Unipedal vertical jumping performance in soccer players

Abstract

Introduction: The muscular strength between the dominant and non-dominant legs of soccer players has been the centre of research that has highlighted contradictory results. Several researchers have reported symmetry between the dominant and non-dominant legs, whereas others suggest the existence of a significant asymmetry. Kicking and cutting skills in soccer are clearly unilateral, require asymmetrical motor patterns and can lead to the development of asymmetrical adaptations in the musculoskeletal function of the lower limbs (Fousekis et al., 2010). The purpose of this study was to examine the flight time [FT] and jump height [JH] during a vertical one-legged countermovement jump by dominant leg [VOL-CMJ-DL] and non-dominant leg [VOL-CMJ-NDL] in soccer players (SPs). Methods: Eighteen male players of a soccer team (soccer training age: 9.22+/-1.47 years), 14 right-footed SPs (age: 14.36+/-0.50 years, height: 1.64+/-0.06 m, body weight: 53.42+/-7.20 Kg, BMI: 19.63+/-1.88) and 4 left-footed SPs (age: 14.25+/-0.50 years, height: 1.65+/-0.06 m, body weight: 57.27+/-10.90 Kg, BMI: 20.70+/- 2.54) were analyzed by Optojump system (Microgate, Bolzano, Italy). The optical acquisition system allowed the measurement of contact and flight time during a jump to a precision of 1/1000s. Results: We did not observe any significant difference in FT and JH during the vertical one-legged countermovement jump by right and left leg in subjects (FT: 0.32+/-0.04 vs. 0.32 +/-0.03 s, JH: 13.80 +/-4.05 vs. 13.20 +/-3.24 cm). Moreover, we did not show any significant influence of subjects’ lateral dominance on unipedal vertical jump performances. In fact, SPs with right lateral dominance showed similar FT (VOL-CMJ-DL: 0.32+/-0.05 vs. VOL-CMJ-NDL: 0.32 +/-0.04 s) and JH (VOL-CMJ-DL: 13.58 +/-4.53 vs. VOL-CMJ-NDL: 13.42 +/- 3.61 cm) during unipedal tests by right and left leg; likewise SPs with left lateral dominance showed similar FT (VOL-CMJ-DL: 0.31+/-0.01 vs VOL-CMJ-NDL: 0.34 +/-0.02 s) and JH (VOL-CMJ-DL: 12.42 +/-1.43 vs VOL-CMJNDL: 14.57 +/-1.79 cm) in VOL-CMJ-DL and VOL-CMJ-NDL. Discussion / Conclusion: These data are in accordance with Capranica et al. (1992) who showed an increase of force and power of both legs regardless of lateral dominance in soccer players. In particular, the balanced muscle power in both lower limbs could decrease the risk of soccer injuries in studied players in agreement with Fousensis et al. (2010) that showed as soccer players with a longer professional training age seem to adopt a more balanced use of their lower extremities to cope with asymmetrical motor patterns of soccer game. References: › Fousekis, K., Τsepis, E. & Vagenas, G. (2010). Lower limb strength in professional soccer players: profile, asymmetry, and training age. Journal of Sports Science and Medicine, 9:364-73. › Capranica, L., Cama, G., Fanton, F., Tessitore, A. & Figura, F. (1992). Force and power of preferred and non-preferred leg in young soccer players. The Journal of Sports Medicine and Physical Fitness, 32(4), 358-63.