Settings for re-ed?

• A. waveform- monophasic
• B. waveform- triphasic
• C. waveform- asymmetrical biphasic
• D. waveform- symmetrical biphasic

Answer: (D)

Re-education with electrical stimulation relies on producing controlled, comfortable muscle contractions without causing tissue irritation or a buildup of charge at the skin. The best choice is a symmetrical biphasic waveform because it delivers equal positive and negative phases within each pulse, resulting in a net zero charge over time. That balance reduces electrode polarization, minimizes skin irritation and chemical changes at the contact site, and generally feels smoother and more comfortable for the patient. This comfort and safety support longer, more effective re-education sessions.

Monophasic currents have a net direct current component, which can cause skin irritation, polarization, and less comfortable contractions—undesirable for re-education. Asymmetrical biphasic waves are not perfectly balanced, so they can still carry a small net charge and may cause similar issues, making them less ideal than the balanced symmetrical biphasic waveform. Triphasic currents introduce another phase arrangement that isn’t the standard for NMES re-education and can produce less predictable recruitment and comfort.