Which practice helps maximize electrode conductivity on the skin?

• A. Using plain water only
• B. Applying conductive gel or hydrogel
• C. Using oil-based lotion
• D. Rubbing with dry soap

Answer: (B)

Maximizing electrode conductivity depends on creating a low-impedance, stable interface between the skin and the electrode. Conductive gel or hydrogel provides an ionic bridge that displaces air pockets and lowers resistance, allowing current to flow more evenly from the device into the body. This improves comfort and safety by reducing hot spots and skin irritation.

Plain water can help briefly but tends to evaporate or shift, giving inconsistent conductivity. An oil-based lotion leaves a film that can act as an insulator, increasing impedance. Rubbing with dry soap doesn’t establish a reliable conductive path and can irritate the skin or leave residues that hinder contact.