title: Phototherapy effect on the muscular activity of regular physical activity practitioners.
abstract: Clinical investigations have demonstrated the effectiveness of phototherapy on the muscle activity. The aim of this study was to investigate the effect of low-level laser therapy (LLLT) on the tibialis anterior muscle of regular physical activity practitioners by electromyographic, biomechanical, and biochemical (lactate) analysis. Double-blind controlled clinical trials were conducted with 12 healthy females, regular physical activity practitioners, between 18 and 30 years. The LLLT application (780 nm, 30 mW, 0.81 J/point, beam area of 0.2 cm(2), 27 s, ≈ 29 points) in the tibialis anterior muscle occurred after the delimitation of the points on every 4 cm(2) was held. It was observed that (a) a significant torque increase (p < 0.05) post-LLLT compared to the values after placebo therapy at the beginning of resistance exercise, (b) both muscle torque (isokinetic) and median frequency (EMG) showed a faster decay of the signals collected after placebo and laser treatment when compared to control values, (c) no significant change in torque in the strength test of five repetitions, (d) a significant muscle activity decrease (p < 0.05) after laser therapy compared to control values, and (e) an increase in lactate levels post-LLLT (p < 0.05) after 30 min of exercise. It is concluded that the LLLT increased the muscle torque at the beginning of the exercise and maintained the levels of lactate after resistance exercise. Therefore, the LLLT with the parameters used in this study can be utilized in rehabilitation to improve muscle performance in elite athletes.
authors.affiliation: Phototherapy and Photobiology Center and Biologic Signal Processing Laboratory, UNIVAP, São José dos Campos, São Paulo, Brazil, macielts@hotmail.com.
authors.forename: Thiago
authors.initials: T
authors.lastname: dos Santos Maciel
authors.forename: Ingrid Solange Sepúlveda
authors.initials: IS
authors.lastname: Muñoz
authors.forename: Renata Amadei
authors.initials: RA
authors.lastname: Nicolau
authors.forename: Daniel Vilela
authors.initials: DV
authors.lastname: Nogueira
authors.forename: Leonardo Alvim
authors.initials: LA
authors.lastname: Hauck
authors.forename: Rodrigo Alexis Lazo
authors.initials: RA
authors.lastname: Osório
authors.forename: Alderico Rodrigues
authors.initials: AR
authors.lastname: de Paula Júnior
mesh_terms: D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D009043:Motor Activity; D018482:Muscle, Skeletal / Q000502:physiology* / Q000528:radiation effects*; D010789:Phototherapy / Q000379:methods*; D019415:Torque
chemical_list: D019344:Lactic Acid