ASSESSMENT OF LIGHT REFLECTION ON HUMAN SKIN IN WHOLE-BODY PHOTOBIOMODULATION THERAPY: RANDOMIZED CLINICAL TRIAL

• Grant number: 23/07857-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2023
• End date: August 31, 2024
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Cleber Ferraresi
• Grantee: Raquel Vendrame Mendes
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Introduction: Photobiomodulation therapy (PBMT) is based on the exposure of biological tissues to low-level laser light or light-emitting diodes (LEDs) that promote modulation of cellular functions and therapeutic effects. The effects of PBMT depend on the light-tissue interaction, which is directly linked to the amount of light that is absorbed by that tissue. When irradiated without contact with the skin, a portion of the incident light suffers reflection, therefore being lost in the application. In this sense, the literature is scarce on studies that evaluated the amount of light reflected in PBMT applied without contact with the skin, in addition to other factors such as skin color (phototype), percentage of subcutaneous fat and gender, which may possibly impact the light reflection. Objective: To quantify the reflection of light from PBMT on the skin of men and women aged 18 to 30 years, considering the influence of skin phototype, percentage of subcutaneous fat and gender. Methodology: This is a randomized clinical trial. 72 volunteers will participate in the study, allocated into 6 equal groups based on skin phototype and sex. The volunteers will be submitted to full-body PBMT (660 nm and 850 nm), and the measurement of light reflection will be performed in the regions of the biceps brachii, abdomen, lumbar, anterior and posterior thigh and calf. A reflection of less than 50% of the incident optical power is expected. The data will be analyzed for their normality of distribution and a significance level of 5% will be adopted.