Electro Review

Electro Basics

100

What is the term that refers to the net charge (negative or positive)?

Polarity

200

True or false: myelin sheath serves as a conductor.

False. Myelin sheath is an insulator. The nerve axon serves as a conductor.

300

When electrical signal is sent into the body, it moves ions, which creates friction/vibration generating heat. This is known as the ___________ physiologic response.

Electrothermal

400

As you increase amplitude, your patient reports sensation of the stimulation, followed by a motor contraction, and lastly by sensation of pain. Is this a normal sequence of events?

Yes. Due to larger size, more superficial location, and increase myelination, sensory nerves are activated first, followed by motor nerves, and pain sensing nerves last. 

500

What are the 3 factors that influence the excitatory response of the muscle (assuming the mm is fully innervated)?

SD curve, nerve size, and location of electrodes

E-stim Basics

100

How would you describe the gate keeper and endogenous opiates theory to your patient?

interruption of pain signal, change in perception of pain, release of natural chemicals in the body that make pain feel better.

200

True or false: NMES recruits mm fibers in the same pattern as volitional contraction.

False. Alternative pattern of recruitment based on proximity to stimulation.

300

Which of the following type of e-stim is most likely to utilize a monopolar electrode configuration?

A. NMES

B. LIDC

C. IFC

D. Noxious TENS

B

400

What are common parameters settings (ranges) for conventional TENS

Frequency:

Pulse duration:

Amplitude: (goal)

Duration:

Freq: high 50-150 pps

PD: Short 50-100 msec

Amp: mild tingling sensation

Duration of painful activity

500

You've adjusted NMES parameters. With the same electrode placement and parameters, you notice a decreased, delayed, and inconsistent motor response from the mm. What is likely the cause?

Peripheral nerve injury with some remaining innervation.

Patient application

100

Why do we need a duty cycle (on/off times) for NMES?

To allow full repolarization during the off time, therefore permitting another full, strong contraction during the on time.

200

Your patient reports absent light touch sensation to the left half of their body following a stroke. Can you still use FES?

Yes, impaired sensation is a precaution, not a contraindication.

300

What are two common uses for muscle EMG within PT?

Muscle EMG can be used to diagnose (often paired with NCVT) or for biofeedback.

400

What types of current can be utilized for wound/tissue healing?

DC (LIDC) or monophasic pulsed current (HVPC)

500

You receive an Rx to provide 2% calcium chloride (-) at a dose of 80 mA-min to your patient's right upper trap muscle to help with pain and muscle spasms. Which electrode would act as the active electrode? 

At a current of 4.0 mA, how long would it take to deliver the dose?

Cathode and 20 minutes

Safety

100

After e-stim, your patient's redness should go away within ____ hours.

3

200

If your patient is coming to with weakness and pain after surgery, what additional question should you ask the patient (or the surgeon) before provoking a motor response?

Ensure your patient does not have any precautions or restrictions in movement.

300

Rank the following types of current in order of highest risk of adverse event to lowest risk.

1. Monophasic pulsed current

2. Direct current 

3. Alternating or biphasic pulsed current

1. Dc

2. Monophasic PC

3. AC or biphasic PC

400

Which physiologic response explains why iontophoresis has the highest safety risk and requires more frequent skin checks?

The electrochemical response

500

What are two additional contraindications that you must screen for before applying iontophoresis?

1. drug allergies

2. skin sensitivity