Reliability of single-leg maximal dynamic strength performance and inter-limb asymmetries in pre-pubertal soccer players. The influence of maturity in asymmetries
Nizar Bouafif,
Raouf Hammami,
Abdelkader Mahmoudi,
Pablo Jiménez-Martínez,
Carlos Alix-Fages,
Amador Garcia-Ramos,
Alvaro Juesas,
Javier Gene-Morales,
Sabri Gaied-Chortane,
Juan C. Colado
Affiliations
Nizar Bouafif
Higher Institute of Sport and Physical Education of Ksar-Said, Manouba University, Tunis, Tunisia; Research Unit (UR17JS01) “Sport Performance, Health and Society”, Higher Institute of Sport and Physical Education of Ksar Said, Manouba University, Tunis, Tunisia
Raouf Hammami
Higher Institute of Sport and Physical Education of Ksar-Said, Manouba University, Tunis, Tunisia; Tunisian Research Laboratory ‘Sports Performance Optimization (LR09SEP01), National Center of Medicine and Science in Sports (CNMSS), Tunis, Tunisia
Abdelkader Mahmoudi
Higher Institute of Sport and Physical Education of Ksar-Said, Manouba University, Tunis, Tunisia
Pablo Jiménez-Martínez
Research Group in Prevention and Health in Exercise and Sport (PHES), Department of Physical Education and Sports, University of Valencia, Valencia, Spain; ICEN Institute, Madrid, Spain
Carlos Alix-Fages
Research Group in Prevention and Health in Exercise and Sport (PHES), Department of Physical Education and Sports, University of Valencia, Valencia, Spain; ICEN Institute, Madrid, Spain; Applied Biomechanics and Sport Technology Research Group, Autonomous University of Madrid, Spain
Amador Garcia-Ramos
Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, 18011 Granada, Spain; Department of Sports Sciences and Physical Conditioning, Faculty of Education, Universidad Católica de La Santísima Concepción, Concepción 4030000, Chile
Alvaro Juesas
Research Group in Prevention and Health in Exercise and Sport (PHES), Department of Physical Education and Sports, University of Valencia, Valencia, Spain; Department of Education Sciences, CEU Cardenal Herrera University, Castellón, Spain
Javier Gene-Morales
Research Group in Prevention and Health in Exercise and Sport (PHES), Department of Physical Education and Sports, University of Valencia, Valencia, Spain; Corresponding author. Research Group in Prevention and Health in Exercise and Sport, University of Valencia. Valencia, Spain.
Sabri Gaied-Chortane
Higher Institute of Sport and Physical Education of Ksar-Said, Manouba University, Tunis, Tunisia; Research Unit (UR17JS01) “Sport Performance, Health and Society”, Higher Institute of Sport and Physical Education of Ksar Said, Manouba University, Tunis, Tunisia
Juan C. Colado
Research Group in Prevention and Health in Exercise and Sport (PHES), Department of Physical Education and Sports, University of Valencia, Valencia, Spain
The aims of this repeated measures study were (I) to determine the reliability of single-leg squat 1RM and inter-limb asymmetries in pre-pubertal athletes, and (II) to assess associations between bilateral and/or unilateral squat 1RM performance, inter-limb asymmetries, and participants’ chronological and biological age. Thirty-one soccer players (age [mean ± standard deviation] = 8.48 ± 0.47 years; body mass = 28.32 ± 3.47 kg; body height = 121.70 ± 4.11 cm) practiced two familiarization and two experimental sessions. Bilateral and unilateral squat 1RM and asymmetries between both legs were assessed. Biological age was obtained through the age at peak height velocity (12.87 ± 0.38 years) and maturity offset (3.92 ± 0.44 years). Absolute and relative reliability and Pearson's correlations were calculated. Right and left leg 1RM and asymmetries presented good relative reliability (ICCrange = 0.84–0.85) levels, but non-acceptable absolute reliability (CV ~ 12 %). Asymmetries presented trivial to small correlations with strength (Range = 0.01–0.11). Similarly, chronological, and biological age presented small correlations with strength and asymmetries (Range = 0.01–0.22). Considering the good reliability, the bilateral and unilateral 1RM back half squat test can be considered in youth soccer players. Finally, lower-body mechanical performance and asymmetry between legs show trivial to small correlations, with maturation not affecting asymmetry in male youth soccer players. In conclusion, strength and power activities and training should be placed on younger soccer players with high asymmetry scores regardless of their stage of maturation.
