Related Experiment Video
Updated: May 26, 2026
Method for the Assessment of Effects of a Range of Wavelengths and Intensities of Red/near-infrared Light Therapy on Oxidative Stress In Vitro
Published on: March 21, 2015
Efficacy of low level laser therapy associated with exercises in knee osteoarthritis: a randomized double-blind study
Patrícia Pereira Alfredo1, Jan Magnus Bjordal, Sílvia Helena Dreyer
1Department of Speech Therapy, Physical Therapy and Occupational Therapy, School of Medicine, São Paulo University, São Paulo, Brazil. patriciaalfredo@usp.br
Objectives:
To estimate the effects of low level laser therapy in combination with a programme of exercises on pain, functionality, range of motion, muscular strength and quality of life in patients with osteoarthritis of the knee.
Design:
A randomized double-blind placebo-controlled trial with sequential allocation of patients to different treatment groups.
Setting:
Special Rehabilitation Services.
Subjects:
Forty participants with knee osteoarthritis, 2-4 osteoarthritis degree, aged between 50 and 75 years and both genders.
Intervention:
Participants were randomized into one of two groups: the laser group (low level laser therapy dose of 3 J and exercises) or placebo group (placebo laser and exercises).
Main Measures:
Pain was assessed using a visual analogue scale (VAS), functionality using the Lequesne questionnaire, range of motion with a universal goniometer, muscular strength using a dynamometer, and activity using the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) questionnaire at three time points: (T1) baseline, (T2) after the end of laser therapy (three weeks) and (T3) the end of the exercises (11 weeks).
Results:
When comparing groups, significant differences in the activity were also found (P = 0.03). No other significant differences (P > 0.05) were observed in other variables. In intragroup analysis, participants in the laser group had significant improvement, relative to baseline, on pain (P = 0.001), range of motion (P = 0.01), functionality (P = 0.001) and activity (P < 0.001). No significant improvement was seen in the placebo group.
Conclusion:
Our findings suggest that low level laser therapy when associated with exercises is effective in yielding pain relief, function and activity on patients with osteoarthritis of the knees.
