INTRODUCTION: Studies show that laser therapy can increase muscle performance and delay the process of muscle fatigue. However, few studies have reported photogrammetry as a tool to analyze muscle performance. The objective of this study was to assess the possible effects of phototherapy in relation to activity and muscle fatigue. METHODS: We performed a crossover, randomized, double-blind, controlled trial with seven healthy female volleyball players. The muscle activities were quantified through electromyography, and jumps were quantified through photogrammetry Laser therapy (830 nm, 30 mW, 11 J per point and 22 seconds) was carried out on 3 cm² triceps surae muscle for an average of 20 points. The Kolmogorov-Smirnov test was used to analyze data distribution. RESULTS: After testing for normality, the Student t test was applied, considering a significance level of 5% (p <0.05). The laser had no effect with respect to the variables studied. Interestingly, a significant difference in motor recruitment values of the lateral gastrocnemius muscle was observed during plantarflexion movement. CONCLUSION: Although many studies have shown a correlation of phototherapy with muscle activity and fatigue, this study found no correlation of laser therapy with muscle activity or fatigue.
Laser therapy; Photogrammetry; Muscle performance; Muscle active; Fatigue