Affiliations: [a] University of Ljubljana, Faculty of Sport, Department
of Sports Medicine, Ljubljana, Slovenia | [b] University of Ljubljana, Faculty of Sport, Department
of Volleyball, Ljubljana, Slovenia | [c] University of Zagreb, School of Kinesiology, Zagreb,
Croatia | [d] University Medical Centre Ljubljana, Department of
Traumatology, Ljubljana, Slovenia
Note: [] Address for correspondence: Vedran Hadzic, MD, University in
Ljubljana, Faculty of Sport, Department of Sports Medicine, Gortanova 22
Street, Ljubljana, Slovenia. E-mail: vedran.hadzic@guest.arnes.si
Abstract: Knowledge of lower-extremity strength can be used in injury
prevention, conditioning and rehabilitation of volleyball players. The goals
were: (1) to describe the bilateral concentric and eccentric quadriceps (Q) and
hamstrings (H) muscle function in volleyball players, (2) to evaluate the
differences in Q and H strength, strength ratios and bilateral strength
asymmetry among age groups, playing positions and playing levels, (3) to
compare bilateral strength asymmetry in Q and H muscles in two different
contraction modes. Ninety five professional male volleyball players were tested
on an isokinetic machine at 60°/s to assess concentric
and eccentric Q and H strength. We also calculated strength ratios and
bilateral strength asymmetries. MANOVAs indicated significant main effect of
playing level on relative PT (p=0.001) and strength ratios
(p< 0.05). International-level players had significantly
(p< 0.05) higher H strength and dynamic control ratio (DCR)
of the right leg compared to the 1st and/or 2nd national division players.
There were no signs of bilateral strength asymmetry regardless of muscle group
tested and contraction mode. Our results suggest that right H strength and DCR
could be important for successful volleyball performance. Descriptive data
about Q and H muscle function can be used as guidelines for coaches and
therapists during training and rehabilitation of male volleyball players.
