Effects of Carbon Dioxide Infrared Laser Moxibustion on Pain and Function in Knee Osteoarthritis

Summary

Knee osteoarthritis is a prevalent degenerative joint disorder characterized by chronic knee pain, stiffness, reduced range of motion, and limitations in daily functional activities. Exercise therapy is widely recommended as a first-line conservative approach to reduce symptoms and improve physical performance; however, a substantial proportion of patients continue to experience persistent pain and functional impairment despite adherence to exercise-based rehabilitation.

Carbon dioxide (CO2) infrared laser moxibustion is a non-invasive far-infrared thermal stimulation modality intended to reproduce the localized heating effects of traditional moxibustion without smoke or odor. It is hypothesized to enhance local microcirculation, support tissue oxygenation, and modulate inflammatory activity, thereby contributing to symptom relief and improved joint function. This double-blind, parallel-group randomized controlled trial will evaluate whether adding carbon dioxide (CO2) infrared laser moxibustion to a standardized knee osteoarthritis exercise program provides greater improvement than exercise alone. Eligible participants with radiographic knee osteoarthritis will be randomly allocated to either (1) an exercise-only program or (2) the same exercise program plus carbon dioxide (CO2) infrared laser moxibustion delivered over an 8-week treatment phase (24 sessions). Outcomes will be measured at baseline and at follow-up visits at Month 3 and Month 6 to determine changes in pain intensity measured by the Numerical Pain Rating Scale (NPRS), knee range of motion measured by goniometry, articular cartilage thickness measured by magnetic resonance imaging (MRI), and biochemical markers including bone alkaline phosphatase (BAP) and serum calcium.

Conditions

• Knee Osteoarthritis

Interventions

OTHER

Exercise Program for Knee Osteoarthritis

Participants receive a standardized knee osteoarthritis exercise program delivered over an 8-week intervention period, with three supervised sessions per week (24 sessions total), with each session lasting approximately 40 minutes. The program includes warm-up activities followed by progressive strengthening and mobility exercises targeting the knee and surrounding musculature, including step-ups, chair sit-to-stand exercises, quadriceps strengthening, isometric thigh activation, and balance or coordination exercises.

DEVICE

CO2 Infrared Laser Moxibustion (CILM)

CO₂ infrared laser moxibustion is administered using a 10.6 μm CO₂ infrared laser device with an output power range of 160-180 mW. The defocused probe is positioned approximately 2 cm from the skin, producing a light spot with a diameter of approximately 2 cm. Irradiation is applied to predefined knee-related points (ST35, Ex-LE4, and Ashi points) bilaterally, with each point treated for approximately 5 minutes per knee. The total irradiation time per session is approximately 30 minutes, including bilateral point application, with additional time allocated for positioning and safety checks, resulting in a total session duration of approximately 40 minutes. Treatment is delivered three sessions per week for eight weeks (24 sessions total) according to a standardized protocol.

Sponsors & Collaborators

• University of Lahore

  lead OTHER

Principal Investigators

• Ashfaq Ahmed · University Institute of Physical Therapy Univesity of Lahore Pakistan

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

55 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-10-26

Primary Completion

2026-03-30

Completion

2026-07-30

Countries

• Pakistan

Study Locations