Effects of High-Intensity Laser Therapy Combined With Exercise in Patients With Knee Osteoarthritis

Effects of High-intensity Laser Therapy on Muscle Strength in People With Knee Osteoarthritis

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.