illicit desired response.
- You would want to use the largest electrode to reduce discomfort and reduce risk of burns.

Question 9

Direct current

Answer 9

unidirectional, uninterrupted flow of charged particles.

Question 10

Common uses for direct current include all of the following except (select all that apply):
- pain modulation
- edema control
- wound care
- iontophoresis
- muscle re-education

Answer 10

pain modulation, edema control, muscle re-education (only used for wound care and iontophoresis)

Question 11

Alternating current

Answer 11

uninterrupted bidirectional flow

Question 12

Pulsed current

Answer 12

unidirectional or bidirectional current that periodically ceases for a very short time period.

Question 13

Frequency

Answer 13

of pulses/sec

Question 14

Pulse duration (width)

Answer 14

how long each individual pulse lasts

Question 15

Amplitude

Answer 15

voltage of each individual pulse

Question 16

If your goal is to elicit maximum muscle contraction - would pulse or direct current be more appropriate?

Answer 16

Pulsed as it allows for successive depolarization and repolarization

Question 17

E-stim causes depolarization of _________ before the _______ critical threshold is reached.

Answer 17

nerve, muscle

Question 18

T/F The amplitude (intensity) of a stimulus must be GREAT enough to lower the membrane potential to reach the critical threshold to induce depolarization.

Answer 18

True

Question 19

What physical signs will be present to ensure you have set the e-stim to sufficient amplitude (intensity) for nervous tissue?

Answer 19

pt will report a tingling sensation

Question 20

What physical signs will be present to ensure you have set the e-stim to sufficient amplitude (intensity) for muscle tissue?

Answer 20

active muscle twitch is visible

Question 21

Heat from e-stim is created by _________ and __________ of particles moving through the material.

Answer 21

friction, vibration

Question 22

Current density is affected by the current setting and the size of the electrode.
In general, the _________ the electrode the LESS current density.
The ________ current the LESS current density

Answer 22

larger electrode size, lower current

Question 23

Monopolar electrode placement

Answer 23

one small electrode over target area and a large electrode place over a remote area.

Question 24

If I am trying to attract negatively charge cells to an area - what terminal does the treatment electrode need to be plugged into?

Answer 24

Positive

Question 25

Which waveform can NOT be used with bipolar?

Answer 25

direct

Question 26

Your patient is having sciatica pain and you have determined you want to use e-stim to help with pain modulation. What placement considerations do you need to keep in mind?
a. place over the sciatica dermatomal pathway in a monopolar fashion.
b. place over the muscle belly or proximal 1/3 of the muscle in a monopolar fashion.
c. place over the sciatica dermatomal pathway and in a bipolar fashion
d. place over the muscle belly or proximal 1/3 of the muscle in a bipolar fashion

Answer 26

c. place over the sciatica dermatomal pathway and in a bipolar fashion

Question 27

You asked a PTA to place your patient on e-stim over their soleus so you could get started with your next patient. The patient on e-stim calls you over and says it is really uncomfortable. When you check the electrode application - what would you observe that would INCREASE patient discomfort? (choose all that apply)
a. large electrode size relative to the muscle
b. small electrode size relative to the muscle.
c. Electrode A placed over the G/S complex region and electrode B placed over the bottom of the foot.
d. electrode A placed on the medial border of the G/S complex and electrode B placed on the lateral border

Answer 27

b. small electrode size relative to the muscle.
AND
c. Electrode A placed over the G/S complex region and electrode B placed over the bottom of the foot. (one electrode over a muscle belly and the other over a distal area w/o much muscle)