The goal of this clinical trial was to determine whether high-intensity laser therapy (HILT) combined with exercise improves pain, physical function, and muscle strength in people with knee osteoarthritis.

The main questions the study aimed to answer were:

• Did HILT combined with exercise lower pain more than sham laser combined with exercise?
• Did HILT combined with exercise improve physical function more than sham laser combined with exercise?
• Did HILT combined with exercise improve knee extensor muscle strength more than sham laser combined with exercise?

Researchers compared HILT plus exercise with sham laser plus exercise to determine whether HILT provided additional benefits beyond those achieved with exercise alone.

Participants:

• Received either HILT or sham laser treatment for four weeks.
• Participated in a standardized exercise program.
• Completed assessments of pain, physical function, and muscle strength before and after treatment.

Knee osteoarthritis is a common musculoskeletal condition associated with pain, reduced physical function, and muscle weakness. Exercise therapy is widely recommended as a first-line treatment; however, the additional benefits of high-intensity laser therapy (HILT) remain uncertain. Previous studies have reported improvements in pain and function following HILT, but results have been inconsistent, and its effects on muscle strength have not been fully established.

The purpose of this randomized, participant-blinded, sham-controlled clinical trial was to evaluate the effects of HILT combined with exercise on pain, physical function, and knee extensor muscle strength in people with knee osteoarthritis.

Participants with clinically diagnosed knee osteoarthritis were randomly assigned to one of two groups. The experimental group received HILT combined with a standardized exercise program, while the control group received sham laser treatment combined with the same exercise program. The intervention lasted four weeks and included ten treatment sessions.

Pain intensity, physical function, and knee extensor muscle strength were assessed before and after the intervention using validated clinical outcome measures. The primary objective was to determine whether HILT provides additional benefits beyond those achieved with exercise alone.

The findings of this study may help clarify the role of HILT as an adjunct treatment in rehabilitation programs for people with knee osteoarthritis and contribute to the development of evidence-based clinical recommendations.

Inclusion Criteria:

• Clinical diagnosis of knee osteoarthritis.
• Age between 45 and 77 years.
• Pain intensity of at least 3 points on the Visual Analogue Scale (VAS).

Exclusion Criteria:

• Presence of other musculoskeletal conditions affecting the lower limbs.
• History of lower limb surgery.
• Tattoos in the laser application area.
• Recent intra-articular corticosteroid injection.
• Comorbidities limiting participation in physical exercise, such as chronic obstructive pulmonary disease, stroke, or severe heart failure.

De-identified individual participant data underlying the results reported in publications arising from this study will be available upon reasonable request. Data that support the primary and secondary outcome analyses, including pain, functional status, and muscle strength measurements, may be shared after publication of the primary study results. Requests will be evaluated by the Principal Investigator and must include a scientifically sound research proposal. All shared data will be fully de-identified to protect participant confidentiality.

Individual participant data and supporting documents will be available beginning 6 months after publication of the primary study results and will remain available for 5 years thereafter.

Researchers who provide a methodologically sound research proposal may request access to de-identified individual participant data and supporting documents. Requests should be directed to the Principal Investigator. Data will be shared only after review and approval of the proposed use and may require a data sharing agreement to protect participant confidentiality and ensure appropriate use of the data.