Chapter 12 Review Questions

What seemingly simple fact must be true for the passing of current through an electrode into the skin via an electrode?

The electrodes must be connected to the patient and a stimulator and have an electrically conductive surface

Why are there electrodes of different sizes, shapes, and configurations?

There are different sizes, shapes, and configurations to fit the needs of the therapeutic application of the electrical stimulation for the patient

Why is distilled water an inappropriate choice to hydrate electrodes?

There are no free ions in distilled water to transmit charge

After continued use, all BUT the following statements are true regarding what happens to the conductivity of carbon-impregnated electrodes.

The conductivity is less uniform

Self-adhering single-use or reusable electrodes are composed of flexible conductors that are covered with an electrically conductive interface. When would the use of this type of electrode NOT be advantageous?

If a patient was allergic to the conductive interface

What is a potential disadvantage of self-adhering electrodes?

The resistance exhibited by self-adhering electrodes may be too high

Current density describes the amount of current concentrated under an electrode and is a measure of the quantity of charged particles moving through a specific cross-sectional area of body tissue. What is the relationship between electrode surface area and total current flow?

When the electrodes are small, the current density is high

What happens to current density when two electrodes from one channel of an electrical stimulation unit are different sizes?

There will be a greater concentration of current under the smaller electrode

What is the remedy for restoring a more uniform tingling sensation and decreasing the perception of a “hot spot” under an electrode after electrical stimulation has been applied?

Have the patient make better contact with the electrode that is causing a prickling sensation

What must be true before a clinical electrical circuit is to be considered completed with a patient?

There must be two electrodes connected to a patient. There must be a source of current. There must be two electrodes from one lead

What is the difference between percutaneous and transcutaneous electrodes?

Percutaneous electrodes are inserted into the skin, and transcutaneous electrodes are applied to the surface of the skin

Which technique for the application of electrodes involves a single electrode from a channel, usually smaller in size, placed over the target area called the active electrode?

Monopolar technique

Which technique for the application of electrodes involves the use of two electrodes from one channel within the target treatment area?

Bipolar technique

Which technique for the application of electrodes involves electrodes from two or more channels, each lead with two electrodes, with all four of the electrodes placed in the target treatment area?

Quadripolar technique

Both surfaces of the carbon-impregnated electrodes appear shiny. What might this indicate?

That the electrodes need to be replaced

A PTA is planning to use surface EMG biofeedback to help a patient with complete quadriceps paralysis after a recent spinal cord injury. The goal is to facilitate improved motor activation. Which of the following best explains why this intervention may not be appropriate at this time?

The patient has no voluntary motor control of the quadriceps

A patient is recovering from a total knee arthroplasty (TKA) and is having difficulty activating the quadriceps muscle due to pain and post-surgical inhibition. The physical therapist includes EMG biofeedback as part of the intervention plan. Which of the following best describes how biofeedback contributes to the patient's rehabilitation goals?

It promotes long-term neuromuscular control by retraining voluntary muscle activation