Abstract
BACKGROUND: Although the World Karate Federation (WKF) lacks a standardized test battery, Para Karate classification follows International Paralympic Committee (IPC) principles, with balance recognized as a key physical ability affecting kata performance. This study aimed to compare postural stability across categories and classes of top-level Para Karate athletes and to provide evidence supporting classification refinement. METHODS: Fifty-nine athletes competing at the 2023 World Para Karate Championship were classified into three groups: visually impaired (VI, n = 24, age 23.8 [20.6] years), intellectual impairment (II1, n = 17, 26.5 [9.7] years), and intellectual impairment with additional impairment (II2, n = 18, 28.0 [11.3] years). A 30-second bipedal stance test with eyes open was used to assess total path and area of the centre of pressure (CoP), including anterior-posterior (AP) and medio-lateral (ML) directions. Non-parametric Kruskal-Wallis H test and Mann-Whitney U test were used for analysis. RESULTS: Significant group differences were observed for total CoP path (H((2)) = 13.205, p < 0.001) and area (H((2)) = 12.929, p = 0.002). II1 athletes demonstrated significantly lower CoP path than VI (p(adj)=0.001), with better AP stability compared to both groups. II2 class had lower total CoP area than VI (p(adj)<0.001). They showed the lowest area in AP direction compared to both VI and II1 (p(adj)=0.002 and p(adj)=0.040, respectively). CONCLUSIONS: The 30-second balance test proved to be sensitive to between-group differences in postural control among impairment types. VI athletes exhibited greater CoP path than II1 athletes and greater CoP area than II2 athletes, highlighting the need for targeted balance training. In the AP direction, II1 athletes showed better control in path length compared to both groups, while II2 athletes outperformed them in sway area. However, the area parameter demonstrated limited reliability, and its results should therefore be interpreted with caution. Based on these findings, detected inter- and intra-group variability may contribute to building a robust evidence base for future classification development of Para Karate athletes.