Which therapy modality uses alternating current to stimulate muscles?

The correct response is based on the principle of how interferential current therapy works. Interferential current utilizes two high-frequency alternating currents that intersect at a specific point in the body. This intersection creates a low-frequency current which effectively stimulates the underlying tissues, particularly muscles. The particular advantage of this modality is its ability to penetrate deeper tissues without discomfort, making it effective in pain management and muscle stimulation.

In contrast, transcutaneous electrical nerve stimulation (TENS) primarily utilizes low-voltage electricity for pain relief but does not specifically target muscle stimulation through alternating currents in the same way. Manual therapy involves physical manipulation of muscles and joints without the use of electrical stimulation, while thermal therapy typically involves heat or cold applications to reduce pain and inflammation. None of these modalities utilize the alternating current characteristic that is fundamental to interferential current therapy.