Revisão de literatura da influência da biofotomodulação na força e hipertrofia muscular: quais parâmetros e métodos utilizar?

Abstract

The photobiomodulation (PBM) is widely used in the context of Physical Therapy, both for the treatment of injuries and the treatment of pain, however, PBM can also be used to increase muscle performance. There are some studies proving its effectiveness in increasing muscle strength and hypertrophy. However there still are doubts about the best way to use it. Therefore, the presente study aims to evaluate and describe the main current evidence available on the influence of PBM on muscle strength and hypertrophy, searching the best parameters for the use of this resourse. For this, literature review was carried out on studies that used PBM and evalueted muscle strength and/or muscle strength in young individuals. Searches were carried out in two databases: PubMed and SciELO, using the follow keywords: laser, low level laser therapy, low level light therapy, photobiomodulation, ledt, phototherapy, hypertrophy, muscle hypertrophy, strength, muscle growth, muscle size and strength training. Two filters were applied during the search, publication date up to ten years and randomized controlled trials. Eligible studies needed to use PBM in muscle as intervention and assess muscle strength and/or muscle hypertrophy before and after the intervention. Studies published in languages other than English and Portuguese, papers that used volunteers with any pathology or over 60 years and dental studies were not included. Only nine studys were inclued in this review. Sample characteristics, methodological quality of studies, characteristics of the training protocol, used BPM parameters and the outcomes and results evaluated were analyzed. Four of the nine studies included investigated the influence of PBM on strength loss after exercise, five investigated the influence of PBM on muscle strength gain, and two investigated the influence of PBM on muscle hypertrophy. Seven studies showed positive results in relation to muscle strength and only one in relation to muscle hypertrophy. The best time to apply the resource seems to be before the exercise protocol. There was no consensus regarding the dosage used or the wavelength. Regarding muscle strength, this review showed positive results, although, further studies are still needed for a better understanding of which dosage and wavelength to use. For muscle hypertrophy, there are still few papers available, which indicates the need for futher studies on this subject.