Electrode effectiveness during transcutaneous motor stimulation.
Four types of electrodes were evaluated for clinical effectiveness in electrically stimulating the quadriceps muscles to gain knee extension for time periods lasting up to 4 days. These electrodes included self-adhering pregelled pads, solvent-activated conductive tape, carbonized conductive silicone rubber, and felt-covered metal plates. The electrodes were compared for ability to produce knee extension torque, electrical impedance, ease of application, durability, comfort, and skin reactivity. Felt-pad electrodes soaked in tap water or saline produced the highest mean torque and lowest electrical impedance, which made them excellent choices for single session stimulation. Carbon-rubber electrodes with either gel produced slightly less torque, slightly higher impedances, and only minor skin reactions. They were relatively easy to apply, and the majority remained intact for the duration of the study period. They were found to be most suitable for prolonged functional electrical stimulation of the quadriceps. Stimulation using pregelled electrodes produced the lowest torque, and they displayed consistently higher electrical impedance. Even though they were easiest to apply and survived better than the other electrodes, they also produced the most skin reactions. The torque and electrical impedance of the activated-tape electrodes were extremely variable and unpredictable, and the process of application was long and involved, making them clinically impractical for either long or short stimulation.
D000328:Adult; D004553:Electric Conductivity; D004558:Electric Stimulation / Q000009:adverse effects / Q000295:instrumentation*; D004566:Electrodes / Q000592:standards*; D004890:Erythema / Q000209:etiology; D005260:Female; D006801:Humans; D009119:Muscle Contraction; D009132:Muscles / Q000502:physiology*; D013848:Thigh; D013997:Time Factors