Effects of holographic bracelet on balance and muscle performance in soccer players: A quintuple-blind, placebo-controlled, crossover randomized clinical trial

Abstract

This study aimed to analyze the influence of holographic bracelets on body balance and peak torque in soccer athletes through a quintuple-blind, placebo-controlled, crossover randomized trial. Twenty-eight male athletes were evaluated in a sta- bilometric baropodometer (DIASU ) and performed a protocol involving concentric contractions of the knee at 60 ◦ /s. Athletes were evaluated in three situations: no bracelet (baseline), with a placebo bracelet (PB) and holographic bracelet (HB). Comparing the mean torque peak at 60 ◦ /s during knee extension, there was no statistical difference for the dominant limb (p = 0.713) and non-dominant (p = 0.996) between the baseline, PB and HB groups. No statistical difference was found comparing the mean oscillation ellipses from the right foot with eyes open (p = 0.359) and with eyes closed (p = 0.173), as well as from the left foot with eyes open (p = 0.891) and with eyes closed (p = 0.778). In conclusion, holographic bracelet has no influence on either body balance or knee muscle performance in athletes.