Lower-limb dynamic stability profile and its association with functional hop performance in female football players

Introduction: Female football involves frequent accelerations, decelerations, cutting maneuvers, jumping, landing, and single-limb support, all of which place high demands on lower-limb dynamic stability and neuromuscular control (Mara et al., 2017). Dynamic postural control plays an important role in the execution of these movements and is commonly evaluated using functional performance tests. The Y-Balance Test is widely used to assess dynamic postural control through reach performance in the anterior, posteromedial, and posterolateral directions. The Figure-of-8 Hop Test, on the other hand, assesses single-limb functional performance under more dynamic conditions involving hopping, directional changes, speed, and coordination (Docherty et al., 2005; Plisky et al., 2021). Despite the frequent use of both assessments in sports settings, it remains unclear to what extent they evaluate related aspects of lower-limb dynamic stability in female football players. Therefore, the aim of this study was to assess the relationship between performance in the Y-Balance Test and the Figure-of-8 Hop Test in female football players and to examine the interlimb asymmetries between the dominant and non-dominant limbs.Methods: Twenty female football players (18.9 ± 3.2 years; 166.5 ± 7.4 cm; 60.6 ± 7.9 kg; 14.9 ± 5.9 years of playing experience) underwent functional testing on both lower limbs. The testing protocol included the Lower Quarter Y Balance Test (LQ-YBT) and the Figure-of-8 Hop Test. During the LQ-YBT, participants stood barefoot on one limb in the center of a Y-shaped grid and reached as far as possible with the contralateral limb in three directions: anterior, posteromedial, and posterolateral. Following a standardized warm-up and familiarization trial, each participant performed three recorded trials for each limb and direction. Reach distances were normalized to lower limb length, measured from the anterior superior iliac spine to the medial malleolus, and expressed as a percentage of limb length. The Figure-of-8 Hop Test was performed on a 5-m course marked with cones. Participants were instructed to hop on one limb along a figure-of-eight path as quickly as possible. The course was completed twice without interruption. If a participant lost balance or touched the ground with the non-tested limb, the trial was repeated. The test emphasized speed, accuracy, and the ability to maintain dynamic balance during movement. Performance was recorded as the time required to complete the task, expressed in seconds. The test was performed bilaterally. The dominant leg was determined as the preferred leg for kicking. Due to the small sample size and partial violation of normality assumptions, relationships between variables were analyzed using Spearman’s correlation coefficients with a significance level set at α = 0.05.Results: Lower-limb dynamic stability was descriptively similar between the dominant and non-dominant limbs in the studied female football players. Correlations with Figure-of-8 Hop Test time were negative, indicating that better Y-Balance Test performance was associated with faster hopping performance. Significant associations were observed for non-dominant anterior reach, dominant posterolateral reach, posteromedial reach in both limbs, and the composite score in both limbs. Whereas dominant anterior reach and non-dominant posterolateral reach were not significantly associated with Figure-of-8 Hop Test performance. Overall, the composite score appeared to show the most consistent relationship with Figure-of-8 Hop Test performance.Conclusions: These findings suggest that the Y-Balance Test and Figure-of-8 Hop Test provide complementary information on lower-limb function in female football players. For clinical and training practice, the Y-Balance Test composite score appears to be the most useful screening variable, while individual reach directions may help identify more specific control deficits.