One hundred patients with knee osteoarthritis were randomized to receive an 8 week exercise program alone or in addition to interferential current therapy, shortwave diathermy, photobiomodulation or placebo. The primary outcome of interest was physical function score on the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis index. Secondary outcomes of interest included WOMAC pain and stiffness scores, pain on a Numeric Rating scale (NRS), pain pressure threshold, self-perceived fatigue on the World Health Organization Quality of Life (WHOQOL) questionnaire, and the sit-to-stand test. Results were assessed upon completion of the 8 week program. Results revealed that the addition of interferential current therapy, shortwave diathermy and photobiomodulation did not significantly improve clinical outcomes compared to exercise alone. The exercise only group displayed significantly greater improvements in WOMAC pain and function, however these differences were not clinically relevant.