## 4 Discussion  
The main aim of this study was to evaluate the effects of a 10-week sensorimotor exercise programme on the body balance and agility of adolescent football players. The results showed that additional sensorimotor exercises improved body balance and agility. Therefore, it seems reasonable to implement such exercises as a part of training. Analyses of other studies evaluating the effects of additional sensorimotor exercises (described as neuromuscular) on the Y-BT showed similar conclusions [33, 34]. Some similarities regarding the intervention are seen between the present experiment and other works, which likely contribute to their similar results: the intervention was implemented twice per week before the regular training session and included exercises on one foot using an unstable surface. In studies by [PERSON] et al. [33] and [PERSON] et al. [34], female basketball (mean age 20.1 years) [33] and football (mean age 15.1 years) [34] players were selected for the experiment, and additional neuromuscular exercises were introduced for eight weeks. Nevertheless, these authors obtained similar results to the present study, for which the intervention lasted two weeks longer. Opposite results to those in the present study were obtained by [PERSON] and [PERSON] [35], where no improvement in SEBT test scores (an earlier version of the Y-BT) was observed after the introduction of a six-week stabilisation exercise programme in a group of adult runners. This may be due to one of several reasons. [PERSON] and [PERSON] [35] studied runners, whereas in the present experiment the examined group was football players. Each sport discipline is characterised by typical movement patterns [36, 37]. Thus, it can be assumed that the effect of specific exercises on athletes' performance will vary based on the represented discipline. With regard to the stabilometric parameters, the additional sensorimotor exercises introduced in the present experiment for a period of 10 weeks improved the COP (Center of Pressure) value in the 30 s open-eye test. Such results are consistent with other reports [38, 39]. [PERSON] et al. [38] and [PERSON] et al. [39] found improved COP values after 12-week programmes of additional stabilisation [38] and balance [39] exercises prior to regular training in a group of adolescent football players. In the current experiment, no significant improvement in the COP parameter with the closed-eye trial was achieved. Opposite results were obtained by [PERSON] et al. [40] in a study on adolescent volleyball players (mean age 13.2). Unfortunately, we did not find any studies assessing the effects of sensorimotor exercises on the COP value in a 30 s closed-eye test in adolescent footballers. Interestingly, in the present study, the sensorimotor exercises only improved the COP value for the footballers in the 30 s open-eye test. The exclusion of visual control (closed-eye test) as one of the main senses contributes to changes in the central nervous system's precision and postural control (after visual exclusion) [41]. Thus, the area of sway with a participant's eyes opened is unlikely to reflect the postural control mechanisms that were improved after sensomotor exercises [42]. Improvements in neuromuscular and sensomotor function associated with sensomotor exercises help to reduce postural sway to a smaller area and with a lower speed of movement and, subsequently, reduce the need for large postural corrections. The sensomotor exercises introduced were performed without closed-eye tests, which may have indirectly contributed to the lack of improvement in the COP parameters achieved with closed eyes. It may be that the sensomotor exercises excluding visual control would trigger greater compensatory components of the other organs affecting body balance among the young football players and enable improvements in the COP parameters during the closed-eye tests. In the present study, the athletes who underwent 10 weeks of sensomotor training showed significant improvements in track time on the agility test.