Interferential current therapy in patients with knee osteoarthritis: comparison of the effectiveness of different amplitude-modulated frequencies.

Objective: This study aimed to compare the effectiveness of different amplitude-modulated frequencies of interferential current (IFC) and sham IFC on knee osteoarthritis.

Design: A randomized and single-blind study was performed on 60 patients diagnosed with knee osteoarthritis. The patients were allocated to three active IFC groups (40, 100, and 180 Hz), and one sham IFC group.