Affiliations: [a] Department of Physical Education and Sports Science,
Democritus University of Thrace, Komotini, Greece
Note: [] Address for correspondence: Paraskevi Malliou, PhD, Assistant
Professor, Department of Physical Education and Sports Science, Democritus
University of Thrace, 69100 Komotini, Greece. Tel.: 0030 25310 39662; Fax: 0030
25310 39623; E-mail: [email protected]
Abstract: The aim of the present study was to determine the relationship
between vertical jump performance and the isokinetic strength of the knee
extensors in professional soccer players at the end of the of the competition
period, after the detraining period (before the initiation of the preparatory
period) and after the completion of the preparatory period. Eighteen
professional soccer players participated in the present study. The peak jumping
height (of the squat and counter movement jumps on an Ergojump device) was used
as indicator of vertical jump performance. The subjects also performed three
submaximal and three maximal isokinetic efforts of the knee extensors at
angular velocities of 60 and 180°/s. Pearson product
moment correlation analyses were conducted to determine the relationship
between isokinetic strength and jumping parameters. The significance level was
set at p < 0.05. The analysis indicated that jumping height was moderately
correlated with the knee torques at the test velocities after the competition
and preparatory period.
Keywords: vertical jump, isokinetic peak torque, knee extensors, soccer players, training period
