Which feature of IFC contributes to deeper tissue penetration compared with conventional TENS?

• A. Beat frequency from two medium-frequency currents
• B. Higher current amplitude
• C. Longer treatment duration
• D. Use of pulsed mode

Answer: (A)

Interferential current therapy achieves deeper penetration by using two medium-frequency currents that cross in the tissue and interfere with each other. Each carrier is high enough to pass through skin with less impedance, so more energy reaches deeper tissues. Where the two currents intersect, they create a beat frequency equal to the difference between their frequencies. That low-frequency beat stimulates nerves at depth, while the high-frequency carriers maintain a comfortable skin sensation. So the depth comes from the combination of high-frequency carriers to bypass skin impedance and a low-frequency beat produced inside the tissues. Higher amplitude, longer treatment duration, or pulsed mode aren’t the primary reasons for deeper penetration.