Interferential current and photobiomodulation in knee osteoarthritis: A randomized, placebo-controlled, double-blind clinical trial

Objectives: To evaluate the effects of interferential current and photobiomodulation in patients with knee osteoarthritis. Design: A randomized, placebo-controlled, double-blind clinical trial. Setting: Physiotherapy Clinic of City University of São Paulo. Subjects: A total of 184 patients with knee osteoarthritis were recruited and, of these, 168 were included and randomized into four groups with 42 each: interferential current, photobiomodulation, interferential current plus photobiomodulation or placebo groups. One hundred and sixty-four patients completed the study. Intervention: Patients received 12 sessions (three times a week) of treatment: 30 minutes of interferential current (active or placebo) followed by photobiomodulation (active or placebo). Main measures: Primary outcome: pain intensity at rest and during movement (numeric rating scale) after 12 sessions. Secondary outcomes: functional capacity (Timed Up & Go and Sit and Lift tests and Lequesne and WOMAC questionnaires), pressure pain threshold, conditioned pain modulation, and muscle strength production (isokinetic evaluation). Patients were assessed at baseline, after 12 sessions, and three and six months after the end of the treatment. Results: Interferential current plus photobiomodulation reduced pain intensity at rest and during movement compared to placebo and interferential current at all time points (P