Rehabilitation technique of proprioceptive neuromuscular facilitation applied to volleyball vertical jump: A randomized double blinded cross-over clinical trial.

Objective: compare the acute effect of lower limb stretching exercises with proprioceptive neuromuscular facilitation (PNF) on the antagonist and agonist muscle groups in the execution of a vertical jump (VJ).

Method: a randomized, double-blind, crossover clinical trial was conducted involving 30 male volleyball athletes. Group A engaged in PNF on the antagonist muscles, while Group B applied the same method to the agonist muscles. Following a 48-h washout period, the interventions were swapped between the respective groups. Both groups underwent assessments averaging three countermovement vertical jumps (CVJ) with hands on hips and three VJ with arms free. Measurement was taken using the Encoder - Ergonauta I, with over 1500 jumps recorded. The participants were evaluated for their level of flexibility and VJ performance using the Jump Sigma Index application.

Results: an acute decrease in average performance was identified, amounting to 3.86 % for the CMJ with hands on hips and 3.06% for the CVJ with free hands, following PNF in the agonists.

Conclusion: there was no statistical difference between the means before and after the intervention when PNF was applied to the antagonistic hamstring muscles. The CVJ modalities with hands on hips and with free hands presented statistically similar indices. The study suggests that there is no impediment to the implementation of warm-up or training protocols that involve stretching in the antagonistic muscles. Further research will be relevant to better clarify the relationship between the effects of stretching on antagonistic muscle groups and to formalize future protocols.