Biathletes Prefer a Closed-Looped Strategy to Maintain Their Balance During Shooting

Background: Balance can also be a main factor contributing to success in many disciplines, and biathlon is a representative example. The center of foot pressure (COP) is commonly recorded when evaluating postural control. Because COP measurements are highly irregular and non-stationary, the non-linear deterministic methods are more appropriate for the analysis of COP displacement, such as entropy. The aim of our study was to investigate whether the longitudinal effects of biathlon training can elicit specific changes in postural control. Methods: : 8 national-level biathletes, 15 non-athletes who prior to the experiment took part in 3 months of shooting training, and 15 non-athletes with no prior rifle shooting experience. The data was collected with the use of a force plate. Participants performed three balance tasks in quiet standing, the shooting position (internal focus), and aiming at the target (external focus). Results: : Biathletes obtained significantly lower values of sample entropy compared to the other groups during shooting and aiming to the target trials (p0.05). External and internal focuses influenced the process of postural control among participants who had prior rifle shooting experience and the control group: they obtained significantly higher values of sample entropy during shooting and aiming to the target compared to the quiet standing trial (p<0.05). The biathletes obtained contrary results. There were no significant differences in the values of sample entropy between three consecutive trials in the ML plane; there was only one significant change in the AP plane. The biathletes obtained significantly lower values of sample entropy in aiming to the target position compared to the quiet standing trial. Conclusion: Specific balance training is associated with the ability to deal with a more challenging nonspecific task. The biathletes seemed to employ a different motor control strategy than the beginners and control group. They create repeating patterns (more regular signal for COP), which is a vigilant closed-loped strategy to keep one’s balance during the shooting and aiming to the target positions.