| FUNCTIONAL ASYMMETRY OF THE UPPER LIMBS IN FEMALE COLLEGIATE VOLLEYBALL PLAYERS: COMPARISON OF THROWING POWER AND BALANCE BETWEEN DOMINANT AND NON-DOMINANT HANDS |
| Paper ID : 1114-SPORTCONGRESS |
| Authors |
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Zahra Hosseini *, Foad Seidi, Fatemeh Khoshroo Department of Sport Injuries and Corrective Exercise, Faculty of Sports and Health Sciences, University of Tehran |
| Abstract |
| Introduction: In overhead sports such as volleyball, repetitive execution of unilateral movements for skills such as spiking and serving can lead to muscular imbalance and, consequently, to functional asymmetry between the dominant and non-dominant limbs. This study aimed to investigate the degree of upper-limb functional symmetry in female collegiate volleyball players and to compare the performance of the dominant and non-dominant hands. Methods: This descriptive–analytical study was conducted on 52 female collegiate volleyball players (mean age: 22.71 ± 3.26 years; height: 166.37 ± 4.55 cm; weight: 60.26 ± 5.95 kg) who were purposefully selected. Upper-limb performance was assessed using the Upper Quarter Y-Balance Test and the seated unilateral medicine-ball throw test. Data normality was verified using the Shapiro–Wilk test, and paired-sample t-tests were applied to compare the performance of the two hands. The functional asymmetry index (AI) was calculated using the formula: AI (%) = (D – ND) / D × 100, where D represents the performance of the dominant hand and ND represents the performance of the non-dominant hand Results: The performance of the dominant hand in the medicine-ball throw test was significantly higher than that of the non-dominant hand (p < 0.05), while no significant difference was observed in the Y-Balance Test (p > 0.05). The functional asymmetry index was calculated as 5% for throwing power and 0.5% for balance. Conclusion: The findings indicated that female collegiate volleyball players, despite the unilateral nature of volleyball skills, demonstrated an acceptable level of upper-limb functional symmetry. Although the dominant hand showed significantly greater throwing performance, the difference was below the 10% threshold and within the normal adaptive range. However, since prolonged unilateral training may gradually increase performance asymmetry, regular monitoring and implementation of balancing exercises are recommended to maintain coordination and overall functional efficiency. |
| Keywords |
| functional asymmetry, upper limb, dominant hand, volleyball |
| Status: Abstract Accepted (Poster Presentation) |
