Background and objective: There are many studies that have
examined the differences in isokinetic strength performance differences in
athletes; however, observing these angular velocity-dependent differences on
surface maps is a very practical and useful application. The aim of this study
was to determine the angular velocity-dependent isokinetic knee extensor/flexor
muscle strength and jump performance and to compare the test results and 3D
torque-angle-velocity surface maps of amateur and professional volleyball
Materials and methods: We included 25 well-trained male volleyball
players (14 professionals and 11 amateurs) with a mean age of 21.8 2.6
years (range 18–27 years) in this cross-sectional study. The dominant knee
concentric muscle contractions were analyzed at 300, 120, and 60/s
angular velocities to determine peak torque (PT), total work (TW), mean power
(MP), angle of peak torque (APT), and hamstring-to-quadriceps torque ratio (H:Q).
Vertical jump performance was assessed using countermovement jump (CMJ) test.
These data were processed using a MATLAB algorithm for constructing the 3D
torque-angle-velocity surface maps.
Results and conclusions: Significant differences were identified for extensor–flexor
PT between PRO and AT at 300 and 120/s (p 0.05). Moreover, there
were significant differences between groups for MP and APT at 300 and
120/s for TW at all velocities. CMJ test results were significantly
different between the groups (p 0.05). Amateur and professional male volleyball players showed
different concentric knee strengths across isokinetic velocities and different
eccentric strengths on CMJ test. 3D surface maps can play an important role in
the comparative analysis of athletes with different sports backgrounds or in
performance analyses when tracking individual development and provide a detailed
and understandable perspective in revealing differences. It can also be of help
in detection of possible deficits in muscle strength and load range before and
after potential injuries.