Photobiomodulation therapy for chronic knee pain in obese patients in pre-rehabilitation for bariatric surgery: randomised, placebo-controlled, double-blinded, clinical trial protocol.

Introduction: Obesity has become a worldwide public health problem and is directly linked to loss of quality of life, complications and comorbidities. One of them is chronic pain, especially in the knees, which increases significantly and proportionally with weight gain. In patients with severe obesity, with indication for bariatric surgery, the presence of chronic pain disables and often prevents their participation in a pre-surgical rehabilitation programme.