Efficacy of the Articular Application of Low-energy Laser on Knee Joints as an Auxiliary Treatment for Polyarticular Juvenile Idiopathic Arthritis: A Dual-arm Randomized Clinical Trial

Sixty patients with JIA were recruited from the Physical Therapy Outpatient Clinic of College of Applied Medical Sciences, Prince Sattam bin Abdulaziz University, and the Pediatric Rheumatology Clinic, King Khalid Hospital, Al-Kharj, Saudi Arabia. The study included patients who had a confirmed diagnosis of Polyarticular JIA (according to the criteria set forth by the International League of Associations for Rheumatology), aged 8-16 years, identified being stable cases, and did not participate in a regular exercise program (in the past six months). Patients who had fixed deformities, a history of joint surgery, or whose radiological investigations revealed erosive changes of bone, ankylosing, or fractures were excluded.

Outcome measures

1. Pain intensity: measures through the Visual Analogue Scale
2. Muscle performance: represented by the peak concentric torque of the right and left quadriceps muscle and measured through an Isokinetic Dynamometer.
3. Fatigue perception: tested by the Pediatric Quality of Life Inventory Multidimensional Fatigue Scale (PedsQL-MFS)
4. Functional status: the functional status was quantified using the cross-cultural validated version of the Childhood Health Assessment Questionnaire (CHAQ).

Patients in the control and LLT group received a 40-minute exercise program, three times a week, for three months in succession. Patients in the LLT group additionally underwent an articular application of LLT on the knee joint, each session before exercises (eight points on each knee, 30 seconds irradiation for each point, with a total irradiation dose of eight minutes per session. The treatment was conducted by two experienced pediatric physical therapists.