*Article* **Postural Stability in Single-Leg Quiet Stance in Highly Trained Athletes: Sex and Sport Differences**

**Nebojša Trajkovi´c 1, Darjan Smajla 2,3, Žiga Kozinc 2,4 and Nejc Šarabon 2,3,4,5,\***


**Abstract:** This study aimed to determine if there is a difference in postural stability in highly trained adolescents and young adult athletes regarding sex and sport. The participants were young athletes (*n* = 464) from seven different sports. We considered the center of pressure (CoP) velocity (total, anterior–posterior (AP) and medial–lateral (ML)), CoP amplitude (AP and ML), and CoP frequency (AP and ML), as assessed by single-leg quiet stance test. Significant interactions were found between sex and sport for all CoP variables (*p* < 0.02). Additionally, a significant main effect of sport was also found in all CoP variables (*p* = 0.01). Regarding sex, significant effects were found for all CoP amplitude variables (*p* = 0.01), as well as for CoP velocity variables, except for CoP ML (*p* = 0.06). Moreover, there was no sex effect for CoP frequency AP (*p* = 0.18). The results of the current study confirm the claim that the criteria for optimal postural strategies for elite athletes likely depend on a given sport.

**Keywords:** postural sway; balance; equilibrium; elite athletes; gender effect
