## 4 Discussion
The addition of WBV during the execution of a specific gesture such as sliding could increase the stimulus at the coordinative level. Recent literature on skill acquisition advocates the use of constraint-based approaches to improve specificity and develop challenging training environments that increase MV and adaptability [21]. Given that responding to different perturbations initiated through various unstable conditions increases the richness of task-specific perceptual-motor experience and therefore improves performance [46; 47], it is considered that understanding MV during the training process may be a key factor for optimising it. The results obtained for peak AceIT and SampEn show differences between leg dominance in all conditions analysed. These results are in line with those found by [PERSON] et al. [48], who reported higher SampEn in the dominant leg during single-leg balance on different surfaces. These results substantiate the hypothesis that the SampEn, a non-linear measure of complexity that measures the variability of a given time series, could reflect an inherent difference in neuromuscular control between the legs. The assessment of postural accelerations has the potential to identify a divergence in postural control between limbs [49; 50], highlighting the bilateral asymmetry in the motor control circuits of the two hemispheres [51]. With regard to AceIT, several studies have shown that the non-dominant leg absorbs impacts worse and shows greater reactive forces in receptions or landings. Therefore, it is likely that in our case, despite the similar speed of both legs, given that the time was set by the metronome, the impact absorption was worse in the non-dominant leg [52; 53]. When constraints are applied to resistance training, it seems that there are changes in the coordination patterns of the system [20; 54]. In the present study, it was observed that the addition of mechanical vibration increased MV. As mentioned above, this is in line with previous authors [31]. However, the addition of the implement (stick) did not produce significant changes, which is contrary to what was found by [PERSON] et al. [20] and [PERSON] et al. [33]. Mechanical vibration has been demonstrated to disturb postural regulation by engaging mechanisms that involve supraspinal structures, resulting in increased phasic muscle activation [55]. Consequently, the increase in MV induced by mechanical vibration can be explained by the acute neuronal modulation triggered by the vibratory stimulus within the central nervous system. It is known that a change in the motor command enhances excitability at the supraspinal level, in a similar way to inhibition at the spinal level. Therefore, there is an increase in cortical activity to control the body's position [56]. Such behaviour implies a modification in the configuration of postural responses concerning external perturbations [57]. Regarding the influence of the stick, no significant differences were reported in the present study when this implement was incorporated, unlike vibration. Previous research suggests that MV can be reduced by a number of factors, including experience and technical gesture control [58; 59; 60]. Considering that they were professional players, the addition of the stick during gliding did not represent an additional stimulus, unlike WBV. Players may be accustomed to using this implement, as it is a common item in their training. One of the main limitations of the present study was the small sample size (n = 10). However, due to the type of sport and the number of federation licenses, we consider the sample to be representative. In addition, all the players belonged to the same club, and there was no representation of players from different categories and sexes.