ORIGINAL ARTICLE The effect of low-level laser therapy on knee osteoarthritis: prospective, descriptive study Hassan Soleimanpour & Khosro Gahramani & Reza Taheri & Samad E. J. Golzari & Saeid Safari & Robab Mehdizadeh Esfanjani & Afshin Iranpour Received: 15 January 2013 /Accepted: 31 March 2014 # Springer-Verlag London 2014 Abstract Background Osteoarthritis (OA) is one of the most common joint disorders in the elderly which could be associated with considerable physical disability. Patients and methods In a descriptive, prospective study, 33 patients enrolled in the study from which 15 people were excluded due to incomplete course of treatment, leaving the total number of 18 patients with knee osteoarthritis. Gal-Al-As diode laser device was used as a source of low-power laser. Patients were performed laser therapy with a probe of LO7 with a wavelength of 810 nm and 50 mW output power in pulse radiation mode (F =3,000, peak power=80 W, Δt = Authors’ information HS is Associate professor of Anesthesiology and Critical Care, Fellowship in Trauma Critical Care and CPR at the Department of Emergency Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. He is also editorial board member of Emergency medicine journal (EGM) and Pakistan Journal of Biological Sciences (PJBS) and member of World Stroke Organization (WSO), too. KG and RT are anesthesiologists and members of Iranian Medical Laser Asso- ciation, Tehran, Iran. SEJG is an anesthesiologist at the Department of Anesthesiology, Tabriz University of Medical Sciences, Tabriz, Iran. SS is resident of Anesthesiology and Critical Care Department, Iran Uni- versity of Medical Sciences, Tehran, Iran and Managing Editor at Anesthesiology and Pain Medicine Journal. RME is member of Neuro- sciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. AI is anesthesiologist at Saudi German Hospital, Dubai, United Arab Emirates. Electronic supplementary material The online version of this article (doi:10.1007/s10103-014-1576-6) contains supplementary material, which is available to authorized users. H. Soleimanpour (*) Cardiovascular Research Center, Tabriz University of Medical Sciences, Daneshgah Street, Tabriz 51664, Iran e-mail: soleimanpourh@tbzmed.ac.ir K. Gahramani : R. Taheri Iranian Medical Laser Association, Tehran, Iran K. Gahramani e-mail: gahramani_arena@yahoo.com R. Taheri e-mail: dr.reza.taheri@gmail.com S. E. J. Golzari Liver and Gastrointestinal Disease Research Center, Tabriz University of Medical Sciences, Tabriz 51664, Iran e-mail: dr.golzari@hotmail.com S. Safari Anesthesiology and Critical Care Department, Iran University of Medical Sciences, Tehran, Iran e-mail: drsafari.s@gmail.com R. M. Esfanjani Neurosciences Research Center, Tabriz University of Medical Sciences, Daneshgah Street, Tabriz 51664, Iran e-mail: mehdizadeh18@yahoo.com A. Iranpour Saudi German Hospital, Dubai, United Arab Emirates e-mail: af6872@yahoo.com Lasers Med Sci DOI 10.1007/s10103-014-1576-6