Study aim: The aim of the study was to evaluate the differences in strength and jumping abilities of adolescent soccer players playing in different positions on the field.
Material and methods: The study included 41 adolescent (14.53 ± 0.68 years old) soccer players: 6 goalkeepers (GK), 13 defenders (DF), 15 midfielders (MD) and 7 strikers (ST). We measured peak torques (PT), total work (TW), and average power (AP) developed by the knee flexors and extensors under isokinetic conditions at angular velocities of 300°·s−1, 180°·s−1 and 60°·s−1 on a Biodex dynamometer, as well as jump height (h), jump depth (d) and power (Pmax) on a force plate.
Results: There was a statistically significant difference in body height between GK (181.17 ± 10.40 cm) and MD (165.60 ± 9.07 cm). PT, AP, TW, h, and Pmax showed no statistically significant differences between the positions on the field. Significant correlations between jumping height and isokinetic measurements of the quadriceps were found in MD (p < 0.05). Correlations between jump power and isokinetic measurements of the quadriceps were found in all types of jumps in the DF and MD groups, whereas no correlation in the bounce counter-movement jump was shown by GK and ST (p > 0.05). MD showed an inverse relationship between the PT, AP, and TW at movement velocities of 300°·s−1 and 180°·s−1, and the jump depth in the akimbo counter-movement jump and counter-movement jump.
Conclusion: The observed differences in correlations between the positions are likely due to the different tasks assigned to the specific position during the match.