What type of current combines two medium frequency currents for therapeutic effects?

Interferential current is a type of electrotherapy that combines two medium-frequency alternating currents. This is achieved by delivering these currents simultaneously, resulting in an interference pattern when they intersect in tissue. This interference creates a range of therapeutic effects that can help alleviate pain, reduce inflammation, and stimulate muscle contraction more effectively than using a single current.

The medium frequency of the currents used in interferential therapy allows for deeper penetration into tissues compared to lower frequency currents, making it particularly beneficial for treating various musculoskeletal disorders and promoting muscle relaxation. The dual-frequency approach facilitates the modulation of the current, which enhances the therapeutic outcomes and can be adjusted for comfort and efficacy tailored to the patient's needs.

In contrast, galvanic current is a continuous direct current used primarily for its ionization and chemical effects. Cathodic current specifically refers to the negative pole in galvanic therapies. Faradic current is another form of stimulation, typically associated with muscle contraction but does not involve the layering of two medium-frequency currents. Thus, the unique mechanism of interferential currents distinguishes it as the correct answer for this question.