"Centering": a fundamental instrument for teaching balance in competitive adolescents

For many years, there has been a debate regarding the role of intra-abdominal pressure (IAP) in supporting thevertebral column, particularly in the lumbar region. The role of IAP is particularly evident during physicalactivities that require complex movements and rapid jumps (Paoli et al., 2010). The hypothesis that IAP relievesthe compressive load on the lumbar vertebrae by better distributing the force vectors during physical activitieswas first proposed in 1923 by Keith and subsequently discussed by Bartelink (Bartelink, 1957). This hypothesiswas later confirmed by Morris et al. in 1961 using a mechanical model. The authors demonstrated that avoluntary increase in IAP alleviates lumbar compression, both directly and indirectly, by inducing spinalextension, causing flattening in the cup-shaped form of the thoracic diaphragm muscle (Morris et al., 1961).Other authors have confirmed the important role of IAP in coordinating the activity of trunk muscles (Stokes etal., 2010; Madle et al., 2022), and its indirect contribution to respiration has been expanded upon and studied(Hodges, 2000). These aspects are crucial for achieving good performance in sports involving acceleration andjumping (Gennaro et al., 2019; Bitnar et al., 2015; Hwang et al., 2021). Therefore, it is possible to activate thecomponents of the trunk stabilization system using its muscles by increasing IAP, which is associated withvoluntary use of the thoracic diaphragm muscles (Stokes et al., 2011). Performance improvement has also beendemonstrated using "Centering" (Debernardi, 2008). "Centering" (CENT) is the proportional utilization of IAPdepending on forces experienced due to the acceleration during sports movements. CENT improves theexecution of technical gestures and their learning (Fogliata et al., 2022). Owing to the importance of CENT inthe stabilization and protection system, the aim of this study was to verify the possible effects of CENT onbalance and stabilization dynamics (Malwanage et al., 2022) and to study possible differences in balancebetween adolescents with and without CENT. Furthermore, the Stork test was employed to identify possiblechanges in balance parameters in adolescents with and without CENT (Condon, 2014).Kay Words: Balancing, Centering, Adolescents Sport.