Abstract
Introduction
Static and dynamic balance are central abilities for everyday activities (Hrysomallis, 2011). When testing dynamic balance, one common measurement is the Y-Balance-Test (YBT). The YBT assesses postural stability by having the participant stand on one leg while reaching with the contralateral leg in three directions: anterior, posteromedial, and posterolateral (Gasavi Nezhad & Arazpour, 2026). Although the YBT is primarily considered a measure of balance, anterior reach performance correlates with dorsiflexion range of motion (ROM), enabling the knee to move beyond the toes allowing a more upright trunk position (Kang et al., 2015; Nelson et al., 2021). Consequently, YBT performance may not only reflect dynamic balance or postural control but also biomechanical factors, potentially limiting the interpretation of YBT outcomes as isolated measures of balance capacity. Although correlational evidence exists, causality between ROM and YBT performance requires further investigation. A practical approach was provided in squat research by using foot wedges under the heel, which led to improvements in stability and ROM (Duan et al., 2025). However, no study has investigated the influence of heel wedge-induced knee-forward movement on YBT performance. This study examines (1) anterior YBT performance under four different wedge conditions (0°, 8.5°, 17°, 25.5°) and (2) the influence of dorsiflexion ROM on YBT performance. Due to known sex-specific differences in dorsiflexion ROM, analyses were stratified by sex.
Method
A randomized crossover design was used. Forty-six participants (female=21, male=25) completed one habituation session, followed by testing YBT, Knee-to-Wall (KTW) for active dorsiflexion ROM, and the passive dorsiflexion ROM assessment using an isokinetic dynamometer. The four wedge conditions were randomized for each participant. Two trials per leg and test were performed, while the best performance was used for statistical analysis. A linear mixed model was used to examine the effects of the four different wedge conditions and the influence of the dorsiflexion ROM.
Results
The results show a significant effect of foot wedge conditions in all three YBT directions (p<0.001, ηₚ²=0.022–0.118). In the anterior direction, the best performance was achieved with an 8.5° wedge in both males and females. The measured active dorsiflexion ROM had no significant effect on anterior YBT performance (p=0.080–0.945). Contrary, for passive ROM, significant sex-specific differences could be observed. Male participants showed significant positive associations between passive ROM and anterior YBT performance across all wedge heights, whereas female participants demonstrated significant negative associations (p<0.001–0.033, ηₚ²=0.010–0.040).
Discussion
As hypothesized, anterior reach performance increased with heel elevation, peaking at 8.5°, before declining at the maximal wedge height (25.5°). These findings are consistent with previous research, which indicates that a moderate heel elevation improves ankle dorsiflexion while maintaining stability, whereas an excessive heel elevation can compromise stability (Duan et al., 2025; Xie et al., 2020). Dorsiflexion ROM did not show consistent associations with YBT performance. The observed sex-specific differences may be explained by different movement strategies between men and women, as factors such as hip mobility, trunk posture, and lower-body strength, in addition to dorsiflexion ROM, can influence YBT performance (Nelson et al. 2021).
References
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