INTRODUCTION:
Proprioception is an essential variable for prevention and rehabilitation of knee injuries and can be stimulated by different equipment, which have not yet been tested in water.
OBJECTIVE:
To evaluate the electromyographic (EMG) activity of the rectus femoris muscle of athletes in aquatic environment using three different proprioceptive equipment (trampoline, balance disc and rocker board).
METHODS:
The sample comprised ten professional futsal players with no history of musculoskeletal injuries (last three months), with 23.1 (±1.5) years old and body mass index of 25.2 (±0.5) kg/m². The EMG of the rectus femoris of the dominant member was acquired by placing surface electrodes approximately 2.5cm from the distal position of the motor point. The water level was individually adjusted (between the umbilical region and the xiphoid process) and the temperature was maintained at 32ºC. The evaluations included rest, maximum voluntary contraction (MVC) before and after the experiments and proprioceptive stimuli (trampoline, balance disc and rocker board) in one leg. The data (mean ± standard error) were compared by paired t-test and ANOVA for repeated measures followed by Bonferroni post-hoc test.
RESULTS:
The EMG of MVC before (221.0 ± 134 RMS/µVolts) and after (243.0 ± 154.0 RMS/µVolts) were similar (p=0.129). In the aquatic environment, the trampoline, the rocker board and the balance disc showed respectively 24.5 (±4.3), 33.9 (±4.3) and 32.5 (±6.7) %CVM. The EMG activity of the rectus femoris muscle in the trampoline was 8% lower than the rocker board and 9.5% than the balance disc (p<0.001).
CONCLUSION:
In the aquatic environment proprioceptive equipment promote the activation of the rectus femoris muscle. However, the trampoline has lower activity than the disc and the rocker board, suggesting that this equipment should be employed at the beginning of the proprioceptive stimulation.
electromyography; hydrotherapy; proprioception
