Performance and bilateral asymmetries of upper and lower extremity dynamic strength and balance in young soccer players

Abstract

Background Quantification of asymmetry among upper and lower extremities is informative to assess whether an individual may be at risk of injury or performance deficits. In terms of sexes and age differences in functional movement, there is no consistent outcome. The present cross-sectional study aimed to investigate the effects of sex and age on performance and asymmetries in countermovement jump, landing, and upper and lower extremity balance tasks. Method 174 young soccer players (Age 7–9 yrs: 19 females and 15 males; Age 10 − 12 yrs.: 38 females and 30 males; Age 13–17 yrs.: 16 females and 25 males; Age > 18 yrs.: 15 females and 16 males) participated in the study. Countermovement Jump and Landing, Maximum Push-up, and upper and lower extremity balance tests were evaluated for each participant. A repeated measures (age groups × sex) analysis of variance (ANOVA) test was used to compare variables between sexes and age groups (p < .05). Whenever the ANOVA revealed a significant factor, pairwise comparisons were performed using Bonferroni corrections. Result Age played a significant role in peak force from landing, asymmetry of landing peak force, jump height, and peak force from push-up for the right and left sides. In terms of sex effects on dependent variables, statistical significances were observed for jump height, peak force from landing, and peak force from push-up. Except for the asymmetry of landing peak force, no statistical significance is observed in the effects of age and/or sex on the other asymmetry variables. Conclusion Soccer players may need more upper and lower-extremity dynamic balance training to improve dynamic balance over time. Landing technique training should be implemented for young age soccer players to decrease their high landing forces. Asymmetries should be evaluated on an individual basis as their relationships with age and sex were weak.