Effect of gender and training years on the upper extremity dynamic balance function in adolescent swimmers

Upper extremity dynamic balance is the ability of the upper extremities to sustain stability during exercise. Abnormal upper extremity dynamic balance increases the risk of sport injury in swimmers. However, research on the influencing factors of upper extremity dynamic balance function is limited. This study aims to investigate the factors affecting upper extremity dynamic balance function in adolescent swimmers.

A total of 62 adolescent swimmers were recruited, and their demographic characteristics, such as age, gender, BMI, and other relevant information, as well as details related to their swimming activities, were collected. Participants were categorized into different groups based on the median training years (5 years), gender, and hand dominance, including > 5 years of training experience (expert) and ≤ 5 years of training experience(novice), male and female, as well as dominant and non-dominant hand groups. All participants underwent limb function tests such as upper-extremity star excursion balance test (UESEBT), closed kinetic chain upper-extremity stability test, trunk flexor endurance test and lateral trunk endurance test. The differences in UESEBT performance between different groups were analyzed, and the correlation between UESEBT and different parts of skinfold thickness was examined.

All the individuals were adolescents with an average age of 12.58 ± 2.42 years, height of 150.02 ± 14.43 cm, weight of 45.46 ± 13.25 kg, and body mass index of 17.53 ± 2.33 kg/m². Significant disparities were observed in UESEBT performance among adolescent swimmers varying in years of training, gender, and hand dominance (p < 0.05). Athletes with expert, athletes' non-dominant hand, and males generally exhibited superior stability and higher composite scores in most directions than those with novice, athletes' dominant hand, and females, respectively. UESEBT performance showed a weak negative correlation with skinfold thickness (arm; r = from - 0.250 to - 0.332, p < 0.05).

Training years, gender, hand dominance, and skinfold thickness are important factors affecting upper extremity dynamic balance function in adolescent swimmers. These factors should be considered when selecting swimmers and designing training programs to prevent sports injuries.