High-intensity Laser Therapy and Stretching Exercises for Chronic Non-specific Neck Pain: a Feasibility Study

High-intensity laser therapy (HILT), also referred to as Class IV laser therapy, involves the administration of collimated and monochromatic electromagnetic radiation within the infrared or red spectrum. It operates at power levels exceeding 500 milliwatts (0.5 W), leveraging both photobiomodulation and thermal effects. This distinguishes HILT from Class III lasers (low-level laser therapy, or LLLT), which lack photothermal effects when operating below 500 mW.